Dissertations / Theses on the topic 'Ruminant Meat'

According to FAO, about 9 billion of people will ask for food by 2050. The agriculture challenge is to increase food production by preserving food quality and natural resources. According to WHO, red meat can favor the onset of cardiovascular disease and colon-rectal cancer; however, they are also an important source of vitamin, protein and functional fatty acids (CLA, EPA, DHA). Future animal breeding techniques aims will be improving food nutritional profile and reducing environmental impact at the same time. Rumen lipolysis and bio-hydrogenation allow the synthesis of a pool of fatty acids; this process is affected by animal diet. Pasture feeding increase omega-3 and CLA content in food; however, the problems related to pasture availability ask for innovative techniques that promote their synthesis even if green herbage is not present. The use of plants, or plant-extracts, containing bioactive compounds represents an achievable prospect. The aim of this PhD was to deepen how different plants bioactive compounds affect fatty acid composition in lamb meat. In the first experiment, the use of Trifolium pratensis (containing polyphenol oxidase enzyme, PPO) and Onobrychis viciifolia (containing condensed tannins, CT) silages were tested. The effect of PPO and CT on rumen lipid profile was comparable and even additive when silages were supplied as a mixture. In this case, meat fatty acid profile was similar to pasture-fed animals. In the second experiment, three plants extract were added to lambs diet: hydrolizable tannins from chestnut (Castanea sativa), CT from mimosa (Acacia dealbata) and from gambier (Uncaria gambir). The effect of the different source of tannins on meat fatty acid composition was not very strong; however, multivariate analysis allowed discriminating the different groups.

O presente trabalho teve como objetivo avaliar a dieta de ovinos a base de caroço de algodão sobre parâmetros de desempenho, metabolismo de nutrientes, emissão de metano e qualidade da carne, bem como o efeito acumulativo e sinais de toxicidade causados pela ingesta?o de concentraco?es elevadas de gossipol livre presente na dieta dos animais, garantindo a segurança alimentar. O experimento teve duração de 70 dias, com 16 animais machos deslanados, castrados, da raça Santa Inês, com massa corporal inicial de 44 ± 4,7 kg e idade me?dia de 18 ± 2 meses, divididos em Tratamento Controle (TC) e Tratamento com Caroço de Algodão (TCA). As dietas foram oferecidas diariamente em dois períodos, constituida por 40% de feno de Tifton (Cynodon spp) e 60% de concentrado (50 % milho moido e 50% de soja em grão, e 100% de caroço de algiodão integral, respectivamente para TC e TCA), além da oferta de água e mistura mineral ad libitum. O exprerimento in vivo foi dividido em três períodos, ensaio de desempenho (10 dias de adaptação aos tratamentos e 45 de acompanhamento), ensaio de digestibilidade aparente (5 dias de adapatação e 5 dias de coletas) e ensaio de produção de metano entérico (2 dias de adaptação e 3 dias de coletas). Foram realizadas análises bromatológicas para caracterização dos componentes das dietas, sobras e excrementos, para inferir o consumo e ganho de peso dos animais; avaliação dos parâmetros ruminais de AGGC, ph, N-NH3 e Gossipol livre; e estimativa da produção microbiana, através dos derivados de purinas. Decorridos os 70 dias, os animais permaneceram em jejum de sólidos (16h), em seguida foram abatidos e as carcaças avaliadas. Foram determinados os parâmetros fisíco-químico, de rendimento da carcaça, avalição centesimal, qualidade da carne e gossipol livre. A inclusão de 60% do caroço de algodão no concentrado proporcionou aumento na ingestão, na digestibilidade média de nutrientes e no metabolismo de nitrogênio; permitindo um ambiente propício às atividades dos microrganismos ruminais, evidenciado pelos parâmetros ruminais AGCC, ph e N-NH3 e produção CH4. No entanto, os animais apresentaram menor ganho de peso e rendimento em relação a dieta controle. Os critérios de qualidade da carcaça e na composic?a?o centesimal, não houve diferença. Tendo em conta a qualidade da carne de ovinos Santa Inês, sugere-se que a inclusão de até 60% da alimentação dos animais com caroço de algodão na substituição de milho e soja, no período de terminação, estaria seguro sem causar intoxicação ou alterações na carcaça e, portanto, sem riscos para a saúde humana; contribuindo assim para a produção de alimentos de forma sustentável e segura<br>The aim of this study was to evaluate sheep fed with whole cottonseed on performance parameters, nutrient metabolism, methane emission and meat quality, either the toxixity effect caused by the ingestion of high amount of free gossypol present in animals feed, ensuring food security. The experiment lasted 70 days, using 16 Santa Inês\' sheep, with initial body mass of 44 ± 4,7 kg and mean age of 18 ± 2 months, distributed in Control Treatment (TC) and whole cottonseed Treatment (TCA). The feed were offered daily in two periods, consisting of 40% of Tifton hay (Cynodon spp) and 60% of concentrate (50% corn grains and 50% soybean meal, and 100% whole cottonseed, respectively for TC and TCA), also water and minerals were supplied ad libitum. The in vivo study was divided into three periods, performance assay (10 days of adaptation to treatments and 45 days of assay), apparent digestibility assay (5 days of adaptation and 5 days of assay) and enteric methane emissions (2 days of adaptation and 3 days of assay). Bromatological analyzes of feeds, leftovers and excrements were realized to characterize the components, and to determine consumption and weight gain of the animals; Evaluation of ruminal parameters of short chain faty acids (SCFA), pH, ammonia nitrogen (NH3-N) and free gossypol; also estimation of microbial production through the purine derivatives content in urine. After 70 days, the animals remained fasted (16h), then slaughtered and carcasses were evaluated. Physicochemical parameters, carcass yield, centesimal evaluation, meat quality and free gossypol were determined. The inclusion of 60% of whole cottonseed in the concentrate provided an increase in the intake, average digestibility of nutrients, also the nitrogen metabolism; allowing an environment conducive to the activities of ruminal microorganisms, evidenced by ruminal parameters SCFA, pH, NH3-N and CH4 production. However, the animals had lower weight gain in relation to the control diet. The criteria of carcass quality and centesimal composition did not differ between diets. The presence of free gossypol was not detected neither in meat nor in liver samples. Taking into account the quality of Santa Inês\' meat, it is suggested that the inclusion up to 60% of whole cottonseed animals\' feed, in the confinement termination period would be safe when in substitution of corn and soybeans, without causing intoxication or changes in the carcass, and therefore without risks to human health; contribuiting for the production of food in a secure, safety and sustainable way

Sheep meat is a source of polyunsaturated (PUFA) and monounsaturated (MUFA) fatty acids that confer beneficial effects to human health, but it also contains high concentration of saturated fatty acids (SFA) that are associated with the development of certain diseases. To attain a healthier intramuscular fatty acid composition, that is, meat with high PUFA to SFA ratio, and low in fatty acids n-6 to n-3 ratio, several strategies focused on animal feeding have been tested. However, a sufficient amount of antioxidants must be present in meat to counterbalance the increase in the content of readily oxidizable unsaturated fatty acids, which is vulnerable to oxidation, and from the associated deterioration of meat colour and proteins, thus antioxidants are crucial in preserving the nutritive value and extending the shelf life of the meat. The increasing costs of feedstuffs for livestock led to the utilization of cheaper resources as alternatives to reduce the production cost. Here, locally available materials and agro-industrial by-products commonly found in the Mediterranean countries (citrus pulp, carob pulp, and olive cake) were used in feeding trials with lambs and the effects on meat quality were evaluated. These plant-derived materials contain considerable amounts of secondary bioactive metabolites, which affect the fatty acid composition and/or act as antioxidants. Hence, it was hypothesized that at appropriate levels of inclusion in to the lamb diets, these feedstuffs would not negatively affect animal health and productivity, and would represent a strategy to naturally produce a healthy and oxidatively stable meat. In the first study (Experiment 1), Comisana male lambs were fed for 60 days:a conventional cereal-based concentrate diet, or concentrates in which 24% or 35% dried citrus pulp was included in partial replacement of barley. Following slaughter, the slices of longissimus thoracis et lomborum muscle were packed aerobically and stored for up to 6 days. The inclusion of citrus pulp in the diet effectively inhibited protein oxidation in meat by reducing protein radicals, carbonyl formation, and thiol loss in comparison to the Control. The results showed the ability of citrus pulp to be conveniently included among the ingredients of a concentrate-based diet and to result in an improved oxidative stability of meat proteins.In the second study (Experiment 2), Comisana lambs were fed for 60 days: conventional concentrates or a diet in which cereal concentrates were partially replaced by 24% or 35% carob pulp. The results demonstrated that feeding carob pulp did not affect animal productivity and improved the muscle content of PUFA, among which is rumenic acid, and reduced the SFA concentration and the n-6/n-3 PUFA ratio as compared to the control diet. Moreover, no extensive colour, lipid and protein oxidation in meat were observed over 6 days of aerobic storage. Therefore, dietary carob in lamb diet could be an effective strategy to improve the PUFA content in the meat without compromising animal growth performance and meat oxidative stability. In the third study (Experiment 3), the effect of feeding lambs with diets including linseed and olive cake on the evolution of volatile compounds (VOCs) in meat was assessed. Specifically, Appenninica lambs fed commercial concentrates or diets containing linseed, or olive cake, or combination of both. The VOC profile was determined through SPME-GC-MS analysis of raw and cooked meat The cooked meat showed higher concentrations of VOCs than raw meat and most of these were derived from fatty acid oxidation.Nevertheless, in both raw and cooked meat, none of the lipid oxidation-derived volatiles was significantly affected by the dietary treatments. Therefore, the results suggest that the replacement of cereal concentrates with linseed and/or olive cake in diets for lambs did not cause appreciable changes in VOC profile of meat.

Conselho Nacional de Desenvolvimento Científico e Tecnológico<br>The objective of this study was to evaluate the effect of three carbohydrate sources (corn, soybean hulls or wheat bran) in the diet on performance, carcass characteristics and meat and the components are not part of the carcass of steers finished on confinement. We used 24 steers, crossbred Charolais x Nellore, with initial age of 22 months of initial body weight 353.2 ± 10.6 kg. The animals were fed a diet with roughage: concentrate 40,2:59,8, and the volume consisting of sorghum silage. The daily intakes of DM and CP were not influenced by sources of carbohydrates. Animals fed soybean hulls had higher intake of NDF and ADF, whereas calves receiving corn consumed higher levels of NFC, and TDN ED. Animals fed corn or soybean hulls had greater weight gain and better feed conversion than steers receiving wheat bran. The slaughter weight was similar between the sources of carbohydrates, averaging 429.81; 433.18 and 430.46 kg for maize, soybean hulls and wheat bran, respectively. The weight cut sidecut was greater for steers fed corn diet compared with soybean hulls or wheat bran. The meat from the diet with soybean hulls had better flavor compared to the wheat bran. The loss of the cooking liquid and cholesterol content were higher in animals treated with maize as compared to those receiving soybean hulls or wheat bran. There was no effect of carbohydrate sources on the weights of vital organs and blood. The absolute and relative weights to the weight of empty body fat of the intestines and rumen were higher in animals fed with corn. The weight of the omasum was greater for the diet with wheat bran, while animals fed soybean hulls had higher absolute weight of kidney fat.<br>Objetivou-se neste estudo avaliar o efeito de três fontes de carboidratos (milho, casca de soja ou farelo de trigo) na dieta sobre o desempenho, as características da carcaça e da carne e dos componentes não integrantes da carcaça de novilhos de corte terminados em confinamento. Foram utilizados 24 novilhos castrados, mestiços Charolês x Nelore, com idade inicial de 22 meses e peso inicial de 353,2±10,6 kg. Os animais foram alimentados com dieta com relação volumoso:concentrado de 40,2:59,8, sendo o volumoso constituído de silagem de sorgo. Os consumos diários de MS e PB não foram influenciados pelas fontes de carboidratos. Animais alimentados com casca de soja apresentaram maiores ingestão de FDN e FDA, enquanto que os novilhos que receberam milho consumiram maiores teores de CNF, NDT e ED. Animais alimentados com milho ou casca de soja apresentaram maior ganho de peso e melhor conversão alimentar em relação aos novilhos que receberam farelo de trigo. O peso de abate foi similar entre as fontes de carboidratos, com médias de 429,81; 433,18 e 430,46 kg, para o milho, casca de soja e farelo de trigo, respectivamente. O peso do corte costilhar foi maior para os novilhos alimentados com milho em comparação a dieta com casca de soja ou farelo de trigo. A carne proveniente da dieta com casca de soja apresentou melhor palatabilidade em relação à do farelo de trigo. As perdas de líquidos à cocção e o conteúdo de colesterol foram maiores na carne dos animais tratados com milho em relação aos que receberam casca de soja ou farelo de trigo. Não houve efeito das fontes de carboidratos sobre os pesos dos órgãos vitais e de sangue. Os pesos absolutos e relativos ao peso de corpo vazio dos intestinos e da gordura ruminal foram maiores nos animais alimentados com milho. O peso de omaso foi maior para a dieta com farelo de trigo, enquanto que os animais alimentados com casca de soja apresentaram maior peso absoluto de gordura renal.

Tese de Doutoramento em Ciências Veterinárias, Especialidade de Produção Animal<br>Foram realizados dois ensaios com o objetivo de avaliar os efeitos de duas estratégias nutricionais no perfil lipídico da carne de borregos alimentados com dietas à base de alimento concentrado suplementadas com óleo (60 g/kg de uma mistura de óleo de girassol e de linhaça, 1:2 v/v) i) diferindo no nível de amido e na degradabilidade ruminal do amido ou ii) incluindo argilas como adsorventes do suplemento lipídico.No primeiro ensaio, as diferenças no nível de amido foram conseguidas substituindo parcialmente os cereais por polpa de citrinos desidratada e as diferenças na degradabilidade ruminal do amido foram alcançadas alterando a proporção de milho e trigo nas dietas. As quatro dietas foram: MSMD (35% amido; 70% degradabilidade), MSHD (35% amido; 80% degradabilidade), HSMD (50% amido; 70% degradabilidade) e HSHD (50% amido; 80% degradabilidade). No segundo ensaio foram utilizadas quatro dietas: C (sem argilas), B (30 g/kg de Bentonite), V (30 g/kg de Vermiculite) e BV (15 g/kg de Bentonite + 15 g/kg de Vermiculite). As estratégias nutricionais utilizadas em ambos os ensaios não tiveram efeito sobre o desempenho produtivo dos animais. No primeiro ensaio o aumento da degradabilidade ruminal do amidodiminuiu(-10,3 N ou 1,05 kg) a FC da carne. No segundo ensaio a dieta BV resultou em carcaças com uma maior proporção de HPJ e músculo e com menos GPR e gordura dissecável total. No primeiro ensaio, o teor em lípidos da carne não foi alterado pelas dietas. A redução do nível de amido diminuiu os t-MUFA na carne, em particular o t10-18:1. Os níveis de t11-18:1 e c9,t11-18:2 na carne permaneceram baixos e os de 18:3n-3 permaneceram altos(0,7, <0,3 e 1,74% do total de AG, respetivamente) e inalterados pelas dietas. Os parâmetros fermentativos do rúmen e o perfil de i-BCFAsugerem que a redução do nível de amido terá resultado num aumento do número ou da atividade das bactérias fibrolíticas. Apesar disso, não foi observado qualquer efeito das dietas sobre a extensão ou a completude da BH. No segundo ensaio, não foram observadas diferenças entre dietas nos AGV e nas contagens de protozoários do rúmen. Aextensão da BH do 18:2n-6 ou 18:3n-3 permaneceu inalterada e o teor e o perfil em AG dos lípidos da carne foram bastante semelhantes entre tratamentos. A carne apresentou teores elevados em t10-18:1 e t10,c15-18:2 (≈11 e ≈2,0 g/100 g do total de AG, respetivamente), enquanto o t11-18:1 e o c9,t11-18:2 (≈0,9 e ≈0,2 g/100 g do total de AG, respetivamente) foram bastante baixos. Não foi observado qualquer efeito sobre o teor de 18:2n-6, 18:3n-3 e LC-PUFA da carne. O enriquecimento da carne de borregos produzidos de forma intensiva com AG benéficos para a saúde suplementando as suas dietas com PUFA é limitado pelo shift trans-10 das vias de BH ruminal. Os resultados do presente trabalho sugerem que as estratégias para mitigar o shift trans-10 em borregos engordados intensivamente com dietas suplementadas com PUFA devem ser dirigidas para a redução da ingestão de amido e não tanto para a utilização de fontes de amido de baixa degradabilidade ruminal. A inclusão de argilas como adsorventes de óleos vegetais em dietas à base de alimentos concentrados foi ineficaz na proteção dos PUFA em relação à BH ruminal e na prevenção do shifttrans-10.<br>ABSTRACT - Nutritional strategies in the modulation of ruminal biohydrogenation to improve the fatty acid profile of ruminant’s meat - Two experiments were conducted to evaluate the effects of two nutritional strategies on meat FA profile in lambs fed intensively with high concentrate diets supplemented with oil (60 g/kg of added sunflower and linseed oil blend, 1:2 v/v) and i) differing in starch level and starch rumen degradability or ii) including clays as vegetable oil adsorbent.In the first trial, the dietary differences in starch level were achieved mainly by replacing cereals with dried citrus pulp and differences in rumen starch degradability were achieved by changing the proportions of corn and wheat. The four diets were MSMD (35% starch; 70% degradability), MSHD (35% starch; 80% degradability), HSMD (50% starch; 70% degradability) and HSHD (50% starch; 80% degradability). In the second trial, we used four diets: C (no clay), B (30 g/kg of Bentonite), V (30 g/kg of Vermiculite) and BV (15 g/kg of Bentonite plus 15 g/kg of Vermiculite). The nutritional strategies used had no effect on animal performance. In the first trial, the high degradability diets decreased (-10,3 N or 1,05 kg) meat SF. In the second trial BV diet resulted in higher proportions of HPJ and muscle and lower KKCF and total dissectible carcass fat. In the first trial, lipid content of meat was unaffected by diets. The reduction of starch level decreased t-MUFA, particularly t10-18:1. The t11-18:1 andc9,t11-18:2 remained low and the 18:3n-3 remained high (0,7, <0,3 and 1,74% of total FA, respectively) and unaffected by diets. Rumen fermentation parameters and i-BCFA suggest that starch reduction resulted in an increase in fibrolytic bacteria number or activity. Yet, no significant effect was observed in BH extent or completeness. In the second trial, no differences among diets were observed on rumen VFA and protozoa counts. No effect was observed on 18:2n-6 or 18:3n-3 BH extentand meat total lipids and meat FA profile were very similar among treatments. Meat samples from animals from all diets presented high contents of t10-18:1 and t10,c15-18:2 (≈11 and ≈2.0 g/100 g of total FA, respectively), whereas t11-18:1 and c9,t11-18:2 (≈0.9 and ≈0.2 g/100 g of total FA, respectively) were quite low. No effect was observed in 18:2n-6, 18:3n-3 and LC-PUFA contents in meat. Enrichment of intensively finished lamb with healthy FA using dietary PUFA supplementation is hampered by the trans-10 shifted BH pathways. The results from the present work suggest that strategies to mitigate the trans-10 shift in intensively finishing lambs supplemented with oils rich in PUFA should be directed to reducing dietary starch intake rather than to the use of starch sources with lower rumen degradability.The inclusion of clays as vegetable oil adsorbents in high concentrate based diets were ineffective to protect PUFA from rumen BH as well as to prevent the trans-10 shift.<br>N/A

Tese de Doutoramento em Ciências Veterinárias, especialidade de Produção Animal<br>alexandrafrancisco@sapo.pt<br>Ruminant meats are characterized by being rich in saturated fatty acids (SFA), particularly, and low in polyunsaturated fatty acids (PUFA), which is regarded as disadvantageous for humans. However, ruminant meats are also the dietary source of some bioactive health benefit fatty acids, including conjugated linoleic acid isomers (CLA) and long chain polyunsaturated fatty acids from the n-3 series (n-3 LC-PUFA). In the present thesis we have explored three nutritional strategies to improve the fatty acid (FA) profile of lamb meat, in order to maximize CLA and n-3 LC-PUFA content. Two experiments were conducted to evaluate the effects on lipid metabolism and fatty composition of meat from lambs intensively fattened of the i) dietary inclusion of Cistus ladanifer L. (C. ladanifer); ii) dietary supplementation with vegetable oils and iii) replacement of cereal grains by dehydrated citrus pulp (DCP) in diets. A global evaluation of the effects of the dietary treatments on production, meat quality and meat lipid composition, was achieved by recording the productive performance of lambs, carcasses composition, and determining analytically the fatty acid composition, oxidative stability and organoleptic quality of meat. Moreover, the expression of genes encoding Δ5-, Δ6- and Δ9-desaturases (FADS1, FADS2 and SCD) in longissimus muscle was also assessed. The first experiment, involved 54 Merino Branco lambs, and evaluated the effects of the dietary inclusion of C. ladanifer (rockrose) (Cistus) and of the lipid supplementation with a blend of linseed and soybean oil (2:1 vol/vol). Nine diets were formulated resulting from the combination between 3 levels of C. ladanifer inclusion (50, 100 and 200g/kg of dry matter (DM)) and 3 levels of oil supplementation ((0, 40 e 80g/kg DM)). On second experiment, 32 Merino Branco lambs were fed using diets containing 60g/kg DM of soybean oil and 50% of dehydrated lucerne, and there were evaluated the effects of C. ladanifer inclusion (0 vs 150g/kg) DM) and the replacement of cereal grains by DCP in the diets. On the first experiment, the diets did not affect animal´s growth. Lipid suplementation reduced DM intake, muscle proportion in the carcass and increased kidney knobb channel fat. Meat chemical and physical parameters were not influenced by the diets. The level of 100g/kg of C. ladanifer inclusion improved meat oxidative stability during 7 days of storage. The perception of off-flavours was higher and meat overall acceptability by the sensory panel was reduced with suplementation 8% oil blend. The increasing inclusion of C. ladanifer and oil in the diet act sinergetically on the 10t-18:1 in meat. C. ladanifer increased total amount and proportion of trans monoinsaturated FA (trans MUFA) and reduced the proportions of eicosapentaenoic (EPA) and docosapentaenoic (DPA) acids. The dietary suplementation with vegetable oil blend was a good strategy to improve nutritional value of meat, enhancing total amount of linolenic acid (18:3 n-3) and of n-3 PUFA, and reducing the proportion of SFA, which it was followed by an increment of the proportion of PUFA on lipid profile of intramuscular fat (IMF). The expression of the SCD mRNA increased with C. ladanifer but it was not correlated with the concentration of the Δ9-desaturase FA products. On the second experiment, DM intake increased with C. ladanifer, althought growth was not influenced by diets. Carcass composition was not affected by the dietary treatments, but an interaction between C. ladanifer and DCP was observed for dressing percentage. Dietary factors did not influence muscular pH, cooking losses, meat color and oxidative stability during storage. However, meat shear force increased with the adition of C. ladanifer to diets. Meat tenderness and juiciness were both reduced by C. ladanifer and DCP, but only C. ladanifer reduced meat overall acceptability assessed by the sensory panel. The inclusion of C. ladanifer to 1:1 forage to concentrate ratio diets enriched with soybean oil, reduced the occurrence of trans-10 shift, but did not increase 11t-18:1 and 9c,11t-18:2 concentrations on meat lipids. Trans fatty acids (TFA) were reduced by C. ladanifer inclusion in diets. Dehydrated citrus pulp improved meat nutritional value by increasing 18:3 n-3.<br>RESUMO - Enriquecimento em ácidos gordos bioactivos da carne de borrego de sistema intensivo através da modulação nutricional do metabolismo lipídico - A carne de ruminantes caracteriza-se por ser particularmente rica em ácidos gordos saturados (AGS) e pobre em ácidos gordos poliinsaturados (AGPI), o que é considerado como negativo para a dieta humana. Contudo, é também uma importante fonte de alguns ácidos gordos bioactivos benéficos para a saúde, como os isómeros conjugados do ácido linoleico (CLA) e ácidos gordos poliinsaturados de cadeia longa da família n-3 (n-3 CL-AGPI). Na presente tese explorámos três estratégias nutricionais de modo a melhorar o perfil lipídico da carne de borrego através do aumento do seu conteúdo em CLA e em n-3 n-3 CL-AGPI. Foram realizadas duas experiências nas quais os efeitos i) da inclusão de Cistus ladanifer L. (esteva); ii) da suplementação lipídica com óleos vegetais e iii) da substituição dos grãos de cereais por polpa de citrínos desidratada (PCD) no metabolismo lipídico e na composição em ácidos gordos da carne de borrego de sistema intensivo de engorda foram avaliados. A avaliação integrada dos efeitos dos tratamentos no desempenho produtivo, foi efectuada registando-se a ingestão de matéria seca (MS), ganho médio diário e composição das carcaças dos borregos, assim como a qualidade física e sensorial da carne e a sua composição em ácidos gordos e níveis de expressão dos genes que codificam para as Δ5, Δ6 e Δ9-desaturases (FADS1, FADS2 e SCD mRNAs). No primeiro ensaio, que envolveu 54 borregos Merino Branco avaliámos a inclusão, na dieta, de Cistus ladanifer (esteva), e da suplementação lipídica constituída por uma mistura de óleo de linho e de soja (2:1 vol/vol). Para tal foram formuladas 9 dietas que resultaram da combinação entre 3 níveis de inclusão de C. ladanifer (50, 100 e 200g/kg de matéria seca (MS)) e 3 níveis de suplementação lipídica (0, 40 e 80g/kg de MS). No segundo ensaio, utilizaram-se 32 borregos alimentados com dietas contendo 50% de luzerna desidratada e 60g/kg MS de óleo de soja, e avaliaram-se os efeitos da inclusão de C. ladanifer (0 vs 150g/kg) de MS) e da substituição dos grãos de cereais por polpa de citrínos desidratada (PCD) nas dietas. No primeiro ensaio, os tratamentos não afectaram o crescimento dos animais. O óleo reduziu a ingestão de MS, a proporção de músculo da carcaça e aumentou a quantidade de gordura pélvica e renal. As caraterísticas físicas e químicas da carne não foram afectadas pelas dietas. O nível de 100g/kg de esteva melhorou a estabilidade oxidativa da carne durante o armazenamento de 7 dias. A percepção de off-flavours foi superior e a aceitação global por parte do painel de provadores foi inferior para a suplementação com 8% de óleo. A inclusão de C. ladanifer potenciou o aumento de 10t-18:1 na carne induzido pelo óleo. Com a inclusão de C. ladanifer nas dietas aumentou a quantidade total e proporção de ácidos gordos monoinsaturados trans (TransAGMI) e diminuiram as proporções dos ácidos eicosapentaenoico (EPA) e docosapentaenoico (DPA). A suplementação das dietas com a mistura de óleos vegetais foi uma boa estratégia para melhorar o valor nutricional da carne, permitindo um aumento da quantidade total de ácido linolénico (18:3 n-3) e n-3 AGPI, e a redução da proporção de AGS acompanhada de um aumento da proporção de AGPI no perfil lipídico da gordura intramuscular. A expressão do mRNA do gene SCD aumentou com a inclusão de C. ladanifer nas dietas. No segundo ensaio, a ingestão de MS aumentou com a inclusão de C. ladanifer, embora o crescimento não tenha sido influenciado pelas dietas. A composição da carcaça não foi afectada pelos tratamentos, mas verificou-se uma interacção entre a inclusão de esteva e a de PCD que afectou o rendimento da carcaça. Os factores em estudo não influenciaram o pH muscular, as perdas por cozedura, a cor da carne e a sua estabilidade oxidativa. No entanto, ocorreu um aumento da força de corte da carne com a adição de C. ladanifer às dietas. A tenrura e a suculência da carne sofreram uma diminuição com a inclusão de C. ladanifer e de PCD nas dietas, no entanto a aceitação global da carne pelo painel de provadores apenas foi diminuída com C. ladanifer. A inclusão de C. ladanifer a dietas com uma relação de forragem: concentrado de 1:1 e enriquecidas com óleo de soja, reduziu a ocorrência do trans-10 shift, embora não tenha aumentado os teores de 11t-18:1 e de 9c,11t-18:2 na fracção lipídica da carne. O total de ácidos gordos trans (AGT) na carne foi reduzido pela inclusão de esteva nas dietas. A PCD melhorou o valor nutricional da gordura da carne de borrego, aumentando a concentração em 18:3 n-3.

Includes bibliographical references (leaves 196-220) Studies the growth, body composition, feed intake of grazing animals, the use of anabolic agents, fatty acid composition of ruminants fats; and, the effect of saturated fat on human health.

Nowadays meat quality perception is multifactorial and, especially for red meat, consumers are becoming more and more critics about sensory traits and concerned about psychological and ethical aspects, such as sustainability, animal welfare, antibiotics utilization, safety and healthiness. Address to these topics is fundamental for red meat industry, in order to counteract the decreasing consumption in western countries and to improve production efficiency to fulfill the growing demand from developing countries. Improving all the aspects related to perceived quality will lead to meet consumer satisfaction, with positive impact on demand, and to increase production efficiency and profitability. The following trials aimed to evaluate specific dietary supplements and on farm and post farm strategies to improve animal health, strictly connected with sustainability, animal welfare and production efficiency, and meat appearance and eating quality. 8.1. Trial 1 Bovine respiratory disease (BRD) represents a concern for veal industry, as it causes economic losses, reduces animal welfare and increases antibiotics utilization. A field study to evaluate the effects of multivalent vaccination on veal calves’ health and performance was carried out. 944 healthy calves were randomly allotted into two separate barns. One group was vaccinated 7 days after arrival with quadrivalent vaccine against IBR, PI3, BRSV and BVDV Type 1 viruses plus booster administration 21 days apart (VAC; 675 calves), while the second group was not treated (CON; 269 calves). Vaccination did not affect overall mortality (P=0.75) and mortality due to BRD (P=0.28), while it reduced BRD morbidity (P=0.009). VAC group showed better average daily gain (ADG; P=0.03) and carcass weight (P<0.001). Vaccination delayed the peak of BRD by nearly two weeks (P<0.001) and represented a protective factor against BRD (OR 0.55; P=0.001). BRD increased mortality (P=0.01), lowered ADG (P<0.001) and carcass weight (P<0.001), increased the amount of discounted carcasses (P<0.001). Lung lesions and pleuritis and/or consolidations increased with BRD (P=<0.001) but were unaffected by vaccination (P=0.40 and P=0.43 respectively). In conclusion, BRD impaired veal calves’ health, growth and carcass value and vaccination reduced BRD morbidity, thus improving carcass value. 8.2. Trial 2 Selenium (Se) is involved in several biological functions and its supplementation is necessary for farm animals. Se can be provided in organic or inorganic forms, the former characterized by a higher bioavailability. Despite organic supplementation generally increased the meat Se, inconsistencies in the effects on meat quality have been reported and only one short–term supplementation study has been performed. The study aimed to compare the effects of switching the Se source in the last 60 days of fattening on growth performance, beef quality and Se content. Charolaise beef heifers supplemented since the beginning of the fattening period with sodium selenite (162 heads; 517±61 days of age) were divided into two groups, fed the same diet, in which Se (0.2 mg Se/kg DM of feed) was provided as sodium selenite (SS; 82 heads, 450.36±33.69 kg BW) or selenium-enriched yeast (Se-Y; 80 heads, 454.60±41.70 kg BW). Live weight was measured at the beginning and at the end of the trial and meat samples were collected from 30 homogeneous carcasses/group 48 hours post mortem to evaluate centesimal composition, Se content, shear force and cooking loss. Colour, pH, water holding capacity and appearance were evaluated daily for 8 consecutive days of aerobic storage. The Se source did not affect growth performance, meat centesimal composition, thawing loss, cooking and drip loss and pH during 8 days of aerobic storage. Se-Y supplementation improved the meat Se content (P<0.001) and tended to reduce shear force (P=0.076). Lightness (P<0.01) and yellowness (P<0.01) decreased with the duration of storage and were higher in the Se-Y group compared with the SS group. Meat from group Se-Y also showed a better visual score for color (P<0.01), odor (P<0.05), surface wetness (P<0.05), and overall appearance (P<0.01). Under the presented experimental conditions, switching selenium supplementation from sodium selenite to selenium-enriched yeast during the last two months of fattening did not affect heifer performance or meat water holding capacity, but improved meat tenderness and color stability during storage, with a positive impact on meat shelf life. The present study also confirmed that short-term supplementation represents a valid strategy for increasing meat Se content. 8.3. Trial 3 Inadequate concentration of vitamin E affect retail color and oxidative stability. Vitamin E (VitE) can be supplemented as synthetic all-rac α-tocopheryl acetate or through antioxidant-rich feed as lucerne. The study compared the effects of feeding lambs with a grain based diet at moderate (MOD 42 mg∙kg-1 VitE E as all-rac α-tocopheryl acetate) or supranutritional (SUP 285 mg∙kg-1 of vitamin E all-rac α-tocopheryl acetate) levels of vitamin E and organic selenium or a lucerne based diet (LUC; 37 mg∙kg-1 VitE) for 8 weeks before slaughter. Forty-eight lambs blocked by sex (wethers or females) and feed intake in the last three days of adaptation were randomly assigned to one of the three dietary treatments (16 lambs/treatment). Treatment did not affect DMI (P=0.46) and ADG (P=0.76). LUC group showed lower n-6 and PUFA compared to both MOD (P<0.01) and SUP (P<0.01). Despite a similar VitE intake, muscle vitamin E was higher for LUC compared to MOD (P<0.05), while SUP fed animals showed the highest content (P<0.01). Although that, fresh muscle from LUC showed a better a* stability during 4 days display time compared to MOD and SUP, while no differences were evident considering 6-weeks aged muscles. Oxidative stability measured with T-bars method, did not differ between groups at the beginning and at the end of display life for both fresh and aged muscles. Increasing dietary vitamin E in finishing lambs increased muscle vitamin E content. However, finishing lambs on Lucerne improved color stability of fresh lamb meat, compared to the artificial form. 8.4. Trial 4 Tenderness is one of the main factors affecting consumer preferences and consumers expect veal to be tender. Post mortem ageing improves meat tenderness but, since veal is not commonly aged in commercial practices, it is necessary to evaluate the effects of long-term chilling storage not only on meat tenderness, but also on the physical and sensory properties. The study evaluated the effects of vacuum ageing (2, 4, 6, 8, 10, 12, 16 days) on veal loin (longissimus dorsi; LD) and silverside (biceps femoris; BF) physical and sensory characteristics. Entire cuts were collected from 8 homogeneous carcasses and each divided into eight subsamples, vacuum packed and assigned to one of the seven different ageing treatments and the remaining one was used for chemical composition. Distribution has been done ensuring that each portion of the muscle was equally represented in each ageing time. LD was selected due to its economic significance, while BF is recognized as a less tender hindquarter beef cut when dry-heat cooked. Ageing did not affect cooking loss, increased LD pH and L*, a* and b* in both muscles. shear force (SF) decreased until day 6 in LD and day 10 in BF. Aroma, flavour and taste were not affected, while texture traits were improved. SF was negative correlated with tenderness and juiciness and positive correlated with BF fibrousness and stringy sensation. Postmortem ageing under vacuum conditions improved the instrumental and sensory tenderness without alteration of aroma, flavour, taste and juiciness measured after frozen storage and thawing. Ageing, coupled with freezing and thawing, did, however, reduce the oxidative stability in both muscles, without altering cooking loss and pH. The improvements in LD tenderness and related sensory traits occurred mainly during the first week of postmortem ageing, while in BF, effects were also evident until day 10. Under these experimental conditions, a minimum period of 4 days for LD muscle, and 8 days for BF muscle was necessary to obtain a clear tenderizing effect.

Linseed meal (LSM) was fed to ovariectomized ewes exposed to estradiol 17-? (E2) implants over time, and LSM was supplemented to beef cows during late gestation and early lactation to evaluate the estrogenic potential of the phytoestrogen secoisolariciresinol diglycoside (SDG) found in LSM. Forty-eight ovariectomized ewes were fed a diet containing 12.5% LSM for 0, 1, 7, or 14 d and implanted with estradiol-17? (E2) for 0, 6, or 24 h before tissue collection. Uterine cellular proliferation, vascularity, and the expression of the angiogenic factors and their receptors were recorded. There was an interaction of LSM and E2 on uterine mass (P = 0.05). At 24 h of E2 exposure, proliferation was reduced (P < 0.001) when ewes were fed for 14 d compared to being fed 0 or 1 days. There was a LSM x E2 interaction (P ? 0.03) on VEGF receptor-2 (KDR) and hasicfihrohlast growth factor receptor (FGFR2) decreasing by 24 h E2 exposure. Exposure of LSM and E2 may impact the estrogenic response of sensitive tissue. Two studies were conducted to examine the effects of supplementing beef cows with LSM during late gestation or early lactation on calf growth and development. In Experiment 1, multiparous cows received either LSM or a control (CON) supplement (approximately 10% diet dry matter) for the last 60 d of gestation. Offspring weights, ADG, heifer age at puberty, conception percentage and steer carcass characteristics were recorded. In Experiment 2, multiparous cows received LSM or CON supplements (approximately 10% diet dry matter) during the first 60 d of lactation, and only heifer calf development performance was observed and recorded. Heifer calf weight, average daily gain, and attainment of puberty were assessed. For both experiments, birth weight, weaning weight and ADG were not affected (P > 0.31) by LSM supplementation. While final body weights were heavier (P = 0.04) for steer calves in Experiment 1, there was no effect (P = 0.09) of supplementation on carcass characteristics. In Experiment 1 and 2, attainment of puberty in heifer calves was not influenced (P > 0.58) by supplement type. Linseed meal supplementation during late gestation or early lactation does not appear to have a negative impact on calf growth, onset of puberty in heifer calves, or steer carcass quality, implicating that it may make a good supplement choice in cattle.

Tese de Doutoramento em Ciências Veterinárias, especialidade de Segurança Alimentar<br>Nos tempos que correm estamos cada vez menos disponíveis para a preparação de uma refeição, não existindo, na maioria das vezes, a preocupação de como a processamos e as alterações ocorridas em termos de composição nutricional. Tal como é sabido desde há longa data, a carência de determinados nutrientes pode conduzir a graves problemas de saúde, sendo deste modo imprescíndivel o conhecimento dos fatores que contribuem para minimizar a perda de nutrientes dos alimentos. Considerando que a maioria dos alimentos de origem animal antes de serem consumidos são submetidos a um método de confeção, utilizando-se uma fonte de calor, considerou-se importante avaliar a forma como três métodos de confeção de uso vulgar a nível doméstico (forno micro-ondas, água fervente e grelhagem) poderiam influenciar a composição nutricional das carnes de vitela Barrosã e de novilho Mertolengo (Denominação de Origem Protegida). Assim, no presente estudo, verificou-se que a aplicação dos vários métodos de confeção estudados altera a composição nutricional da carne, não sendo possível identificar no global qual o método de confeção que minimiza as perdas de nutrientes. De acordo com os dados obtidos, verificou-se que em ambas as carnes, os nutrientes que apresentam retenções mais elevadas são as proteínas totais, os aminoácidos, os lípidos totais, os isómeros conjugados do ácido linoleico, o colesterol total, o ferro, o magnésio e o zinco. Em contrapartida, os nutrientes da carne que são mais afetados pela ação dos métodos de confeção são a humidade, os ácidos gordos polinsaturados, o potássio e o α-tocoferol. Por conseguinte, verificou-se que a retenção dos nutrientes da carne varia em função do método de confeção aplicado. Observou-se também um efeito significativo do músculo em alguns dos nutrientes determinados em ambas as carnes estudadas. Os métodos de confeção afetaram negativamente a qualidade nutricional dos lípidos, uma vez que em ambas as carnes se verificou um aumento do índice de aterogenicidade e uma diminuição dos índices hipocolesterolémico/hipercolesterolémico e ácidos gordos polinsaturados/ácidos gordos saturados, comparativamente ao teor obtido na carne crua.<br>ABSTRACT - The effect of different cooking methods on the nutritional value of veal - experimental study on Barrosã and Mertolenga-PDO - Nowadays we often feel short of time when it comes to the preparation of a meal, and most of the time give no consideration as how we process it and the modifications which occur in terms of nutritional composition. It has been known for a long time that the lack of certain nutrients can lead to serious health problems; therefore it is fundamental to acknowledge the factors that contribute to minimizing the loss of food nutrients. Whereas most food of animal origin is subjected to a cooking method using a heat source before consumption, it was considered important to assess how three common household cooking methods (microwave, boiling and grilling) could influence the nutritional composition of Barrosã and Mertolengo veal (Protected Designation of Origin). Thus, in the present study, it was found that the application of the various cooking methods studied modifies the nutritional composition of the meat, without it being possible to identify globally which cooking method minimizes the loss of nutrients. According to the data obtained, it was established that in both meats, nutrients that showed higher retentions are total proteins, amino acids, total lipids, the conjugated isomers of linoleic acid, total cholesterol, iron, magnesium and zinc. In contrast, the meat nutrients that are most affected by the action of cooking methods are moisture, polyunsaturated fatty acids, potassium and α-tocopherol. The results established that the retention of meat nutrients varies depending on the confection method applied. A significant effect of muscle in certain nutrients in both meats studied was also observed. The cooking methods adversely affected the nutritional quality of lipids, since in both meats there was an increase in the atherogenicity index and a decrease in hypocholesterolemic / hypercholesterolemic ratios and polyunsaturated/saturated fatty acids ratios when compared to the level obtained in raw meat.

This research activity aimed at investigating cow and goat milk and cheese quality, organic beef quality in mountain areas. Experimental trials were set-up to evaluate the chemical, technological, and nutritional characteristics of products obtained in organic and conventional farms located in the Veneto region. From the first study on the quality of milk from organic and conventional farms in mountain areas the milk was found to be substantially similar for chemical composition and technological properties despite two production systems were used. The fatty acid profile, instead was viewed favorably from a nutritional point of view for milk obtained form organic farming. Based on the trial carried out on cheese made from organic and conventional milk the differences in fatty acid profiles were confirmed, once again in favor of organic cheeses. It is possible to use some of the fatty acid profile parameters (saturated, mono-unsaturated, poly-unsaturated fatty acids, and ratio for some fatty acids of nutritional interest), to distinguish cheese based on the production system used and period of production. Special interest is paid for poly-unsaturated fatty acids, n3 and CLA fatty acids, which are found in cheeses produced in summer from organic milk. Organic cheese is more yellow and brighter in colour than conventional cheese because it is richer in a-tocopherols. From the sensory analysis no distinctive characteristics resulted for organic cheeses, so it is not possible to distinguish them from conventional ones through taste trials. In the third study, the investigation carried out on organic dairy goat farms in the Veneto region has shown great variability in feed management in farms. Regarding the fatty acid profile for goat milk, the study has revealed better results when grazing was possible; particularly high concentrations of CLA were found in farms where grazing was allowed in the summertime. In the fourth study, organic calf farming results in leaner animals, with lower cholesterol content, compared to conventionally farmed calves. The quantity of haeminic iron in organic meat almost doubles that found in conventional meat, which causes organic meat to be darker. This aspect is viewed negatively form a commercial point of view: darker meat is not appreciated by consumers who expect it to be slightly pink in colour (“white meat”). Overall, with this thesis it was possible to affirm that organic-farming mountain livestock could be exemplified as the method to use for increase the value of productions and sustainable farming.<br>Questa attività di ricerca ha avuto come obiettivo quello di investigare la qualità del latte bovino e caprino, di formaggi e di carne di vitello ottenuto da allevamenti biologici in zona montana. Sono state impostate quattro prove sperimentali che hanno valutato le caratteristiche chimiche, tecnologiche e nutrizionali di prodotti ottenuti da allevamenti biologici e convenzionali localizzati nella Regione Veneto. Il primo studio sulla qualità del latte ottenuto da allevamenti biologici e convenzionali di vacche da latte in zona montana ha evidenziato una sostanziale similitudine nella composizione chimica e nelle caratteristiche tecnologiche del latte ottenuto con i due diversi sistemi di produzione. Il profilo acidico del grasso del latte, invece, è risultato più favorevole dal punto di vista nutrizionale nel latte ottenuto da allevamenti biologici. Nel secondo studio sui formaggi ottenuti con latte biologico e convenzionale sono state confermate le differenze relative al profilo acidico, risultato ancora una volta più favorevole nei formaggi biologici. E’ stato possibile utilizzare alcuni parametri del profilo acidico per poter discriminare formaggi ottenuti con sistemi di produzione diversi e in mesi diversi. In particolare la quantità di acidi grassi polinsaturi, il contenuto di acidi grassi della serie n3 e i CLA, sono risultati più elevati nei formaggi estivi di produzione biologica. L’elevato contenuto di a-tocoferolo rilevato nel formaggio biologico ha portato a una colorazione brillante e più gialla rispetto ai formaggi convenzionali. Dall’analisi sensoriale non sono emerse particolari caratteristiche del formaggio ottenuto con latte biologico che quindi non è possibile discriminare rispetto ai convenzionali con prove di degustazione. Nel terzo studio, l’indagine riguardante le aziende biologiche di capre da latte presenti nella Regione Veneto, ha evidenziato una grande variabilità nella gestione alimentare delle aziende. Il lavoro ha rilevato concentrazioni elevate di CLA nelle aziende che hanno effettuato pascolo per tutti i mesi estivi. Nel quarto studio la carne di vitello ottenuta con metodo biologico è risultata più magra e con un più basso contenuto di colesterolo rispetto alla carne di vitello convenzionale. Il quantitativo di ferro eminico nella carne biologica è risultato quasi il doppio rispetto alla carne convenzionale causando una colorazione più rossa della carne biologica. Questo aspetto può penalizzare la commerciabilità del prodotto in quanto una colorazione rossa della carne di vitello non è apprezzata dal consumatore che desidera una carne rosata (carne “bianca”). Nel complesso questa attività di ricerca ha permesso di affermare che la zootecnia biologica in montagna si può proporre come metodo per la valorizzazione di alcune produzioni e la sostenibilità degli allevamenti.

Tese de Doutoramento em Ciências Veterinárias, especialidade de Segurança Alimentar<br>The aim of this study was to determine the influence of slaughter season and muscle type on nutritional quality of intramuscular fat (IMF) in Mirandesa-PDO (Protected Designation of Origin) veal, Charneca-PDO beef and organic beef, assessing to the quality and status that may contribute to market differentiation. The results suggest that the IMF content of PDO veal, PDO beef and organic beef was slightly affected by the slaughter season but markedly changed by the muscle type. The meat analysed had a high nutritional value, with favourable ratios of n-6/n-3 and contents of n-3 PUFA and α-tocopherol. Some studies indicate that increasing the stearoyl-CoA desaturase (SCD) expression and activity may significantly improve the nutritional quality of meat by decreasing the SFA content, while increasing rumenic acid content. This can be achieved by the administration of gluconeogenesis precursors, such as propylene glycol, which induces elevated propionate in the rumen and higher levels of blood insulin and glucose, resulting in the SCD activity elevation. Thus, the influence of dietary gluconeogenesis precursors (propylene glycol and calcium propionate mix; PP) and linseed oil on intramuscular fatty acid composition of lambs was assessed. Results suggest that gluconeogenesis precursors modify the biohydrogenation pathway and reduce the rumenic acid concentration. Linseed oil supplementation increased meat concentration of α-linolenic acid, as well as most of the C18 biohydrogenation intermediates, including vaccenic acid and rumenic acids. In conclusion, regarding the lipid composition of IMF, the studied PDO and organic meats have a high nutritional value, contributing to the consumer`s confidence on these products. The fatty acid profile of lamb’s IMF was slightly affected by PP, without clear effects on insulinaemia and delta-9 desaturation, demanding future research on this subject.<br>RESUMO - Influência da sazonalidade, do tipo de músculo e de precursores da neoglucogénese na qualidade da gordura intramuscular de carne de ruminantes - Neste trabalho estudou-se o efeito da sazonalidade do abate e do tipo de músculo na qualidade da gordura intramuscular das carnes Mirandesa-DOP (Denominação de Origem Protegida) e Charneca-DOP, e da carne biológica, de modo a avaliar a qualidade e reputação alegada como fator diferenciador no mercado. Os resultados sugerem que a composição de ácidos gordos da gordura intramuscular das carnes analisadas foi influenciada ligeiramente pela sazonalidade do abate mas fortemente pelo tipo de músculo. Apesar desta variação, todas as carnes analisadas têm um elevado valor nutricional apresentando um índice favorável n-6/n-3 e teores elevados de n-3 PUFA e α-tocoferol. Alguns estudos indicam que o aumento da atividade da Δ-9 dessaturase pode melhorar a qualidade nutricional da carne, através da diminuição dos ácidos gordos saturados e do aumento do teor de ácido ruménico. Isto pode ser possível pela administração de precursores neoglucogénicos, tais como o propilenoglicol que induz o aumento do propionato no rúmen e aumenta os níveis sanguíneos de insulina e glucose, resultando no aumento da atividade da Δ-9 dessaturase. Assim foi avaliado o efeito da suplementação da dieta com propilenoglicol e propionato de cálcio, bem como óleo de linho, na composição lipídica da gordura intramuscular da carne de borrego. Os resultados sugerem que os precursores neoglucogénicos alteram a biohidrogenação ruminal e diminui o teor de ácido ruménico. A suplementação com óleo de linho aumenta o teor de ácido α-linolénico da carne, bem como a maioria dos C18 intermediários da biohidrogenação, incluindo os ácidos vacénico e ruménico. Em conclusão, a composição lipídica da gordura intramuscular das carnes de bovino DOP estudadas e da carne biológica apresenta um elevado valor nutricional, contribuindo para confiança do consumidor sobre estes produtos O perfil dos ácidos gordos da gordura intramuscular da carne de borrego é ligeiramente influenciado pelos precursores, sem efeitos claros na insulinemia e na Δ-9 dessaturase, exigindo-se estudos futuros sobre este assunto.<br>FCT - SFRH/PROTEC/2009/50138 and Co-financed by the grant PTDV/CVT/2006/66114

Tese de Doutoramento em Ciência e Tecnologia Animal<br>Contribuição para o estudo da composição lipídica e do valor nutricional da gordura intramuscular na carne de ruminantes - A composição em ácidos gordos e o ácido linoleico conjugado (CLA) são temas actuais de grande interesse, com particular relevância para a qualidade da carne e saúde humana. As carnes de ruminantes têm sido consideradas alimentos pouco saudáveis, principalmente devido à sua fracção lipídica com elevada concentração em ácidos gordos saturados. Contudo, as gorduras edíveis dos ruminantes são a principal fonte natural de isómeros CLA, sendo os isómeros bioactivos (c9,t11 e t10,c12) associados a propriedades potencialmente benéficas para a saúde humana. Em Portugal, a informação científica disponível para apoiar a qualidade e a reputação da carne bovina de raças autóctones criadas segundo as especificações de Denominação de Origem Protegida (DOP) continua restrita. Para além disso, os dados disponíveis não permitem ter uma percepção global de como distintos factores influenciam a composição da carne, desde a sua produção até ao consumo. Neste contexto, a nossa investigação foi desenvolvida estudando o efeito dos regimes alimentares dos animais (pastagem×concentrado), processamento tecnológico da carne após o abate (irradiação) e tratamentos térmicos (fervura, microondas e grelhagem), no perfil lipídico, especialmente nos isómeros do CLA, e no valor nutricional de carne de ruminantes. Foram seleccionadas e caracterizadas 4 carnes tradicionais DOP (Carnalentejana, Mertolenga, Barrosã e Arouquesa). Os resultados sugerem que a gordura intramuscular das carnes de novilho relativamente às de vitela, apresentam menor valor nutricional ao longo do ano, devido ao sistema de produção semi-extensivo utilizado nos novilhos. Por sua vez, a Carnalentejana-DOP apresenta uma qualidade nutricional superior comparativamente à carne de vaca de produção intensiva. No sentido de avaliar em detalhe o efeito de diferentes regimes alimentares no valor nutricional dos lípidos da carne, bem como a sua utilidade como discriminantes químicos da origem da carne, realizou-se um ensaio controlado. Os dados obtidos reforçam os resultados anteriores que sugeriam que a carne de animais de pastoreio apresenta melhor qualidade nutricional (teores mais elevados de n-3 PUFA e CLA) do que a carne de animais alimentados a concentrado. Este facto traduz os efeitos benéficos da pastagem no perfil de ácidos gordos da carne. Relativamente às alterações na composição da gordura intramuscular, resultantes do efeito de processamentos seguintes ao abate, a irradiação, uma tecnologia prospectiva para a conservação das carnes, não promoveu modificações significativas. Os tratamentos térmicos, frequentemente utilizados em culinária, induziram um impacto moderado no perfil dos ácidos gordos, como consequência das perdas de humidade e concentração da gordura. Em resumo, a composição lipídica da gordura intramuscular das carnes de bovino DOP estudadas apresenta um valor nutricional acrescentado para os consumidores, considerando os valores de n-3 PUFA, CLA (total e do isómero c9,t11) e da razão n-6/n-3, contribuindo para a sua diferenciação no mercado.<br>RESUMO - Contribuição para o estudo da composição lipídica e do valor nutricional da gordura intramuscular na carne de ruminantes - A composição em ácidos gordos e o ácido linoleico conjugado (CLA) são temas actuais de grande interesse, com particular relevância para a qualidade da carne e saúde humana. As carnes de ruminantes têm sido consideradas alimentos pouco saudáveis, principalmente devido à sua fracção lipídica com elevada concentração em ácidos gordos saturados. Contudo, as gorduras edíveis dos ruminantes são a principal fonte natural de isómeros CLA, sendo os isómeros bioactivos (c9,t11 e t10,c12) associados a propriedades potencialmente benéficas para a saúde humana. Em Portugal, a informação científica disponível para apoiar a qualidade e a reputação da carne bovina de raças autóctones criadas segundo as especificações de Denominação de Origem Protegida (DOP) continua restrita. Para além disso, os dados disponíveis não permitem ter uma percepção global de como distintos factores influenciam a composição da carne, desde a sua produção até ao consumo. Neste contexto, a nossa investigação foi desenvolvida estudando o efeito dos regimes alimentares dos animais (pastagem×concentrado), processamento tecnológico da carne após o abate (irradiação) e tratamentos térmicos (fervura, microondas e grelhagem), no perfil lipídico, especialmente nos isómeros do CLA, e no valor nutricional de carne de ruminantes. Foram seleccionadas e caracterizadas 4 carnes tradicionais DOP (Carnalentejana, Mertolenga, Barrosã e Arouquesa). Os resultados sugerem que a gordura intramuscular das carnes de novilho relativamente às de vitela, apresentam menor valor nutricional ao longo do ano, devido ao sistema de produção semi-extensivo utilizado nos novilhos. Por sua vez, a Carnalentejana-DOP apresenta uma qualidade nutricional superior comparativamente à carne de vaca de produção intensiva. No sentido de avaliar em detalhe o efeito de diferentes regimes alimentares no valor nutricional dos lípidos da carne, bem como a sua utilidade como discriminantes químicos da origem da carne, realizou-se um ensaio controlado. Os dados obtidos reforçam os resultados anteriores que sugeriam que a carne de animais de pastoreio apresenta melhor qualidade nutricional (teores mais elevados de n-3 PUFA e CLA) do que a carne de animais alimentados a concentrado. Este facto traduz os efeitos benéficos da pastagem no perfil de ácidos gordos da carne. Relativamente às alterações na composição da gordura intramuscular, resultantes do efeito de processamentos seguintes ao abate, a irradiação, uma tecnologia prospectiva para a conservação das carnes, não promoveu modificações significativas. Os tratamentos térmicos, frequentemente utilizados em culinária, induziram um impacto moderado no perfil dos ácidos gordos, como consequência das perdas de humidade e concentração da gordura. Em resumo, a composição lipídica da gordura intramuscular das carnes de bovino DOP estudadas apresenta um valor nutricional acrescentado para os consumidores, considerando os valores de n-3 PUFA, CLA (total e do isómero c9,t11) e da razão n-6/n-3, contribuindo para a sua diferenciação no mercado.<br>This work was co-financed by Centro de Investigação Interdisciplinar em Sanidade Animal (Project CIISA/52.Carne-Bioactivos) da Faculdade de Medicina Veterinária da Universidade Técnica de Lisboa and Fundação para a Ciência e a Tecnologia (POCTI/CVT/2002/44750) and Ministério da Agricultura (AGRO/2003/512).

Resumo: Objetivou-se com este estudo avaliar as características qualitativas da carne, a composição química e de ácidos graxos dos cortes do contrafilé (Longissimus thoracis) e a composição química e de ácidos graxos da picanha (Biceps femoris) de 35 tourinhos da raça Nelore abatidos com peso de 532,17 ± 30,2 kg e 24 meses de idade. Estes animais foram confinados por 96 dias e receberam dietas contendo cana-de-açúcar (var. IAC86-2480) e concentrado com diferentes fontes de óleos protegidos ou não da degradação ruminal; todas as dietas possuíam a relação volumoso:concentrado de 40:60 na matéria seca. Após o período de engorda os animais foram enviados a um frigorífico comercial, abatidos e depois do resfriamento das carcaças, foi retirada uma seção que compreendia da 9a à 13a costelas do músculo Longissimus thoracis e uma peça padronizada, de acordo com o estabelecimento, do músculo Biceps femoris e trazidas ao laboratório para posteriores análises. O delineamento utilizado foi em blocos casualizados com 5 tratamentos e 7 repetições, sendo as médias comparadas por contrastes ortogonais. As análises da qualidade da carne não mostraram diferenças significativas para força de cisalhamento, pH, cor da carne, da gordura e perdas no cozimento. A capacidade de retenção de água evidenciou diferenças, sendo que, o óleo de linhaça protegido foi o tratamento que apresentou os maiores valores em relação aos demais (73,67 vs. 70,89%, respectivamente). A avaliação sensorial feita por painel de degustação treinado, analisadas estatisticamente pelo teste não paramétrico de Kruskal-Wallis evidenciou diferenças para as variáveis: aparência, maciez e suculência sendo que as menores notas foram atribuídas à carne dos animais alimentados com o óleo de linhaça protegido e maiores notas foram obtidas para... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: The objective of this study was assess the meat quality, chemical and fatty acids composition of the loin (Longissimus thoracis) and chemical and fatty acids composition of the rump (Biceps femoris) from 35 Nellore young bulls, slaughtered weighing 532.2 ± 30.2 kg and 24 months of age. These animals were confined for 96 days and were fed with diets containing sugar cane (var. IAC86- 2480) and concentrate with different sources of oil, protected or not from ruminal degradation, all diets possessed the roughage:concentrate ratio of 40:60 in dry matter. After the fedlot period the animals were sent to a commercial abattoir, stunned and slaughtered, and soon after the carcass cooling, a section which included the 9th to 13th rib from Longissimus thoracis muscle and a standardized cut of Biceps femoris were removed, according to the establishment. The design was randomized blocks with five treatments and seven replicates and the averages were compared by orthogonal contrasts. The analysis of meat quality showed no significant differences in shear force (SF), pH, meat and fat color and cooking losses. The water holding capacity (WHC) showed differences and the linseed protected oil treatment showed higher values compared to the others (73.67% vs. 70.89%, respectively). The sensory evaluation done by trained tasting panel, statistically analyzed by nonparametric Kruskal-Wallis test, showed differences for the variables: appearance, tenderness and juiciness and the lowest scores were assigned to the meat of animals fed with linseed protected oil. The highest score was obtained from animals fed with soybean oil. No differences were found for loin cholesterol, and the values of this variable was lower for meat from animals fed soybean oil compared to other oils. We observed lower values for soybean protected oil... (Complete abstract click electronic access below)<br>Orientador: Alexandre Amstalden Moraes Sampaio<br>Coorientador: Wignez Henrique<br>Banca: Rymer Ramiz Tullio<br>Banca: Alexandre Rodrigo Mendes Fernandes<br>Banca: Flavio Dutra de Resende<br>Banca: Hirasilva Borba<br>Doutor

Conjugated Linoleic Acid (CLA) are a group of positional and geometric isomers of Linoleic Acid characterized by a carbon chain containing 18 carbon atoms and two double bonds, not in the classic position (cis), but conjugated from the carbons atoms 9, 10 or 11. Double bonds have different position in the carbon chain ([7,9], [8,10], [9,11], [10,12], [11,13] and [12,14]) and four different geometric distribution (cis/trans, trans/cis, cis/cis and trans/trans). In total 24 possible isomers are identify, but the two most present and often most identified are: C18:2cis9,trans11 (60-85% of the isomers identify in meat and >90% in milk) and C18:2trans10,cis12 isomers. Observing meat samples other isomers are commonly identified, as example, C18:2trans7,cis9 and C18:2trans11,cis13. In 1987, CLA have been discovered thanks to the research group of Dr. Pariza that studying some carcinogenic components in grilled meat, identify these molecules with anticancer activity, called Conjugated Linoleic Acid. After the discovery, they still receive many attention because of their biological activities and implication on human health. The biological effect are due to the separate actions of the main isomers (C18:2cis9,trans11 and C18:2trans10,cis12) and sometimes by the synergistic action of both. Also, minor isomers have biological effect, as examples, C18:2trans9,trans11 that inhibits platelet aggregation and has anti-proliferative effect and C18:2cis9,cis11 that showed anticancer effect. In animal model, CLA not only reduce initiation, promotion and progression steps of cancer development, but also reduce metastasis. Nevertheless, was show that CLA isomers are important because of they have effect on animal performance and the principal effects are: prevent chemically-induced tumors, protect against the catabolic effects of immune stimulation, improve feed efficiency, reduce excess body weight gain, reduce body fat, increase lean body mass and lower blood lipids. In human diet, the main sources of CLA are representing by ruminants products, in particular milk, dairy product and beef. The higher concentration of CLA in these products is linked to the presence of rumen that through microbial biohydrogenation (Butyrivibrio fibrisolvens) can transform Linoleic Acid to the major isomer C18:2cis9,trans11 (Rumenic Acid). Conjugated Linoleic Acid (CLA) can be analyze with different methods of lipid extraction and derivatization, but always after transformation in methyl ester derivatives of fatty acids (FAMEs) that is carried out in a simple reaction. This simple reaction becomes more complicated because of conjugated fatty acids are involved and the presence of conjugated double bond makes them unsuitable for the most common techniques employed for fatty acids analysis. The presence of double bonds may increase isomerization and epimerization of these bonds, increasing CLA with trans/trans configuration and reducing cis/trans or trans/cis configuration. For this reason is very important find a suitable method for lipid extraction (and the resulting determination of crude fat) and subsequently for the transformation in methyl ester derivatives of fatty acids (FAMEs). For this reason at the first part of my thesis was given a methodological approach in order to understand the differences between methods and which is the most suitable (Chapter 2 and Chapter 7). All the data used, belonging to a trial carried out at “Lucio Toniolo”, the Experimental Farm of the University of Padova in Legnaro (Padova, Italy). Animals used are a crossbreed between Belgian Blue bulls and Brown Swiss dairy cows fed with one of 3 experimental diets. Diets were composed by unifeed and differ depending on the rumen protected CLA supplementation (rpCLA), overall, three supplementation are available 0, 8 and 80 g/d/animal. The trial ended in March 2011 when animals were slaughtered outside the faculty in a slaughterhouse located in Pergine province of Trento (Trentino Alto Adige Region). Samples were collected and in particular three tissues were subjected to analysis for fatty acids profile and CLA content: muscle Longissimus Thoracis, Subcutaneous Fat and Liver. In the main Chapter (Chapter 2) tissues (Longissimus Thoracis, Subcutaneous Fat and Liver) were analyzed for determine fatty acids profile comparing three different methods of extraction (Folch (1957), Accelerated Solvent Extraction (ASE) and Jenkins (2010)) using as chromatography technique two dimensional GC (GC×GC). The purpose of this trial was identify among the different methods of extraction, one method that is able to identify CLA isomers without causing isomerization. Folch (1957) is one of the older and most used methods. It was born for analyze samples rich in phospholipids (as lipids of brain). It works at room temperature using a mixture of solvents composed by chloroform/methanol (2:1, v/v). Accelerated Solvent Extraction (ASE) was used with the purpose to compare a room temperature method with a method that works at high temperature and pressure (120°C and 20MPa) with the same mixture of solvents (chloroform/methanol, 2:1, v/v). This method, which have recently been introduced; reduce the use of solvent and saving time at work, giving results that were similar or better if compared with the conventional Folch (1957) extraction. On the contrary, it is expected to increase the isomerization of double bonds and the isomers with trans/trans configuration. The last method, Jenkins (2010), is a direct method, which reduces the length of the total procedure, saving time at work, reducing the sample amount, reducing the use of solvents, giving analysis less expensive and easier. The main characteristic is that lipid extraction step is avoided and fatty acids are extracted and trans-esterified in the same time. The statistical analysis was performed in four steps: resolution power and assessment of the number of undetected FA, study the main sources of variation, using Levene’s test explored the variances homogeneity for the main sources of variations and relationships between methods. The incidence of undetectable values on the total number of expected observation, which depend on the sensitivity of the method used, for liver, fat and muscle, ranged 0.04 to 0.08, 0.05 to 0.06, and 0.05 to 0.12, respectively, with incidences greater for the Jenkins method compared to the other two for liver and muscle samples but not for subcutaneous fat. In liver the highest incidence of null values with the Jenkins method was mainly observed for short chain FA (C8:0 and C10:0), whereas in the case of muscle the highest incidence of undetectable values was mainly observed for the C24:0, for two C20:1t unknown isomers, and for Ω3 (C20:3n3, C20:4n3, C22:5n6). Many sources of variation result high significant (P<0.001). Diet was significant in particular for the FA that are the main components of the supplementation (C18:0, C18:1cis9, C18:2cis9,trans11 and C18:2trans10,cis12). The results of the Levene’s test evidenced, except for diet, as the variances among levels within tissue, method or method×tissue were not homoscedastic for the large majority of the FA. The second part of the methodological approach is reported in Chapter 7 (Minor Chapter) and considers the effect of the chromatography technique on CLA isomers content. Despite the high resolution power of GC×GC this technique allows to identify all the FA and the CLA isomers recognized by internal standard. However, it is not able to identify the other isomers and for this reason is necessary to find a new method that allows a clear and complete identification of CLA. Silver Ion High Performance Liquid Chromotography (Ag+HPLC) is currently the most effective way to separate and quantitate individual isomers of CLA in beef. This part was performed with the contribution of the Leibniz Institute for Farm Animal Biology (Dummerstorf, Germany) and in particular the Muscle and Biology Growth Unit. Tissue analyze in this trial were Longissimus Thoracis, Subcutaneous Fat and Liver. Lipids were extracted using Folch (1957) and methylated using and acid-base catalysis. Data were analyzed considering as main sources of variation: diet, tissue and repetition. Tissue resulted always significant (P<0.001) with a tissue depending distribution of the isomers and a higher concentration in subcutaneous fat. Diet was significant for the main isomers (C18:2cis9,trans11 and C18:2trans10,cis12) because of constituents rpCLA supplementation. In the second part of my thesis are considered the effects that can modify FA profile, such as, breed, gender, diet, type of birth, age and tissue. Animals used belonging to four native alpine sheep breeds: Alpagota, Brogna, Foza and Lamon. All these breeds represent an important genetic resources and the purpose is created a program of conservation for increase the number of animals in these populations. For this reason Veneto Agricoltura created the experimental farm “Villiago” (Belluno province, Veneto Region, North Italy). Animals used for this research belongs to two flocks undergoing an in situ conservation program between “Lucio Toniolo” Experimental Farm of the University of Padova and the Experimental Farm of Veneto Agricoltura located in Villiago. In total 115 animals were used and reared in the period between December 2010 and July 2012. Animals are slaughter at different age and they are considered belonging to three different categories: 31 suckling lambs, 36 lambs, 24 heavy lambs and 24 ewes. The different trial were characterized by different diets: pasture (PAS), penned in the open barn and fed with hay, concentrate and supplemented with rumen protected Conjugated Linoleic Acid (rpCLA) product (CLA+) and penned in an open barn and fed with hay and concentrate (CLA-). In trials with “lambs” and “heavy lambs” animals were supplement with 8.0 g/d/animal of rpCLA. In “suckling lambs” and “ewes” animals were supplement with 4.0 g/d/animal of rpCLA and 12 g/d/animal of rpCLA, respectively. From the results, is possible observe that diet is highly significant (P<0.001) and in particular pasture. Fatty acids are statistically influenced by pasture and mainly fatty acids with odd chain and branched fatty acids (iso and anteiso) that tend to be lower in diet at pasture. The reason is that the diet can influence ruminal Ph and microorganisms that consequently change reactions and final products. Pasture is also important because it can influence the amount of long chain fatty acids (LC-PUFA), increasing Ω3 (respectively, PAS=2.70, CLA-=1.46 and CLA+=1.54), reducing Ω6 (respectively, PAS=3.76, CLA-=4.41 and CLA+=4.75) and Ω6/Ω3 ratio. CLA isomers content is higher in pasture than in diet with concentrate supplement with rpCLA (respectively, PAS=0.80, CLA-=0.56 and CLA+=0.71). In the other two trials characterized by CLA+ and CLA- diet was considered an important and significant effect. rpCLA supplementation reported significant effect (P<0.001 and P<0.01) for FA constituents of supplementation, such as C18:0 and C18:2trans10,cis12. In suckling lambs results were different from other trials, in particular for CLA isomers, such as, C18:2cis11,trans13 (P<0.01), C18:2cis11,cis13 (P<0.001) and C18:2cis9,cis11 (P<0.001). The reason is the different distribution is ewe’s milk that was used in suckling lambs diet and could have influence their fatty acids profile. Breed was not a significant effect, such as, gender and age at slaughter. Observing data about orthogonal contrast FA and CLA isomers distribution is tissue specific and there are many differences between lean tissues (muscle) and fat tissues. Liver has particular characteristics, in fact, its content of PUFA and particular Ω3 and CLA is higher than in the others tissues. Differences of this tissue are linked to its specific lipid composition and metabolic process which lead to the production and absorption of fatty acids. In Chapter 5 and Chapter 6 were evaluate effects that CLA supplementation can have on animal performance because of many research have been conduct in vitro, but other research are needed. In Chapter 5 was examined the effect of rpCLA supplementation in lactating ewes on their milk composition and Milk Coagulation Properties (MCPs) of sheep’s milk. Animal used in this trial are the same of the trial describe above and in particular of the trial call “suckling lambs” and “ewes”. This study allowed to know that rpCLA supplementation in sheep can change the composition and cheese-making properties of milk, as example, delaying gelation, slowing curd firming and accelerated syneresis and future studies are necessary to know the effect of CLA on cheese yield/ quality. rpCLA supplementation affect milk composition, reducing protein content, solid non-fat content, casein index and increasing SCS. rpCLA supplementation had negative effects on parameters of coagulation and curd firming. In Chapter 6 was evaluate the effect of breed and sex on growth rate, slaughter traits and meat quality traits of lambs of Alpagota, Brogna and Foza breeds. Animals used in this trial are the same of the trial describe above and in particular of the trial call “lambs”. These results are part of a bigger study which comprises also growth rate, slaughter traits and meat quality of the trial call “heavy lambs”, “suckling lambs” and “ewes”. Observing the results of this trial is possible obtain lamb carcasses and meat with valuable characteristics that can be exploited through typical products and food preparation in local markets and gastronomy, according to tradition. The valorisation of these productions can be an important tool for the in situ conservation of these breeds. As example, Slow Food organization has recognized “Agnello Alpagoto” (lambs of Alpagota breeds) as a Slow Food Presidium.<br>Dal 1987 anno in cui il Dott. Pariza e il suo gruppo di ricerca scoprirono i Coniugati dell’Acido Linoleico (CLA) molti sono stati gli studi che hanno cercato di definire le principali caratteristiche di queste molecole. Caratterizzati da un alto valore biologico gli furono attribuiti molti effetti benefici sulla salute umana, come l’effetto anticancerogeno, la riduzione del rischio di malattie cardiovascolari e la riduzione del rischio di sviluppo dell’aterosclerosi. In seguito gli fu attribuita anche importanza nel miglioramento delle performance animali, come l’aumento delle capacità di accrescimento, dell’efficienza alimentare e una riduzione della deposizione di grasso con conseguente aumento della massa magra. I Coniugati dell’Acido Linoleico (CLA) sono un gruppo d’isomeri geometrici e posizionali dell’Acido Linoleico caratterizzati da una catena di 18 atomi di carbonio contenente due doppi legami non in posizione classica (cis), ma coniugati dal carbonio 9, 10 o 11. I doppi legami possono presentare diversa disposizione spaziale dando origine a quattro diverse configurazioni: cis/trans, trans/cis, cis/cis e trans/trans. Secondo i carboni ai quali sono legati, possono avere diverse posizioni: ([7,9], [8,10], [9,11], [10,12], [11,13] e [12,14]) con un totale d’isomeri identificati pari a 24. I due più presenti e più identificati sono il C18:2cis9,trans11 (60-85% degli isomeri presenti nella carne e >90% nel latte) e il C18:2trans10,cis12. Altri isomeri molto presenti nella carne sono anche il C18:2trans7,cis9 e il C18:2trans11,cis13. Grazie alla capacità del rumine di produrre acidi grassi e in particolare CLA, si possono trovare soprattutto nei prodotti di origine animale (latte, prodotti lattiero caseari e carne). La presenza del doppio legame rende i CLA delle molecole complesse da identificare, perché può essere facilmente soggetto a fenomeni d’isomerizzazione o epimerizzazione che possono portare a un aumento delle forme di tipo trans/trans con conseguente riduzione delle forme cis/trans o trans/cis. Diversi studi hanno cercato di definire quale sia il metodo più adatto per l’estrazione del grasso (determinazione estratto etereo, EE) e per la successiva trasformazione in composti volatili, ovvero, esteri metilici degli acidi grassi (FAME). Per questo motivo parte della mia tesi è stata improntata su un approccio metodologico allo scopo di capire tra i tanti metodi quale fosse il più idoneo e che differenze i diversi metodi potessero avere. I dati contenuti nei contributi legati all’approccio metodologico sono stati raccolti da vitelloni maschi nati da un incrocio tra vacche da latte di razza Bruna e tori di razza Bianca Blu del Belgio. Questi animali sono stati allevati presso l’azienda sperimentale dell’Università degli Studi di Padova Lucio Toniolo. Durante tutta prova sono stati allevati in azienda e alimentati con una dieta a base di unifeed caratterizzata da tre diverse integrazioni di CLA rumino protetti (rpCLA): 0, 8 e 80 g di CLA al giorno per ogni animale. La prova è terminata con la macellazione avvenuta in un macello esterno all’Università situato a Pergine (Provincia di Trento, Trentino Alto Adige). I tessuti utilizzati per le analisi sono stati prelevati in macello ed in laboratorio di Qualità carne durante lo svolgimento delle analisi di qualità. I tessuti prelevati e studiati sono stati tre: muscolo Longissimus Thoracis, grasso sottocutaneo e fegato. Nel primo contributo (Chapter 2) i tessuti (Longissimus Thoracis, grasso sottocutaneo e fegato) sono stati analizzati allo scopo di determinare il profilo acidico, confrontando tre diversi metodi di estrazione del grasso (Folch (1957), Acellerated Solvent Extraction (ASE) e Jenkins (2010)) e utilizzando come tecnica cromatografica la Gas Cromatografia a due dimensioni (GCxGC). La scelta di eseguire un confronto metodologico è legata al fatto che secondo il metodo d’analisi utilizzato i risultati sono diversi. Di conseguenza, uno degli obiettivi era trovare un metodo che fosse in grado di salvaguardare i CLA senza provocare isomerizzazioni. A questo è dovuta la scelta del metodo Folch (1957), uno dei più antichi e più utilizzati in matrici di diversa natura. Nato per essere usato in campioni con grasso molto ricco di fosfolipidi (come il grasso presente nel cervello), lavora a temperatura ambiente utilizzando una miscela di solventi composta da cloroformio:metanolo (2:1, v/v). Il metodo Acellerated Solvent Extraction (ASE) è stato utilizzato allo scopo di confrontare una metodica che lavora con alte temperature e pressioni (120°C e 20 MPa) con una miscela di solventi identica a quella usata nel metodo Folch (1957) (cloroformio:metanolo (2:1, v/v)). Grazie alle caratteristiche positive il metodo ASE, negli ultimi anni si è molto diffuso. Esso è caratterizzato da una maggiore velocità d’estrazione, un ridotto utilizzo di solventi e una minore laboriosità da parte degli operatori. Si pensa che le condizioni (temperatura e pressione) a cui lo strumento lavora possano provocare isomerizzazioni incrementando gli isomeri con configurazione trans/trans. L’ultimo è un metodo diretto che in seguito ad una fase preparativa (di liofilizzazione del campione fatta con lo scopo di rimuovere l’acqua) permette di ottenere gli esteri metilici degli acidi grassi (FAME) da poter analizzare in GCxGC. Questo metodo richiede un’esterificazione di tipo acido-basico. Il lavoro è stato suddiviso in quattro passaggi in modo da: identificare il potere di risoluzione e l’incidenza di picchi non identificati, lo studio delle fonti di variazione, test di Levene per determinare l’omoscedasticità o eteroscedasticità delle varianze e infine degli studi per valutare la correlazione tra metodi. L’incidenza di valori non identificati è legata al numero di picchi osservati, che dipendono dalla sensibilità del metodo e dal tessuto analizzato: fegato, grasso e muscolo (da 0.04 a 0.08, da 0.05 a 0.06 e da 0.05 a 0.12, rispettivamente). La maggiore incidenza di valori nulli è stata osservata nel fegato e in particolare negli acidi grassi a corta/media catena (C8:0 e C10:0) e nel muscolo negli acidi grassi C24:0, C20:1t1t unknown isomers e nei PUFAn3 (C20:3n3, C20:4n3, C22:5n6) sempre con il metodo Jenkins (2010). Tra tutte le fonti di variazione analizzate lo scopo, era considerare le due principali che sono state molto significative (P<0.001) e sono rappresentate dal tessuto, dal metodo e dalla loro interazione. L’effetto della dieta è stato significativo per gli acidi grassi facenti parte dell’integrazione (C18:0, C18:1cis9 e C18:2trans10,cis12). Dai test di Levene è emerso che le varianze sono eteroscedastiche, tranne la dieta che è risultata, omoscedastica. Il passo successivo è stato considerare una tecnica cromatografica alternativa al GCxGC che fosse più specifica per lo studio degli isomeri dei CLA (Chapter 7) Nonostante, il GCxGC abbia un maggiore potere di risoluzione non è in grado di identificare tutti gli isomeri dei CLA, ma solo i due principali (C18:2cis9,trans11 e C18:2trans10,cis12). Per questo motivo sono presenti altre tecniche cromatografiche che permettono un’identificazione più precisa come la cromatografia liquida su colonna d’argento (Ag+HPLC). Il lavoro è stato svolto in collaborazione con il Leibniz Insitute for Farm Animal Biology (Dummerstorf, Germany) e in particolare l’unità di Muscle and Biology Growth. L’obiettivo in questo caso era identificare il maggior numero d’isomeri dei CLA presenti nel campione. I tessuti analizzati erano: muscolo (Longissimus Thoracis), grasso sottocutaneo e fegato. Il grasso (estratto etereo, EE) è stato ottenuto con il metodo Folch (1957) cui è seguita poi un’esterificazione acido-basica. Le analisi statistiche sono state eseguite considerando gli effetti di dieta, tessuto e ripetizione sulla distribuzione degli isomeri. La prima cosa che differenzia questa metodica dal GCxGC è il numero di picchi identificati che sono molto più elevati (13 isomeri). Questo tipo di tecnica premette un’identificazione precisa di molti isomeri dei CLA con un unico problema nell’identificazione dei picchi che si trovano nella regione dei cis/cis (l’ultima a comparire nel cromatogramma), per la quale è difficile identificare l’isomero C18:2cis9,cis11. Dai risultati è emerso che il tessuto è molto significativo (P<0.001) e la distribuzione degli isomeri è tessuto dipendente, con una concentrazione più alta nel grasso. L’effetto della dieta, in particolare quella con integrazione 8.0 g di CLA al giorno, è risultato significativo per gli isomeri principali (C18:2cis9,trans11 e C18:2trans10,cis12). Nella seconda parte della tesi sono state prese in considerazione le fonti di variazione del profilo acidico, come razza, sesso, dieta, ordine di parto, età e tessuto (Chapter 3 e Chapter 4). Gli animali usati in queste prove appartengono a quattro razze ovine Venete: Alpagota, Brogna, Foza e Lamon che presentano diversa condizione di criticità; valutata in base al numero di capi allevati, di maschi arieti utilizzati per gli accoppiamenti e di allevamenti. Al fine di salvaguardare e recuperare queste razze, Veneto Agricoltura, su indicazione della Regione Veneto ha creato l’azienda sperimentale di Villiago, un importante centro di conservazione di queste razze, che mira a produrre nuovi giovani riproduttori (agnelle e montoni) per gli allevatori interessati e a organizzare azioni a sostegno dello sviluppo dell’allevamento. I dati riportati in questa tesi coinvolgono animali che sono stati allevati seguendo un piano di conservazione in-situ che prevedeva la collaborazione tra l’azienda sperimentale di Veneto Agricoltura “Villiago” e l’azienda sperimentale dell’Università di Padova “Lucio Toniolo”. In totale gli animali utilizzati sono stati 115 e sono stati allevati tra Dicembre 2010 e Luglio 2012. Macellati a età diverse, erano considerati appartenenti a tre categorie: 31 agnelli da latte, 36 agnelli leggeri, 24 agnelloni pesanti e 24 pecore. Le tre prove (agnello leggero, agnellone pesante, agnello da latte-pecora) erano caratterizzate da diete diverse. Nella prima prova “agnello leggero” le diete utilizzate erano: pascolo (PAS), fieno e concentrati con integrazione CLA rumino protetti (rpCLA, 8.0 g/d/animale) (CLA+) e dieta con fieno e concentrati senza integrazione di rpCLA (CLA-). Nelle prove “agnellone pesante” e “agnello da latte-pecora” le diete erano composte da concentrati con integrazione rpCLA (8.0 g/d/animale per gli agnelloni pesanti, 12 g/d/animale per le pecore e 4.0 g/d/animale per gli agnelli da latte) (CLA+) e concentrati senza integrazione rpCLA (CLA-). Dai risultati è emerso che diversi fattori possono influenzare il profilo acidico e in particolare dalla prima prova che la dieta può avere un ruolo molto importante (P<0.001). La presenza del pascolo è risultata significativa per molti acidi grassi a catena dispari e catena ramificata (forme iso e anteiso) che tendono a essere meno elevati al pascolo. Il motivo è che con la dieta è possibile alterate il PH ruminale e la flora microbica in esso presente modificando così anche gli acidi grassi che questa può produrre. Il ruolo del pascolo è importante anche per quanto riguarda gli acidi grassi a lunga catena (LC-PUFA). Il pascolo può aumentare gli Ω3 (rispettivamente, PAS=2.70, CLA-=1.46 e CLA+=1.54) riducendo gli Ω6 (rispettivamente, PAS =3.76, CLA-=4.41 e CLA+=4.75) e di conseguenze anche il rapporto Ω6/Ω3. Rispetto alla dieta a base di concentrati con integrazione (CLA+) il pascolo ha portato a un aumento dei CLA (rispettivamente, PAS=0.80, CLA-=0.56 e CLA+=0.71). La dieta si conferma significativa, anche nelle prove “agnellone pesante” e “agnello da latte-pecora” con il confronto tra le diete a base di concentrati (CLA- e CLA+). L’integrazione di rpCLA nella dieta è risultata significativa (P<0.001 e P<0.01) per gli acidi grassi considerati i suoi principali costituenti, per cui il C18:0 e il C18:2trans10,cis12. Gli agnelli da latte hanno presentato dei risultati diversi dagli altri animali, soprattutto in relazione ai CLA. Sono risultati significativi gli isomeri C18:2cis11,trans13 (P<0.01), C18:2cis11,cis13 (P<0.001) e C18:2cis9,cis11 (P<0.001). Il motivo di questa diversa distribuzione è stato attribuito al ruolo del latte di pecora, usato come alimento per gli agnelli e che può aver influito sulla composizione acidica dei loro tessuti. La razza in tutte le prove è stata un effetto che non ha portato a delle differenze significative dal punto di vista statistico, come anche il sesso e l’età di macellazione. Dai contrasti effettuati tra tessuti, è emerso, com’era stato osservato per i vitelloni, che la distribuzione degli acidi grassi è tessuto specifica e può cambiare secondo il tessuto analizzato. Differenze sono evidenti in tutti i tessuti ma in particolare tra i magri e quelli grassi. Il fegato in tutte e prove è stato il tessuto che presenta delle caratteristiche particolari perché caratterizzato da una maggiore quantità di acidi grassi polinsaturi (PUFA) e in particolare da una maggiore quantità di Ω3 e CLA. La diversa composizione di questo tessuto è legata alla composizione in termini di tipologia di lipidi che lo costituiscono e dai processi metabolici ai quali quest’organo partecipa che portano alla produzione, oppure all’assorbimento degli acidi grassi assunti con la dieta (Chapter 3 e Chapter 4). Sempre in animali appartenenti alle razze (Alpagota, Brogna, Foza e Lamon) sono state prese in esame le performance animali ed i vari fattori che le possono influenzare. E’ noto che l’utilizzo di rpCLA può provocare un incremento dell’efficienza alimentare favorendo l’aumento della massa magra con la successiva riduzione di quella grassa. Negli animali in lattazione (vacche, pecore e capre) è dimostrato che l’integrazione di rpCLA può provocare una riduzione nel contenuto di grasso presente nel latte. Nella mia tesi è stato considerato l’effetto della dieta sul latte di pecore (Chapter 5) al fine così di valutare quelle che vengono definite proprietà di qualità del latte espresse in termini di composizione chimica e proprietà di coagulazione (MCPs). Gli animali utilizzati in questa prova sono i medesimi utilizzati per lo studio dei profili acidici delle carni. Dal punto di vista della qualità della carne alla macellazione per cercare di definire se dieta, sesso e razza potessero influire sulle rese di macellazione (Chapter 6). Gli animali usati in questa prova sono i medesimi della prova vista in precedenza, ovvero la prova “agnello leggero”. I risultati ottenuti in questo lavoro sono dei risultati che comprendono solo parte del lavoro che invece comprenderà anche le prove “agnellone pesante” e “agnello-pecora”. Da questo lavoro quello che si vuole esprimere è che gli animali appartenenti a queste razze sono in grado di produrre delle carcasse che presentano caratteristiche ottimali e idonee al mercato alimentare. La caratteristica in più che queste presentano è che le modalità di allevamento, ben lontane da quelle di tipo industriale o più specializzato ci permettono di ottenere un prodotto allevato nel rispetto delle tradizioni e che può far parte di presidi ampiamente riconosciuti come l’Agnello Alpagoto noto per essere un presidio Slow Food.

Foram utilizados 24 cordeiros cruzados Ile de France, com peso médio inicial de 22,27 ± 1,85 kg e, aproximadamente, 80 dias de idade, suplementados com os níveis 0 (controle); 0,3; 0,9 e 2,7 g/kg de MS de produto enzimático comercial, contendo amilase, celulase, fitase, xilanase, betaglucanase, pectinase e protease, adicionado no momento da mistura do concentrado. O desempenho animal não foi afetado pela adição das enzimas, com médias de 37,3 ± 4,3 kg; 1,182 ± 0,153 kg/dia; 0,356 ± 0,077 kg/dia e 3,3 ± 0,3 para o PVF, IMS, GPD e CA, respectivamente. Para a digestibilidade da MS, FDN, FDA, PB, EE, NDT e amido, as médias foram, respectivamente, 80,55; 60,14; 58,80; 81,55; 52,02; 83,16 e 98,20%. A Digestibilidade da FDN apresentou uma tendência de aumento linear conforme o acréscimo do nível de enzima, com uma melhora de 11% para o último nível, em relação ao controle. As demais variáveis não foram alteradas. As concentrações de fósforo e glicose plasmáticos não foram alteradas pela enzima. O protozoário do gênero Entodinium sp. representou mais de 95% do total de ciliados para todos os tratamentos avaliados, e os dados se ajustaram ao efeito quadrático, com o nível de 2,18 kg de enzima/kg de MS proporcionando maior crescimento destes. Para o pH ruminal ao abate, não houve influência das enzimas. Os rendimentos de carcaça quente e fria apresentaram uma queda até os níveis de 1,61 e 1,55 g de enzima/kg de MS, respectivamente, sendo que, após estes valores, os rendimentos se aproximaram novamente do controle. A adição de níveis crescentes de enzimas diminuiu a perda de água por exsudação, mas não afetou a perda por cocção e a maciez da carne de cordeiros. Portanto, apesar da melhora em alguns parâmetros, o desempenho dos animais, bem como as características de carcaça e da carne, não foram afetados pela adição das enzimas, sendo que, para ovinos, o complexo enzimático avaliado não é eficaz sob as mesmas condições experimentais.<br>Twenty-four crossbred lambs Ile de France, with initial average body weight of 22,7 ± 1,85 kg and age of 80 days, were supplemented with 0 (control treatment); 0,3; 0,9 e 2,7 g/kg DM levels of enzymatic commercial product, with amylase, cellulose, phytase, xylanase, glucanase, pectinase e protease, added at the moment of concentrate mixing. Performance was not affected by enzyme complex supplement,, with averages of 37,3 ± 4,3 kg; 1,182 ± 0,153kg/day, 0,356 ± 0.077 kg/day and 3,3 ± 0,3 for FLW, DMI, ADG and FC, respectively. For DM, NDF, ADF, CP, EE, TDN and starch, the averages were, respectively, 80,55;60,14; 58,80; 81,55; 52,02; 83,16 and 98,20%. There was observed a tendency to FDN digestibility with linear increasing as the enzyme levels increased, with an improvement of 11% for the last level, compared to control diet. All the others variables were not changed. Glucose and phosphorus concentrations were not affected by the enzyme complex. The Entodinium sp. protozoa represented more than 95% of the total ciliated protozoa for all treatments studied and the data were adjusted by the quadratic effect, with the level of 2,18 kg of enzyme/kg of DM showing a better growing of those. Ruminal pH at the slaughter, was not affected by enzymes. Hot dressing percentage and cold dressing percentage decreased until levels of 1,61 and 1,55 g of enzyme/kg of DM, respectively, even when after these data, dressing percentage went back closely to the control treatment. The increasing levels addition of enzyme decreased drip loss, but did not affect the cocking loss and tenderness of lambs meat. Despite the improvement of some parameters, as well as performance, meat and carcass characteristics, were not affect by the enzymes, suggesting that enzyme complex analyzed was not efficient at the same experimental conditions for sheep.

The potential of red meat, particularly that produced from grass-fed animals, to contribute to dietary intakes of long chain (LC) n-3 PUF A has become the focus of recent research. However, there remains little information on precise quantities of these fatty acids found in commercially produced red meat, the use of grass finishing diets by producers, or the ability of red meat produced from grass feeding regimes to contribute to LCn-3 PUF A intakes or status in consumers, especially in the UK and Ireland. Extensive fatty acid data were measured for beef and lamb produced in Northern Ireland over a 12 month period and the frequency of a grass diet being offered to animals before slaughter was determined by a survey carried out among a sample of beef and lamb producers. To investigate the effect of consumption of red meat produced from grass-fed animals on LCn-3 PUF A status, a human intervention study was carried out among healthy subjects. In addition, the potential for red meat produced from grass-fed animals to contribute to LCn-3 PUF A intakes in the Irish population was hypothetically assessed based on current intakes of meat. Beef and lamb were reported to contain concentrations ofLCn-3 PUFA similar to levels achieved with grass feeding by other studies. The season of slaughter and, to a lesser extent, the reported finishing diet of the animal were found to cause variation in concentrations ofLCn-3 PUFA and conjugated linoleic acids (CLA) found in beef and lamb. The survey revealed that grass finishing diets are commonly offered to animals by producers of beef and lamb, but the frequency of these diets also varied by season. In the human intervention study, consumption of red meat from grass-fed animals was associated with significantly increased plasma and platelet LCn-3 PUF A status among healthy subjects. Based on red meat consumed in the Irish diet being from grass-fed animals, the provision of red meat to LCn-3 PUF A intakes would be modestly increased than if meat consumed were from concentrate-fed animals. In conclusion, the production of red meat from grass-fed animals will contribute to increased LCn-3 PUF A intakes and status among Irish consumers, where red meat is habitually consumed. Further research is warranted to investigate the opportunity to further enhance concentrations ofLCn-3 PUF A within red meat by increased use of grass feeding regimes in beef and lamb production.

Made available in DSpace on 2014-06-11T19:33:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-12-13Bitstream added on 2014-06-13T19:23:42Z : No. of bitstreams: 1 oliveira_f_dr_botfmvz.pdf: 259669 bytes, checksum: 0bfebd210e9bcf4063bab51c4e20b6a4 (MD5)<br>objetivo deste estudo foi avaliar as características da carcaça de cordeiros confinados e alimentados com dietas contendo três níveis de substituição de farelo de soja por soja grão e suplementação com vitamina E (com ou sem suplementação). Foram utilizados 30 cordeiros machos não castrados da raça Ile de France puros, com peso vivo médio inicial de 18 kg, aleatoriamente sorteados entre os níveis de inclusão de grãos de soja (0, 7 e 14%) e suplementação com vitamina E. A dieta experimental foi constituída de feno de Tifton 85, fubá de milho, farelo de soja, grão de soja moído e suplemento mineral comercial para atender as exigências nutricionais de 250 g/dia. Os cordeiros ao atingirem o peso aproximado de 38 kg, foram abatidos em frigorífico comercial após jejum alimentar de 18 horas. Foram avaliados o consumo de matéria seca (CMS), ganho médio diário (GMD), pesos ao abate (PA), pesos de carcaça quente (PCQ), pesos de carcaça fria (PCF), rendimento de carcaça quente (RCQ), rendimento de carcaça fria (RCF), índice de quebra por resfriamento (IQR). A dieta teve influência significativa (P<0,05) sobre o CMS, GMD, PA, PCQ e PCF, sendo que o nível de 0% de inclusão de grãos de soja na dieta apresentou as maiores médias. Não houve influência significativa (P>0,05) para os rendimentos dos cortes. Os diferentes tecidos da perna não foram afetados (P>0,05) pela dieta ou suplementação com vitamina E. A suplementação com vitamina E não altera os parâmetros quantitativos da carcaça. a inclusão de grãos de soja em até 14% na matéria seca da ração é recomendada, considerando o seu custo em relação aos demais ingredientes<br>The objective of this study was to evaluated the carcaterísticas carcass feedlot lambs fed diets containing three levels of replacement of soybean meal by soybean grain and vitamin E supplementation (presence or absence). We used 30 male lambs castrated Ile de France, with average weight of 18 kg were randomly drawn between levels of inclusion of soybean (0, 7 and 14%) and supplementation with vitamin E. The experimental diet consisted of Bermuda grass hay 85, corn meal, soybean meal, ground soybean and commercial mineral meet the nutritional requirements of 250 g / day. Lambs to reach the approximate weight of 38 kg, were slaughtered in commercial refrigerator after a fasting period of 18 hours. Evaluated the dry matter intake (DMI), average daily gain (ADG), the slaughter weight (SW), hot carcass weight (HCW), cold carcass weight (CCW), carcass yield (HCY), cold carcass yield (CCY), index chilling losses (ICL). The diet had a significant influence (P <0.05) over the SW, HCW and CCW, and the 0% level of inclusion of soybean in the diet showed the highest. The different tissues of the leg were not affected (P> 0.05) by diet or supplementation with vitamin E. The vitamin E supplementation does not alter the quantitative parameters of the carcass. The inclusion of soybeans in up to 14% in the dry matter is recommended, considering its cost in relation to other ingredients

Orientador: André Mendes Jorge<br>Banca: Simone Fernandes<br>Banca: Paulo de Lima Meirelles<br>Banca: Cristiana Andrighetto<br>Banca: Juliana dos Santos<br>Resumo: objetivo deste estudo foi avaliar as características da carcaça de cordeiros confinados e alimentados com dietas contendo três níveis de substituição de farelo de soja por soja grão e suplementação com vitamina E (com ou sem suplementação). Foram utilizados 30 cordeiros machos não castrados da raça Ile de France puros, com peso vivo médio inicial de 18 kg, aleatoriamente sorteados entre os níveis de inclusão de grãos de soja (0, 7 e 14%) e suplementação com vitamina E. A dieta experimental foi constituída de feno de Tifton 85, fubá de milho, farelo de soja, grão de soja moído e suplemento mineral comercial para atender as exigências nutricionais de 250 g/dia. Os cordeiros ao atingirem o peso aproximado de 38 kg, foram abatidos em frigorífico comercial após jejum alimentar de 18 horas. Foram avaliados o consumo de matéria seca (CMS), ganho médio diário (GMD), pesos ao abate (PA), pesos de carcaça quente (PCQ), pesos de carcaça fria (PCF), rendimento de carcaça quente (RCQ), rendimento de carcaça fria (RCF), índice de quebra por resfriamento (IQR). A dieta teve influência significativa (P<0,05) sobre o CMS, GMD, PA, PCQ e PCF, sendo que o nível de 0% de inclusão de grãos de soja na dieta apresentou as maiores médias. Não houve influência significativa (P>0,05) para os rendimentos dos cortes. Os diferentes tecidos da perna não foram afetados (P>0,05) pela dieta ou suplementação com vitamina E. A suplementação com vitamina E não altera os parâmetros quantitativos da carcaça. a inclusão de grãos de soja em até 14% na matéria seca da ração é recomendada, considerando o seu custo em relação aos demais ingredientes<br>Abstract: The objective of this study was to evaluated the carcaterísticas carcass feedlot lambs fed diets containing three levels of replacement of soybean meal by soybean grain and vitamin E supplementation (presence or absence). We used 30 male lambs castrated Ile de France, with average weight of 18 kg were randomly drawn between levels of inclusion of soybean (0, 7 and 14%) and supplementation with vitamin E. The experimental diet consisted of Bermuda grass hay 85, corn meal, soybean meal, ground soybean and commercial mineral meet the nutritional requirements of 250 g / day. Lambs to reach the approximate weight of 38 kg, were slaughtered in commercial refrigerator after a fasting period of 18 hours. Evaluated the dry matter intake (DMI), average daily gain (ADG), the slaughter weight (SW), hot carcass weight (HCW), cold carcass weight (CCW), carcass yield (HCY), cold carcass yield (CCY), index chilling losses (ICL). The diet had a significant influence (P <0.05) over the SW, HCW and CCW, and the 0% level of inclusion of soybean in the diet showed the highest. The different tissues of the leg were not affected (P> 0.05) by diet or supplementation with vitamin E. The vitamin E supplementation does not alter the quantitative parameters of the carcass. The inclusion of soybeans in up to 14% in the dry matter is recommended, considering its cost in relation to other ingredients<br>Doutor

Na intenção de avaliar o efeito da suplementação protéica, uso de subprodutos agroindustriais e o processamento de milho, foram conduzidos quatro experimentos. No experimento I, avaliou-se formas de processamento de milho (milho moído, M; e resíduo de pipoca doce, P) e fontes protéicas (farelo de soja, FS; uréia, U; ou farinha de peixe, FP), combinando-os para formar quatro tratamentos: MFS (M + FS); PFS (P + FS); PFP (P + FS + FP); PU (P + U). Comparado ao milho moído (MFS), o resíduo de pipoca doce (PFS) diminuiu os teores de gordura e proteína no leite. Em relação às fontes protéicas (PFS x PFP x PU), observou-se que a maior produção leiteira foi obtida no tratamento PFS. A farinha de peixe (PFP) levou ao menor teor de gordura no leite, mas aumentou o teor protéico no leite. No experimento II, avaliou-se os efeitos da inclusão de três teores (0,15 e 30% da MS) de farelo de algodão (FA) em substituição ao farelo de soja na dieta. O consumo de MS não foi afetado pelos tratamentos, contudo a inclusão de FA levou a efeitos lineares negativos sobre a produção de leite e teor e produção de proteína e efeitos lineares positivos sobre o teor e produção de gordura no leite. No experimento III, comparou-se os efeitos de uma dieta basal com 16% de PB contra duas outras com 17,5% de PB, sendo esses incrementos obtidos através da adição de uréia (U-17,5, resultando em aumento de proteína degradável no rúmen, PDR) ou farelo de soja e de algodão (FSFA-17,5, resultando em aumento de proteína metabolizável, PM). O aumento do teor de PDR (U-17,5) tendeu a aumentar o consumo de MS em relação à dieta basal. A produção de leite elevou-se com o aumento de PM (FSFA-17,5), não ocorrendo o mesmo com o aumento de PDR (U-17,5). O teor e a produção de proteína no leite também elevou-se com o fornecimento extra de PM. Concluiu-se que a elevação do teor de PM para valores acima das recomendações propostas pelo National Research Council - NRC (2001) para vacas produzindo ao redor de 29 kg/d melhorou as produções de leite e de proteína no leite. O experimento IV consistiu de dois ensaios. No primeiro, os tratamentos continham 0 (RUC-0), 10 (RUC-10) ou 20% (RUC-20) de resíduo úmido de cervejaria (RUC). Todas as dietas continham 1% de uréia. Um quarto tratamento isoprotéico, com 2% de uréia substituindo parcialmente o farelo de soja, sem RUC, foi utilizado. O consumo de MS não foi afetado. A produção de leite e o teor e produção de proteína no leite aumentaram com a inclusão de RUC e foram prejudicados com o fornecimento de 2% de uréia. No ensaio 2, foram comparados o RUC fresco com o RUC ensilado com milho moído. Ambos os tratamentos eram isoprotéicos e continham proporções semelhantes de milho moído e RUC. O consumo de MS, produção de leite e os teores e produções de gordura e proteína no leite não foram afetados pelos tratamentos.<br>Four studies were conducted to compare protein sources and content, corn processing method and a fibrous by-product for lactating dairy cows. Study 1: corn processing methods (fine ground, M; and popped, P) and protein sources (soybean meal, FS; urea, U; or fishmeal, FP) were compared in 4 treatments: MFS (M + FS); PFS (P + FS); PFP (P + FS + FP); PU (P + U). Compared to fine ground corn (MFS), popped corn (PFS) decreased milk fat and protein content. The 3 protein sources comparisons (PFS x PFP x PU) showed that milk yield was higher for PFS. Feeding fishmeal (PFP) decreased milk fat content, but increased milk protein content. Study 2: the cottonseed meal content in the diet (0, 15 and 30% of DM) in replacement to soybean meal were compared. Dry matter intake was not affected by treatments, but cottonseed meal supplementation had a negative linear effect on milk yield and on milk protein content and yield. Increasing cottonseed meal had a positive linear effect on milk fat content and yield. Study3: basal diet (16% CP) was compared to two diets with 17.5% CP, where crude protein content of diets were increased by feeding extra urea (U-17.5, resulting in increased rumen degradable protein content, RDP) or extra soybean and cottonseed meal (FSFA-17.5, resulting in increased metabolizable protein content, MP). Extra RDP (U-17.5) tended to increase DMI compared to basal diet. Milk yield were increased by extra MP (FSFA-17.5) but not by extra RDP (U-17.5). Milk protein content and yield were also increased by feeding extra MP. In conclusion, increasing diet MP content above National Research Council - NRC (2001) recommendations for cows producing around 29 kg/d improved milk and milk protein yields. Study 4: two trials were conducted. In trial 1, treatments were 0 (RUC-0), 10 (RUC-10) or 20% (RUC-20) wet brewers grains inclusion in diet dry matter. All 3 diets contained 1% urea on a DM basis. A fourth isonitrogenous diet, with additional urea (2% of diet DM) in partial replacement of soybean meal, without brewers grains, was compared to. Dry matter intake were not different. Milk yields and milk protein contents and yields were increased by feeding wet brewers grains and decreased by feeding 2% urea. In trial 2, weekly received fresh wet brewers grains versus wet brewers grains ensiled with ground corn were compared. Both treatments were isonitrogenous diets and contained the same proportions of ground corn and wet brewers grains on a dry matter basis. Dry matter intake, milk yield, milk fat content and yield and protein content and yield were not different.

La composition du lait en acides gras (AG) chez la vache laitière est la résultante du métabolisme lipidique au niveau du rumen et au niveau de la glande mammaire. Dans le cadre du renouvellement des systèmes d’unités d’alimentation INRA, l’objectif de ce travail est de prédire par une approche quantitative utilisant la méta-analyse de bases de données, les flux duodénaux d’AG chez les ruminants, le transfert des AG de l’intestin à la glande mammaire, et les flux d’AG sécrétés dans le lait.Des équations de prédiction des flux duodénaux et absorbés des AG saturés, des AG impairs et ramifiés, et d’un grand nombre d’isomères des AG insaturés ont été obtenues en intégrant les effets de facteurs expérimentaux tels que la nature du fourrage, le pourcentage de concentré, la supplémentation en huiles, graines végétales, et en produits marins, et leurs interactions. Ces équations sont fonction des AG ingérés et des facteurs interférents (mode de conservation et familles botaniques des fourrages, composition du régime alimentaire, caractéristiques des animaux).Pour le transfert des AG du duodénum à la glande mammaire, les équations privilégient comme prédicteur leur flux duodénal respectif, mais utilisent aussi des paramètres digestifs ruminaux (pH, acétate, butyrate) ou des caractéristiques des rations pour les AG impairs et ramifiés, ou les AG synthétisés de novo (C4:0 à C14:0).La validation de ces modèles a été faite à partir d’une base de données externe qui a permis de coupler les deux modèles et d’évaluer leur précision. Finalement, nous proposons des équations de prédiction des AG spécifiques ainsi que des groupes d’AG présentant un intérêt nutritionnel et qui peuvent fournir une approche aux systèmes d'unités d'alimentation pour prédire leurs réponses à différents types de rations<br>Milk fatty acids (FA) composition in dairy cows results from lipid metabolism in rumen and mammary gland. In the context of renewing the INRA feed unit system, the objective of this work is to predict, by a quantitative approach using metaanalysis, duodenal flows of FA in ruminants, FA transfer from the intestine to the mammary gland, and the secreted FA flows in the milk. Predictive equations for duodenal and absorbed saturated FA, odd and branched FA, and a large number of unsaturated FA isomers were obtained by integrating the effects of experimental factors such as the nature of the forage, the concentrate percentage, supplementation with oleaginous oils and seeds, and marine products, and their interactions.These equations are function of ingested FA and their interfering factors (forage conservation mode and botanical family, diet composition, animal factors).For the transfer of FA from duodenum to the mammary gland, the equations favor the prediction of their respective duodenal flows, but they also use ruminal digestive parameters (pH, acetate, butyrate) or dietary characteristics for odd and branched FA, or de novo synthesized FA (C4 :0 to C14 :0).Models validation was done with an external database, which allowed coupling the two models and evaluate their accuracy. Finally, we propose predictive equations for specific FA as well as FA groups of nutritional interest that can provide an approach to the INRA feed unit system to predict their milk yield responses according to different types of rations

Made available in DSpace on 2014-06-11T19:33:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-24Bitstream added on 2014-06-13T18:45:19Z : No. of bitstreams: 1 oliveira_ea_dr_jabo.pdf: 1159929 bytes, checksum: 57312724924758d48f60ea911e40e1de (MD5)<br>Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)<br>Objetivou-se com este estudo avaliar as características qualitativas da carne, a composição química e de ácidos graxos dos cortes do contrafilé (Longissimus thoracis) e a composição química e de ácidos graxos da picanha (Biceps femoris) de 35 tourinhos da raça Nelore abatidos com peso de 532,17 ± 30,2 kg e 24 meses de idade. Estes animais foram confinados por 96 dias e receberam dietas contendo cana-de-açúcar (var. IAC86-2480) e concentrado com diferentes fontes de óleos protegidos ou não da degradação ruminal; todas as dietas possuíam a relação volumoso:concentrado de 40:60 na matéria seca. Após o período de engorda os animais foram enviados a um frigorífico comercial, abatidos e depois do resfriamento das carcaças, foi retirada uma seção que compreendia da 9a à 13a costelas do músculo Longissimus thoracis e uma peça padronizada, de acordo com o estabelecimento, do músculo Biceps femoris e trazidas ao laboratório para posteriores análises. O delineamento utilizado foi em blocos casualizados com 5 tratamentos e 7 repetições, sendo as médias comparadas por contrastes ortogonais. As análises da qualidade da carne não mostraram diferenças significativas para força de cisalhamento, pH, cor da carne, da gordura e perdas no cozimento. A capacidade de retenção de água evidenciou diferenças, sendo que, o óleo de linhaça protegido foi o tratamento que apresentou os maiores valores em relação aos demais (73,67 vs. 70,89%, respectivamente). A avaliação sensorial feita por painel de degustação treinado, analisadas estatisticamente pelo teste não paramétrico de Kruskal-Wallis evidenciou diferenças para as variáveis: aparência, maciez e suculência sendo que as menores notas foram atribuídas à carne dos animais alimentados com o óleo de linhaça protegido e maiores notas foram obtidas para...<br>The objective of this study was assess the meat quality, chemical and fatty acids composition of the loin (Longissimus thoracis) and chemical and fatty acids composition of the rump (Biceps femoris) from 35 Nellore young bulls, slaughtered weighing 532.2 ± 30.2 kg and 24 months of age. These animals were confined for 96 days and were fed with diets containing sugar cane (var. IAC86- 2480) and concentrate with different sources of oil, protected or not from ruminal degradation, all diets possessed the roughage:concentrate ratio of 40:60 in dry matter. After the fedlot period the animals were sent to a commercial abattoir, stunned and slaughtered, and soon after the carcass cooling, a section which included the 9th to 13th rib from Longissimus thoracis muscle and a standardized cut of Biceps femoris were removed, according to the establishment. The design was randomized blocks with five treatments and seven replicates and the averages were compared by orthogonal contrasts. The analysis of meat quality showed no significant differences in shear force (SF), pH, meat and fat color and cooking losses. The water holding capacity (WHC) showed differences and the linseed protected oil treatment showed higher values compared to the others (73.67% vs. 70.89%, respectively). The sensory evaluation done by trained tasting panel, statistically analyzed by nonparametric Kruskal-Wallis test, showed differences for the variables: appearance, tenderness and juiciness and the lowest scores were assigned to the meat of animals fed with linseed protected oil. The highest score was obtained from animals fed with soybean oil. No differences were found for loin cholesterol, and the values of this variable was lower for meat from animals fed soybean oil compared to other oils. We observed lower values for soybean protected oil... (Complete abstract click electronic access below)

Submitted by Ismael de Castro Pereira null (ismael_pepe@hotmail.com) on 2016-07-14T12:02:50Z No. of bitstreams: 1 Dissertação Ismael C. Pereira.pdf: 999527 bytes, checksum: 659b99bf13f31aff35209d2f1c4f2380 (MD5)<br>Rejected by Ana Paula Grisoto (grisotoana@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: A data informada na capa do trabalho está diferente da data de defesa. Corrija esta informação no arquivo PDF e realize uma nova submissão contendo o arquivo correto. Agradecemos a compreensão. on 2016-07-14T17:49:56Z (GMT)<br>Submitted by Ismael de Castro Pereira null (ismael_pepe@hotmail.com) on 2016-07-14T18:06:25Z No. of bitstreams: 1 Dissertação Ismael C. Pereira.pdf: 954667 bytes, checksum: 37ebeb6c315f8a5dff36a212d3369bca (MD5)<br>Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-07-14T18:15:12Z (GMT) No. of bitstreams: 1 pereira_ic_me_bot.pdf: 954667 bytes, checksum: 37ebeb6c315f8a5dff36a212d3369bca (MD5)<br>Made available in DSpace on 2016-07-14T18:15:12Z (GMT). No. of bitstreams: 1 pereira_ic_me_bot.pdf: 954667 bytes, checksum: 37ebeb6c315f8a5dff36a212d3369bca (MD5) Previous issue date: 2016-06-17<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>O presente estudo teve o objetivo de avaliar o impacto da flutuação natural da ingestão de massa seca no desempenho, características de carcaça, comportamento ingestivo, perfil metabólico sanguíneo e aspectos morfofisiológicos ruminais de bovinos alimentados com dietas de alta inclusão de concentrado, por meio de estudo meta-analítico. Os experimentos contidos na meta-análise utilizaram animais com grupamento genético similar ao utilizado em confinamentos comerciais brasileiros. A meta-análise teve como base de dados os resultados de dez experimentos conduzidos no Confinamento Experimental da Faculdade de Medicina Veterinária e Zootecnia da UNESP, em Botucatu, entre os anos de 2006 e 2015. Os dados foram coletados a partir 838 bovinos, divididos em 238 baias, consideradas as unidades experimentais para o estudo. Os valores de flutuação de ingestão de massa seca na baia foram calculados pela diferença da ingestão de massa seca entre dois dias consecutivos e dividido pelo dia anterior para encontrar o valor em porcentagem. Com base na mediana geral de 5,62%, os animais foram divididos em dois grupos: alta e baixa flutuação de massa seca. As análises estatísticas foram feitas com auxílio do programa computacional R (versão 3.2.3). Utilizou-se um modelo de regressão linear misto para analisar os dados, no qual os experimentos e baias foram considerados como variáveis aleatórias e grupos de flutuação como variável fixa. Os grupos de baixa e alta flutuação apresentaram flutuação média de 4,79 e 6,47%, respectivamente. O grupo de baixa flutuação de ingestão de massa seca apresentou maior ingestão de massa seca em % do peso vivo (P < 0,01), maior ganho de peso diário (P = 0,05), maior ingestão de massa seca em kg (P = 0,06), maior ganho de peso total (P = 0,08), além de maior deposição em área de olho de lombo (P = 0,03) e menor força de cisalhamento (P = 0,03). Com relação ao comportamento ingestivo, o grupo de baixa flutuação de ingestão de massa seca apresentou maior taxa de eficiência da alimentação da massa seca, maior taxa da eficiência da ruminação da massa seca (P = 0,09), maior tempo de ruminação (P = 0,04) e menor tempo em ócio (P = 0,06), além de menor número de idas ao bebedouro (P = 0,04). Não foram observadas diferenças no perfil metabólico sanguíneo, incidência de rumenites e morfologia das papilas ruminais entre os dois grupos avaliados. Menor flutuação na ingestão de massa seca melhora o desempenho e ganho em musculatura de bovinos confinados.<br>This study aimed to evaluate the inpact of natural dry matter intake fluctuation on performance, carcass characteristics, feeding behavior, blood metabolic profile and morphophysiological ruminal aspects of cattle fed with diets of high inclusion of concentrate. The experiments used for this meta-analysis used cattle with genetic group similar to used in Brazilian commercial feedlots. The meta-analysis was conducted using a database of results of ten experiments conducted in Experimental Feedlot of Faculty of Veterinary Medicine and Animal Science, UNESP, Botucatu, between the years 2006 and 2015. Data were collected from 838 bulls, divided into 238 pens, considered the experimental units for the study. The values of dry matter intake fluctuation were calculated by the difference in dry matter intake between consecutive days and divided by the previous day to find the value in percentage. Based on the overall median of 5.62% cattle were classified into two groups: high- or low-fluctuation. All data analysis was performed in R using a mixed model approach where pens and year were random variables and fluctuation group fixed. The low and high fluctuation groups presented a dry matter intake fluctuation average of 4.79% and 6.74%, respectively. Low fluctuation group showed higher dry matter intake as percent of body weight (P <0.01), higher average daily gain (P = 0.05), higher dry matter intake in kg (P = 0.06), greater total weight gain (P = 0.08), as well as greater deposition in rib eye area (P = 0.03), and lower shear force (P = 0.03). In relation to feeding behavior, low dry matter intake variation group showed higher intake efficiency rate of dry matter, higher rumination (P = 0.04) and less resting time (P = 0.06), as well as fewer visits to the drinker (P = 0.04). There were no differences in blood metabolic profile, incidence of rumenites and morphology of rumen papillae between two groups. Low dry matter intake fluctuation improves feedlot cattle performance and gain muscle.

O objetivo desse estudo foi avaliar o desempenho, o perfil de ácidos graxos e os parâmetros ruminais de ovinos alimentados com co-produtos da indústria citrícola em rações contendo alta proporção de concentrado. Adicionalmente, foram comparadas as estimativas de desempenho e de metabolismo obtidas nos experimentos com as preditas pelo modelo SRNS Small Ruminant Nutrition System No experimento I, 28 ovelhas foram alimentadas com ração composta por 55% de milho na matéria seca (MS), sendo o milho substituído em 33%, 67% e 100% pela polpa cítrica desidratada (PCD). Houve diminuição linear (P<0,02) no consumo de matéria seca (CMS) à medida que a PCD substituiu o milho, entretanto, não houve efeito na produção de leite. Não houve alteração dos componentes do leite, com exceção do teor de uréia que diminuiu linearmente (P<0,01). Em relação ao perfil de ácidos graxos (AG) no leite das ovelhas foi verificado aumento linear (P<0,05) de C15:0, C16:0, C17:1, C18:3, AG de cadeia média e saturados, e diminuição linear (P<0,05) de C18:0, C18:1, C18:2 t10,c12, AG monoinsaturados e de cadeia longa. Para o C18:2 c9,t11 houve aumento de 47% quando a PCD substituiu o milho em 33%. No experimento II, 32 cordeiros foram alimentados com ração contendo 90% de concentrado, sendo o milho substituído pela PCD em 33, 67 e 100%, respectivamente. A substituição total do milho pela PCD promoveu aumento (P<0,03) de 177% na concentração de C18:3, enquanto que a substituição parcial (33%) resultou em aumento (P<0,02) de 72% no C18:2 c9,t11. Adicionalmente, ocorreu diminuição linear (P=0,02) do extrato etéreo com a adição de PCD na ração. No experimento III, na avaliação de desempenho, 64 cordeiros foram alimentados com rações contendo 69,5% de PCD, sendo esta substituída em 30% na MS pela polpa cítrica úmida semi despectinada in natura (PCUD), ensilada (PCUDS) ou ensilada com adição de benzoato de sódio (PCUDS+B). Não houve diferença no CMS e no ganho médio diário (GMD). No entanto, a eficiência alimentar foi maior para os cordeiros alimentados com PCUD comparados àqueles recebendo ração contendo PCD. Na avaliação da digestibilidade e de parâmetros ruminais, 16 cordeiros, canulados no rúmen foram alimentados com rações contendo 75,3% de PCD, sendo esta substituída em 30% na MS pela PCUD, PCUDS ou PCUDS+B. Não houve diferença nos coeficientes de digestibilidade para MS, MO e PB, com exceção para o da FDN que foi maior (P<0,05) para a PCUD comparada à PCD. A concentração de amônia no fluido ruminal foi maior (P<0,01) para as rações contendo PCD comparada à PCUDS e PCUDS+B. No experimento IV, 24 cordeiros foram alimentados com rações contendo 70% de PCD na MS e tiveram a adição de 0; 0,3; 0,6 e 0,9% de monoamônio fosfato (MAP). Houve diminuição linear (P<0,01) no CMS e GMD com a inclusão de MAP na ração. No experimento V foi observada melhor predição de CMS para os cordeiros em relação às ovelhas.<br>The objective of this study was to evaluate the performance, fatty acids (FA) profile and ruminal measures of sheep fed citrus coproducts in diets containing high concentrate. Additionally, the performance and metabolic estimates from SRNS model - Small Ruminant Nutrition System were compared to experimental data. In Experiment I, 28 ewes were fed diet containing 55% of corn. Dried citrus pulp (DCP) was added at 18.1, 36.8 and 55% (diet DM) replacing corn by 33, 67 and 100%, respectively. There was a linear decrease (P<0.02) in dry matter intake (DMI) with DCP inclusion, however, there was no effect on milk production. Milk composition, was not affected by DCP inclusion, except for urea that showed a linear (P<0.01) decrease. Milk FA increased linearly for C15:0, C16:0, C17:1, C18:3, medium-chain and saturated FA and decreased linearly for C18:0, C18:1, C18:2 t10,c12, monounsaturated and long-chain FA when DCP replaced corn. There was a 47% increase for C18:2 c9,t11 when DCP replaced corn by 33%. In Experiment II, 32 Santa Ines lambs were fed a 90% concentrate. DCP was added at 23.7, 46.1 and 68.4% (on a DM basis) replacing corn by 33, 67 and 100%, respectively. Total replacement of corn by DCP promoted an increase (P<0.03) by 177% in linolenic acid (C18:3) while a partial replacement showed an increase (P<0.02) by 72% in conjugated linoleic acid (C18:2 c9,t11). In addition, ether extract decrease (P=0.02) as DCP increased in the diet. In Experiment III, 64 lambs were fed diets containing 69.5% DCP. A portion (30%) of DCP on a DM basis was replaced by wet low pectin citrus pulp (WLPCP), wet low pectin citrus pulp silage (WLPCPS) or wet low pectin citrus pulp silage with sodium benzoate (WLPCPS+B). There were no differences in DMI and average daily gain (ADG). However, feed efficiency was greater for lambs fed WLPCP compared to lambs fed DCP. In the digestibility trial, 16 lambs, canulated in the rumen, were fed diets containing 75.3% DCP. A portion (30%) of the DCP was replaced by WLPCP, WLPCPS or WLPCPS+B. There was no difference (P>0.05) in dry matter, organic matter and crude protein apparent digestibilities, except for neutral detergent fiber digestibility (82.7 vs 73.3% for WLPCP and DCP, respectively). Additionally, ruminal ammonia concentration was higher (P<0.01) in diets containing DCP compared to WLPCPS and WLPCPS+B. In experiment IV, 24 Santa Ines lambs were fed diets containing 70% DCP and monoammonium phosphate (MAP) was added at 0, 0.3, 0.6, and 0.9% of the diet DM There was a linear decrease (P<0.01) in DMI and ADG. In experiment V DMI predictions were better estimated for lambs compared to DMI of ewes.

Thesis (MSc)--Stellenbosch University, 2000.<br>ENGLISH ABSTRACT: Six groups each with six Friesian bull calves were used in this investigation and slaughtered at 20 weeks of age. Calves received a low- (LD) or high (HD) degradable protein diet, each with or without rumen inert fat supplementation. Two commercial fat sources were used, Morlae (m) and Golden Flake (gf), included at 2.5% of the diet. A commercial milk replacer (Denkavit) was fed at 4L for 42 days, followed by 2L until weaning at 49 days of age. The starter diets were fed ad lib. from day 14 to 10 weeks of age and finishing diets ad lib. from 11 to 20 weeks of age. There were no significant differences in body mass gain or dry matter intake over the entire 20 week period. The feed conversion ratio (FCR) was improved significantly (P=0.0032) when fat was supplemented to LD, but not to HD diets. The FCR (kg dry matter/ kg gain) ofLD, HD, LDm, HDm, LDgfand HDgfdiets were 3.45,3.44,3.07, 3.81, 3.02 and 3.43, respectively. All 36 calves were used in a digestibility trial, using chromium oxide (Cr203) as a marker, during week 18 of the investigation. Digestibility values (%) for the six diets (LD, HD, LDm, HDm, LDgfand HDgf) were 61.74, 65.91, 75.44, 69.00, 75.54 and 67.15 for dry matter, 61.44, 61.60, 71.33, 68.23, 75.44 and 66.12 for crude protein and 58.56, 66.45, 75.98, 70.92, 78.43 and 70.79 for fat, respectively. The dry matter (P=O.OOOl)and fat (P=O.OOOl) digestibilities were only significantly higher when fat was added to LD diets. The crude protein (CP) digestibilities were significantly higher when fat was added to either the LD (P=0.0001) or the HD (P=0.0488) diets. All the calves were slaughtered at 20 weeks of age and the fatty acid content of the meat (m. longissimus) and subcutaneous fat layer adjacent to the 12th rib as well as the meat colour, was determined. The fatty acid composition of the longissimus muscle was changed by feeding the rumen inert fat sources. The three predominant fatty acids found were palmitic, stearic and oleic acids. The palmitic acid (CI6:0) content of the muscle and diet was 24.44 & 20.47,25.97 & 22.57,31.06 & 33.23, 30.98 & 37.91, 34.94 & 31.77 and 29.71 & 32.88 of the total fat for the LD, HD, LDm, HDm, LDgf and HDgf diets, respectively. The C16:0 content was significantly higher in the muscle of the calves receiving the LD diets supplemented with fat (P=0.0008). There was also a significant interaction between the two fat sources and protein degradability (P=0.0065), but only in the LD diets. The stearic acid (CI8:0) content of the muscle and diet was 14.35 & 5.22, 19.65 & 8.61, 17.29 & 4.68, 22.59 & 5.78, 22.27 & 15.54, and 26.48 & 20.15 of the total fat for the LD, HD, LDm, HDm, LDgfand HDgfdiets, respectively. The C18:0 content was significantly higher in the muscle of calves receiving the HD (P=O.OOOl)compared to LD diets. The stearic acid content was also significantly higher when fat was added to LD (P=0.0042) or HD (P=0.0073) diets. The oleic acid (CI8:1) content of the muscle and diet was 36.06 & 21.51,39.99 & 21.11,32.21 & 23.67, 29.13 & 24.59, 25.23 & 18.68 and 35.93 & 16.02 of the total fat for the LD, HD, LDm, HDm, LDgf and HDgf diets, respectively. The linolenic acid (CI8:3) content of the muscle was significantly higher (P=0.0038) when fat was added to LD diets compared to no fat supplementation (0.87 vs. 0.15). The CIELAB values indicated that LD diets resulted in more pink meat. Mean values ofL* =-32.61, 34.19; a* = 7.08, 7.91 and b* = 3.18 and 4.07 were observed for the LD and HD diets, respectively. Meat from the LD diets had significantly lower L*-(P=0.0252), a*-(P=0.0283) and b*-(P=0.0109) values compared to meat from the HD diets. It was concluded that there was a positive response in CP digestibility when rumen inert fats were supplemented to LD or HD diets, although a greater response was shown in the LD diets. The FCR, dry matter and fat digestibility were only increased when fat was added to the LD and not to the HD diets. Similarly, the fatty acid contents of the longissimus muscle of veal calves can be manipulated with the supplementation of rumen inert fat sources, but only when combined with a low protein degradable diet. The low degradable protein diets also produce a more attractive meat colour for the potential veal consumer.<br>AFRIKAANSE OPSOMMING: Ses behandelings, lae- (LD) of hoë (HD) degradeerbare diëte, elk met of sonder rumeninerte vetsupplementering, is geëvalueer met ses kalwers in elke groep. Twee kommersiële vetbronne is gebruik, nl. Morlae (m) en Golden Flake (gf) teen 'n 2.5% insluitingspeil. 'n Kommersiële melksurrogaat (Denkavit) is aangebied teen 4L1dag tot 42 dae ouderdom, gevolg deur 2L/dag tot speenouderdom op 49 dae. Aanvangsdiëte is ad lib. aangebied vanaf 14 dae tot 10 weke ouderdom en die groeidiëte ad lib. vanafweek 11 tot 20. Daar was geen betekenisvolle verskille in die totale massatoename of die droëmateriaalinname nie. Die voeromsettingsverhouding is betekenisvol verbeter (P=0.0032) in die behandelings waarin rumeninerte vette by LD diëte ingesluit is, maar nie by die HD diëte nie. Die voeromsettingsverhouding (kg droëmateriaalinname / kg massatoename) van die LD, HD, LDm, HDm, LDgf en HDgf diëte was 3.45, 3.44, 3.07, 3.81, 3.02 en 3.43, onderskeidelik. Al 36 kalwers is in 'n verteringsproef gebruik gedurende week 18 van die proef. Chroomoksied (Cr203) is as merker gebruik. Verteerbaarheidswaardes vir die ses diëte was 61.74, 65.91, 75.44,69.00,75.54 en 67.15 vir droëmateriaal, 61.44, 61.60, 71.33, 68.23, 75.44 en 66.12 vir ruproteïen en 58.56, 66.45, 75.98, 70.92, 78.43 en 70.79 vir vet, onderskeilik. Die droëmateriaal- (P=O.OOOl) en vetverteerbaarheid (P=O.OOOI) was slegs betekenisvol hoër wanneer vet by LD diëte gevoeg is en nie by HD nie. Die ruproteïen (RP) verteerbaarheid Stellenbosch University http://scholar.sun.ac.za VI was betekenisvol hoër (P=0.0002) by LD en HD (P=0.0488) diëte met vet supplementering, teenoor geen vet insluiting. Die kalwers is op 20 weke ouderdom geslag en die vetsuursamestelling van die vleis (m. longissimus) en die subkutane vetlaag teenaan die 12de rib, asook en die vleiskleur, is bepaal. Die vetsuursamestelling van die longissimus spier is deur die supplementering van rumeninerte vet verander. Die drie primêre vetsure wat in die vleis voorgekom het, was palmitiensuur, steariensuur en oleïensuur. Die palmitensuur (CI6:0) inhoud van die spier en diëte was 24.44 & 20.47, 25.97 & 22.57, 31.06 & 33.23, 30.98 & 37.91, 34.94 & 31.77 en 29.71 & 32.88 van die totale vet van die LD, HD, LDm, HDm, LDgf en HDgf diëte, onderskeilik. Die C16:0 was betekinisvol hoër in die spiere van kalwers wat die LD diëte met vet supplementering (P=0.0008) ontvang het. Die steariensuur (CI8:0) inhoud van die spier en diëte was 14.35 & 5.22, 19.65 & 8.61, 17.29 & 4.68, 22.59 & 5.78, 22.27 & 15.54, en 26.48 & 20.15 van die totale vet vir die LD, HD, LDm, HDm, LDgf en HDgf diëte, onderskeidelik. Die C18:0 inhoud was betekinisvol hoër in die spiere van die kalwers wat die HD (P=O.OOOI),teenoor LD diëte ontvang het. Die steariensuur inhoud was ook betekenisvol hoër wanneer vet by LD (P=0.0042) of HD (P=0.0031) diëte gevoeg word. Die oleïensuur (CI8:1) inhoud van die spier en diëte was 36.06 & 21.51, 39.99 & 21.11, 32.21 & 23.67, 29.13 & 24.59, 25.23 & 18.68 en 35.93 & 16.02 van die totale vet vir die LD, HD, LDm, HDm, LDgf en HDgf diëte, onderskeidelik. Die linoleensuur (CI8:3) inhoud van die spier was betekinisvol hoër (P=0.0038) in die LD diëte met vet teenoor LD met geen vet supplementering (0.87 vs. 0.15). Die CIELAB waardes van die LD diëte dui op 'n pienker vleiskleur. Gemiddelde waardes van L* = 32.61 & 34.19, a* = 7.08 & 7.91 en b* = 3.18 & 4.07 is vir die LD en HD diëte, onderskeidelik, waargeneem. Die vleis van die LD diëte het 'n betekenisvol laer L*-(P=0.0252), a*-(P=0.0283) en b*-(P=0.0109) waarde in vergelyking met die HD diëte getoon. Die resultate dui daarop dat daar 'n positiewe respons in die ruproteïenverteerbaarheid by die supplementering van rumeninerte vette by LD en HD diëte voorkom, maar die response op die LD diëte is groter. Die voeromsettingsverhouding, droëmateriaal- en vetverteerbaarheid is egter net bevoordeel in die LD met vet en nie in die HD diëte nie. Die vetsuursamestelling van die longissimus spier in die kalf kan gemanipuleer word met die supplementering van rumeninerte vetbronne, maar slegs wanneer dit gekombineer word met lae degradeerbare proteïen diëte. Die lae degradeerbare proteïen diëte produseer ook die mees aanloklike vleiskleur vir die potensiële kalfsvleisverbruiker.

Attempts to improve upon the crude protein feeding system have strived to characterize feedstuffs with respect to ruminal protein degradability. In vitro an in situ procedures fall short of this goal by not accounting for ruminal turnover. Six lactating cows, fitted with ruminal and duodenal cannulae, were utilized for in vivo determination of protein degradability by employing a double-marker system. Treatments were corn silage-based diets supplemented with 2:1 soybean meal:fish meal nitrogen (SF) or 1:2 soybean meal:fish meal nitrogen (FS) at levels of 15. 9 and 16.0 percent protein. Ruminal cobalt ethylenediaminetetraacetic acid (CoEDTA) infusions marked liquid phase (LP) digesta and Yb-soaked hay was used as a solid phase (SP) marker. Duodenal digesta was separated into SP and LP at 3000xg. Least squares means of LP flows did not differ for total, precipitable protein, or microbial nitrogen, for SF and FS. Total solid phase flow of dry matter was higher for FS (9.06 kg/d) than for SF (7.97 kg/d), although intakes did not differ. Milk composition and yield did not differ for FS and SF. Average daily gain was 0.12 kg/d for SF and 1:26 kg/d for FS. Whole-tract digestibilties were not different although rumen digestibility of dry matter was 24.9% for FS and 35.7% for SF, and duodenal recovery of N was 93.8% for SF and 107.5% for FS. Inclusion of a higher level of fish meal in the diet increased the proportion of feed proteins delivered to the small intestine, increasing weight gain while having no effect on milk production.<br>Master of Science

A pecuária de corte no Brasil evoluiu muito em produtividade e qualidade do produto final, determinantes para a manutenção da atividade. A pesquisa no setor pecuário visa incrementar o lucro ao pecuarista, auxiliar na melhora das carcaças para o frigorífico e garantir carne de qualidade ao consumidor. A raça Nelore, amplamente difundida pelo país, sofre com o manejo nutricional deficiente, que prejudica o desempenho produtivo. O grão de milho é muito utilizado como fonte energética para os bovinos e estudos buscam melhorar o aproveitamento do amido do grão, como o fornecimento de grãos processados como milho úmido. Outra fonte energética para a suplementação de bovinos seria a gordura protegida da degradação ruminal. Neste experimento objetivou-se ampliar o conhecimento dos efeitos de alimentos energéticos (dietas contendo grão de milho seco ou úmido com ou sem gordura protegida da degradação ruminal) sobre a digestibilidade total, composição corporal e da carne de novilhos da raça Nelore. Não houve efeito dos tratamentos sobre os coeficientes de digestibilidade ou para a porcentagem de nutrientes digestíveis totais. Os tratamentos também não alteraram a composição corporal e as exigências líquidas de energia e proteína para ganho de peso. A inclusão de gordura à dieta reduziu a porcentagem de água e elevou o extrato etéreo da carne. Quanto ao perfil de ácidos graxos, o milho úmido aumentou os poliinsaturados, e a inclusão da gordura os ômega 6. Os cortes cárneos diferiram tanto na composição química quanto no perfil de ácidos graxos.<br>The beef cattle in Brazil have been a great development on productivity and quality of end product. These are decisive for the maintenance of the activity. Researchs about cattle look for to increase the profit to the farmer, improve the quality of carcasses for slaughtered and to guarantee quality meat to consumer. Nelore breed, the mostly cattle of Brazilian herd, suffers with deficient nutricional handling that reduce the performance of animals.The corn grain is very used as energy source for catlle and researchs look for to improve the digestibility of starch of grain, as the supply of processed grains as high moisture corn grain. Another energy source for feed cattle is ruminal protected fat. In this study looks for increased the knowledge of effects of energetic foods (diets containing dry or high moisture corn grain with or without ruminal protected fat) on total digestibility, body composition and meat composition of Nellore breed steers. There was no effect of diets on digestibility coefficients or The percentage total digestible nutrients. Diets didn't also change the body composition and net requirements of energy and protein for weight gain. The addition of fat reduced the percentage of water and increased ether extract in the meat. About the fatty acids profile, high moisture corn grain increased polyunsaturated, and fat increased omega 6. Meat cuts differed in chemical composition and fatty acids profile.

Orientador: Mário De Beni Arrigoni<br>Resumo: O presente estudo teve o objetivo de avaliar o impacto da flutuação natural da ingestão de massa seca no desempenho, características de carcaça, comportamento ingestivo, perfil metabólico sanguíneo e aspectos morfofisiológicos ruminais de bovinos alimentados com dietas de alta inclusão de concentrado, por meio de estudo meta-analítico. Os experimentos contidos na meta-análise utilizaram animais com grupamento genético similar ao utilizado em confinamentos comerciais brasileiros. A meta-análise teve como base de dados os resultados de dez experimentos conduzidos no Confinamento Experimental da Faculdade de Medicina Veterinária e Zootecnia da UNESP, em Botucatu, entre os anos de 2006 e 2015. Os dados foram coletados a partir 838 bovinos, divididos em 238 baias, consideradas as unidades experimentais para o estudo. Os valores de flutuação de ingestão de massa seca na baia foram calculados pela diferença da ingestão de massa seca entre dois dias consecutivos e dividido pelo dia anterior para encontrar o valor em porcentagem. Com base na mediana geral de 5,62%, os animais foram divididos em dois grupos: alta e baixa flutuação de massa seca. As análises estatísticas foram feitas com auxílio do programa computacional R (versão 3.2.3). Utilizou-se um modelo de regressão linear misto para analisar os dados, no qual os experimentos e baias foram considerados como variáveis aleatórias e grupos de flutuação como variável fixa. Os grupos de baixa e alta flutuação apresentaram flutuação mé... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: This study aimed to evaluate the inpact of natural dry matter intake fluctuation on performance, carcass characteristics, feeding behavior, blood metabolic profile and morphophysiological ruminal aspects of cattle fed with diets of high inclusion of concentrate. The experiments used for this meta-analysis used cattle with genetic group similar to used in Brazilian commercial feedlots. The meta-analysis was conducted using a database of results of ten experiments conducted in Experimental Feedlot of Faculty of Veterinary Medicine and Animal Science, UNESP, Botucatu, between the years 2006 and 2015. Data were collected from 838 bulls, divided into 238 pens, considered the experimental units for the study. The values of dry matter intake fluctuation were calculated by the difference in dry matter intake between consecutive days and divided by the previous day to find the value in percentage. Based on the overall median of 5.62% cattle were classified into two groups: high- or low-fluctuation. All data analysis was performed in R using a mixed model approach where pens and year were random variables and fluctuation group fixed. The low and high fluctuation groups presented a dry matter intake fluctuation average of 4.79% and 6.74%, respectively. Low fluctuation group showed higher dry matter intake as percent of body weight (P <0.01), higher average daily gain (P = 0.05), higher dry matter intake in kg (P = 0.06), greater total weight gain (P = 0.08), as well as greater depositio... (Complete abstract click electronic access below)<br>Mestre

The livestock sector is facing different challenges, and the demand for higher sustainability seems to be one of the most urgent. This PhD project debated, in particular, the environmental impacts related to ruminant nutrition, focusing on dairy cows, since nutrition is bound tightly to two of the most important sources of impact: enteric CH4 emission and land use change (LUC). Enteric CH4 emission from ruminants represents 29-38% of the total (anthropic + natural) emission of this powerful (21 CO2 equivalent) greenhouse gas. The production of CH4 is a physiological process used by ruminants to discharge the [H] resulting from rumen fermentation. Different strategies can be implemented to mitigate this impact, and they can be roughly grouped into three main categories: animal and feed management, diet formulation, and rumen manipulation. The second issue investigated in the project is the high reliance of European livestock on soybean meal as a protein source for diet formulation. A total of 30 million tonnes of this feedstuff was imported into Europe in 2020. The main countries of origin are in South America (65% of total import), where 20% of soybean meal production was linked with deforestation (and consequently LUC) in the last decades. Clearing these areas means loss of carbon sink and emission of CO2 in the atmosphere. Other feedstuffs, like grain legumes, oilseed meals alternative to soybean, and high quality forages could be considered to provide protein feed with a lower environmental cost. In this context, the PhD project was developed as follows:  To address the problem of CH4 emission, plant essential oils, as modulators of rumen fermentation, were evaluated (Experiment 1). Furthermore, the effect on CH4 emission of different forages in the diet of dairy cows was investigated (Experiment 2). For validation of mitigation strategies and inventory computation of emissions at a national scale, country-specific equations to quantify CH4 emission were evaluated (Experiment 3).  To address the problem of soybean meal environmental impact, soybean silage and responsible soybean meal (not connected with land use change) were evaluated as protein source alternatives to soybean meal in the diet of lactating cows (Experiments 4 and 5). Enteric methane direct emission In the first experiment, Achille moschata essential oil and its main pure components, namely bornyl acetate, camphor, and eucalyptol, were evaluated in an in vitro experiment. The trial comprehended a short-term in vitro incubation (48 h), with 200 mg of compound per L of inoculum, and a long-term one by continuous fermenter (9 d), with 100 mg/L for each compound. In the first incubation, no differences due to the treatments were found for in vitro gas production (on average, 30.4 mL/200 mg DM, P = 0.772 at 24 h and 45.2 mL/200 mg DM, P = 0.545 at 48 h). Camphor and eucalyptol reduced CH4 production when expressed as % of gas production at 48 h (P &lt; 0.05): -7.4% and -7% compared to control. In the second incubation, CH4 was reduced by eucalyptol (-18%, P &lt; 0.05). Regarding volatile fatty acids, the main effects were a decrease of total production for camphor (-19.5%, P &lt; 0.05) and an increase in acetate production at 9 d with bornyl acetate and camphor (+13% and 7.6%, respectively, P &lt; 0.05) compared to control. Total protozoa count was increased compared to the control (on average: +37%, P = 0.006, at 48 h and +48%, P &lt; 0.001, at 9 d) with all the pure compounds tested. In the short-term incubation, all the treatments reduced Bacteroidetes (30.3%, on average, vs. 37.1% of control, P = 0.014) and Firmicutes (26.3%, on average, vs. 30.7% of control, P = 0.031) abundances but increased Proteobacteria (36.0%, on average, vs. 22.5% of control, P = 0.014). In the long-term incubation, eucalyptol increased the genus Ruminococcus abundance (2.60% vs. 1.18% of control, P = 0.011). An adaptation at long time incubation was observed. In particular, considering eucalyptol addition at 9 d incubation, VFA production was reduced (26.8 vs. 33.3 mmol of control, P &lt; 0.05) contrary to the 48 h incubation (P = 0.189). Furthermore, the treatments affected protozoa genera relative abundances at 24 h (increased abundance for Entodinium with all the treatments, P &lt; 0.001, and reduced for Diplodinium, P = 0.001); at 9 d, instead, protozoa genera relative abundances were not affected by the treatment. The additives tested showed potential in reducing CH4 production without compromising the overall fermentation efficiency. A meta-analysis (Experiment 2) investigated the effects on lactation performance and enteric CH4 of the main forage included in the diet. In the dataset, composed of in vivo experiments, four main forage bases were evaluated: corn silage, alfalfa silage, grass silage, and green forage. Cows fed corn, and alfalfa silages had the highest DMI (21.9 and 22.0 kg/d, P &lt; 0.05) and milk yield (29.7 and 30.4 kg/d, P &lt; 0.05). On the opposite, NDF digestibility was highest for grass silage and green forage (67.6% and 73.1%, P &lt; 0.05) than corn and alfalfa silages (51.8% on average). CH4 production was lower (P &lt; 0.05) for green forage (332 g/d) than the silage diets (on average 438 g/d). Instead, corn silage and alfalfa silage gave the lowest CH4 per kg of milk yield (14.2 g/kg and 14.9 g/kg, P &lt; 0.05). Considering CH4 per kg of DMI, the only difference was between corn silage and grass silage (19.7 g/kg vs. 21.3 g/kg respectively for corn and grass silage, P &lt; 0.05). Finally, prediction models for CH4 production were obtained through a step-wise multi regression. In particular, the models for the prediction of: CH4 in g/d (CH4 = - 65.3(±63.7) + 11.6(±1.67) × DMI - 4.47(±1.09) × CP - 0.86(±0.33) × Starch + 2.62(±0.78) × OM digestibility + 30.8(±9.45) × Milk fat) and for CH4 in g/kg of milk yield (CH4/milk yield = - 55.5(±20.1) - 0.37(±0.13) × DMI + 0.18(±0.05) × Total forage inclusion on diet DM - 0.10(±0.04) × Inclusion of the main forage on diet DM + 0.48(±0.21) × OM + 0.14(±0.06) × NDF + 1.98(±0.86) × Milk fat +4.34(±1.66) × Milk protein) showed high precision (R2 = 95.4% and 88.6%, respectively), but the best AIC value (320) was found for the model predicting CH4 in g/kg DMI: CH4/kg DMI = 6.16(±3.89) - 0.36(±0.03) × CP + 0.12(±0.05) ×OM digestibility + 3.77(±0.56) × Milk fat - 3.94(±1.07) × Milk fat yield. A dataset (66 observations in total) of three in vivo experiments conducted in Italy on lactating cows in respiration chambers was built to evaluate IPCC Tier 2 equations to estimate enteric CH4 production (Experiment 3). In the dataset, the CH4 conversion factor (conversion of gross energy intake into enteric CH4 energy) was lowest for a diet based on grass and alfalfa silages (5.05%, P &lt; 0.05), while the others values ranged between 5.41 and 5.92%. On average, energy digestibility was 69.0% across the dataset, but the diet based on hays had a lower value (64.8%, P &lt; 0.05). The IPCC (2019) Tier 2 (conversion factor = 5.7% or 6.1% for diet with NDF concentration &lt; 35% or &gt;35%, respectively; digestible energy = 70%) gave, on average, a value of CH4 production not statistically different from the ones measured in vivo (382 vs. 388 g/d in vivo, P &gt; 0.05). The IPCC (2006) Tier 2 (conversion factor = 6.5%, digestible energy = 70%) over-predicted CH4 emission (428 vs. 388 g/d in vivo, P &lt; 0.05; μ = -1.05). The most precise models were the two considering digestible energy equal to 70% and average values of conversion factor for IPCC (2006) and IPCC (2019) (R = 0.630); the most accurate models was the one considering a conversion factor equal to 5.7% and energy digestibility measured in vivo (Cb = 0.995). Overall, the best performance among the predicting models tested was for the one based on a conversion factor equal to 5.7% and energy digestibility of 70% (CCC = 0.579 and RMPSE = 9.10%). Use of alternative protein source to conventional soybean meal The dietary inclusion of soybean silage in partial replacement of soybean meal for dairy cows was evaluated in vivo in lactating cow diets (Experiment 4). Cows were fed two diets, one with 12.4% of DM from soybean silage in substitution of 35% of the soybean meal of the control diet. The treatment did not affect DMI and milk yield (on average, 23.7 kg/d, P = 0.659, and 33.0 kg/d, P = 0.377, respectively). Cows fed the soybean silage diet had lower milk protein concentration (3.43% vs. 3.55% of the control, P &lt; 0.001) and higher milk urea (30.5 vs. 28.7 mg/dL, P = 0.002). The soybean silage had lower nutrient digestibility than the control: DMD 65.2% vs. 68.6%, OMD 66.4% vs. 69.8%, NDFD 31.5% vs. 38.8% (respectively for soybean silage and control diet; P &lt; 0.001 for all of them). Regarding N balance, cows fed soybean silage excreted more nitrogen in the urines (32.3 % of N intake vs. 28.9%, P = 0.005) and less in the milk (31.3% vs. 32.7%, P =0.003) than the control. When used as a protein source alternative to soybean meal, soybean silage sustained comparable milk production, but NDF digestibility and N use efficiency should be improved. The environmental impact of the use of soybean silage in comparison to a control diet with soybean meal as the main protein source was evaluated through an LCA approach (Experiment 5). In addition, two scenarios were included in the study, considering the two diets mentioned before, but with soybean meal not connected to LUC (responsible soybean meal). Regarding the single forages, soybean silage had higher global warming potential than alfalfa hay (477 vs. 201 kg CO2eq/ton DM), also when this was expressed per tonnes of protein production (2439 and 1034 kg CO2eq/ton CP, respectively), probably due to the lower contribution of the cultivation phase for alfalfa, being a multi-year crop. The scenario with soybean silage reduced the global warming potential per kg of fat and protein corrected milk (1.17 kg CO2eq) compared to the control (1.38 kg CO2eq). Responsible soybean meal reduced the global warming potential per kg of fat and protein corrected milk (1.13 kg CO2eq/kg vs. 1.38 of the scenario with the control diet). Overall, the best result per kg of fat and protein corrected milk was obtained when responsible soybean meal and soybean silage were used in combination (1.01 kg CO2eq). Also, when global warming potential was evaluated per daily fed TMR, the impact was lowest for the scenario with responsible soybean meal (13.4 kg CO2eq/d) due to the lower contribution of soybean meal to the total impact (11% vs. 43% of the control). Therefore, the two alternative protein sources tested should be preferred when considering environmental impact compared to conventional soybean meals.

Aim of this thesis was to explore the effects of suboptimal N supplies on animals of different species on production performances to achieve an effective reduction of N excretion avoiding, or limiting, the economic losses due to impairment of performance or reduced quality of products. As aside different methods of fatty acid analysis were evaluated to identify an accurate and repeatable methodology of extraction of fatty acids that prevents isomerisation of PUFA and conjugated linoleic acid. All the contributions of this thesis have been published or submitted to international peer reviewed journals. This thesis was also reviewed by foreign referees and all their suggestions were accepted and included in the present version of this thesis. The first two contributions were aimed to verify the effect of suboptimal dietary crude protein supply on growing cattle and lactating cows. In lactating cows the effect of a supplementation with rumen protected conjugated linoleic acid (CLA) was also explored. The third contribute regards an experiment conducted to evaluate the effect of different fecal sample preparation procedures to determine the fatty acid profile of ruminants feces, including CLA. The fourth and the fifth contributions were aimed to evaluate the effects of reduced dietary crude protein and amino acid levels on growth performance of heavy pigs (4th contribute) and on growth performance and intramuscular lipid deposition on fast growing pigs (5th contribute). Overall, the results suggests that considerable reduction of dietary crude protein, compared to conventional standard, can be applied with small or null impairment of production response, but with a notable reduction of N excretion. Within the framework of the nitrate directive of the European Community, the strong reduction of N excretion achieved with the use of suboptimal protein supplies would result in the possibility of increasing the number of animals reared per unit of land available for manure disposal, and to reduce the feeding costs because of less use of expensive dietary protein sources. From the third contribute it resulted that fecal sample preparation method has an influence on fecal fatty acid profile, and in particular on the CLA component, stronger than that was previously evidenced in the literature that indicated the methylation as a critical step for an accurate analysis of fatty acids by gas chromatography. Analytical methods applicable on different biological substrates (feeds, feces, and animal products) are needed for a better knowledge of lipid digestion and metabolism of farm animals.<br>Scopo di questa tesi è stato quello di esplorare gli effetti conseguenti ad una somministrazione subottimale di proteina ad animali di diverse specie sulle performance produttive per poter ottenere una riduzione effettiva della escrezione di N ed evitare, o limitare, le perdite economiche dovute al peggioramento delle prestazioni o alla riduzione della qualità dei prodotti. Un capitolo a parte della tesi è stato di valutare diversi metodi di analisi degli acidi grassi per identificare una metodologia accurata e ripetibile di estrazione degli acidi grassi in grado di prevenire l’isomerizzazione degli acidi grassi polinsaturi in particolare dei coniugati dell’acido linoleico. Tutti i contributi presentati in questa tesi sono stati pubblicati o sottoposti riviste scientifiche internazionali. Questa tesi è stata valutata da due docenti stranieri e i loro suggerimenti sono stati accettati e inclusi nella versione finale di questa tesi. I primi due contributi sono stati finalizzati a verificare l'effetto di diete contenenti concentrazioni subottimali di proteina grezza, somministrate a bovini da carne e vacche in lattazione. Nelle vacche in lattazione è stato anche valutato l'effetto conseguente alla somministrazione di acido linoleico coniugato (CLA) rumino protetto. Il terzo contributo riguarda un esperimento condotto per valutare l' effetto di differenti procedure di preparazione dei campioni fecali per determinare il profilo degli acidi grassi, compresi i CLA, nelle feci dei ruminanti. Il quarto ed il quinto contributo sono finalizzati a valutare gli effetti della riduzione nella dieta dei livelli di proteina grezza e degli amminoacidi sulle performance di crescita dei suini pesanti (4° contributo) e sulle performance di crescita e di deposizione lipidica intramuscolare in suini selezionati per una crescita rapida e magra (5° contributo). Complessivamente, i risultati suggeriscono che una notevole riduzione del livello proteico della dieta, rispetto a standard tradizionali, può essere applicato compromettendo lievemente o per nulla la risposta produttiva, ma con una notevole riduzione di escrezione azotata. Nell'ambito della direttiva nitrati della Comunità Europea, la forte riduzione dell'escrezione di N ottenuto grazie all' impiego di diete ipoproteiche può comportare la possibilità di aumentare il numero di animali allevati per unità di superficie disponibile per lo smaltimento del letame, o di ridurre i costi di alimentazione a causa di un minor uso di costose fonti proteiche. I risultati del terzo contributo indicano che il metodo di preparazione del campione ha un'influenza sul profilo di acidi grassi delle feci, ed in particolare sulla componente dei CLA, maggiore rispetto a quella precedentemente evidenziata in letteratura che indicava la metilazione come tappa critica per un'analisi accurata degli acidi grassi mediante gascromatografia. L’individuazione di metodi di analisi applicabili a differenti substrati biologici (foraggi e alimenti, feci e prodotti di origine animale) è necessaria per migliorare le conoscenze sulla digestione dei lipidi ed il metabolismo degli animali da allevamento.

Com o objetivo de avaliar a substituição de uma fonte de proteína verdadeira (farelo de soja; dieta deficiente em PDR), por uréia ou amiréia (A-150S - fonte de nitrogênio não protéico de suposta liberação gradativa de nitrogênio; dietas adequadas em PDR), foram realizados três experimentos. Experimento I: Seis machos da raça Nelore, não castrados, com peso médio inicial de 420 kg, foram utilizados em quadrado latino 3x3 duplicado, avaliando-se: a digestibilidade, o balanço de nitrogênio, parâmetros ruminais e sanguíneos (capítulo 3); a estimativa da digestibilidade no trato gastrintestinal utilizando indicadores externo e internos comparados com colheita total de fezes (capítulo 6). O volumoso utilizado foi o BIN (20% da MS). A digestibilidade da MS, MO, CNF, EE, PB e o NDT não diferiram (P>0,05) entre os tratamentos. A digestibilidade da FDA e FDN foram superiores (P<0,05) nos tratamentos uréia e amiréia. Não houve efeito de tratamento e da interação tratamento x horários (P>0,05) nos valores de pH, AGV total, acetato, propionato, butirato e relação acetato:propionato do fluido ruminal. A concentração de nitrogênio amoniacal no fluido ruminal foi superior (P<0,05) no tratamento com uréia, comparado ao tratamento com farelo de soja, sendo similar aos dois, o tratamento com amiréia. O tratamento com amiréia apresentou maior (P<0,05) perda de N na urina. A retenção de N e o valor biológico da proteína foram superiores (P<0,05) para o tratamento com uréia, comparado aos demais. A concentração de nitrogênio uréico no plasma e a concentração de glicose plasmática foram similares (P>0,05) entre os tratamentos. A estimativa da digestibilidade utilizando o óxido de cromo apresentou resultados similares (P>0,05) à colheita total de fezes. O mesmo foi observado com a lignina no tratamento deficiente em PDR (FS), mas nos de uréia e amiréia, os coeficientes de digestibilidade foram subestimados (P<0,05). A FDNi subestimou (P<0,05) a estimativa da digestibilidade em todas as frações independente do tratamento. A fluorescência de raios-X demonstrou ser uma técnica promissora de análise do cromo (capítulo 6). Experimento II: oitenta e um machos não castrados em crescimento foram utilizados em um delineamento experimental de blocos ao acaso com três tratamentos, tendo três animais por baia e nove baias por tratamento, com a mesma dieta anterior, para avaliar o desempenho dos animais (capítulo 4). O tratamento FS apresentou menor consumo e ganho de peso (P<0,01) e pior (P<0,01) conversão alimentar. Os tratamentos uréia e A-150S não diferiram (P>0,05) entre si. Experimento III: realizou-se outro experimento de desempenho similar ao anterior, utilizando-se apenas outro volumoso (45% de BTPV e 5% de BIN) e os animais estavam na fase de terminação (capitulo 5). O tratamento FS apresentou maior (P<0,01) consumo e ganho de peso e melhor conversão alimentar do que os tratamentos uréia e A-150S. Os tratamentos uréia e A-150S não diferiram (P>0,05) entre si. A amiréia promoveu resultados similares a uréia convencional no consumo dos nutrientes, digestibilidade, parâmetros ruminais e sanguíneos e no desempenho de bovinos de corte confinados.<br>Experiment I: Six Nellore bulls, with 420 kg of body weight, were used to evaluate the replacement of a true protein source (soybean meal-SBM), in an inadequate RDP diet, by urea or starea (non protein nitrogen source supposedly of slow N release), being the last two N sources in an adequate RDP diet. Sugar cane bagasse in natura (BIN) was the only source of diet forage (20% of DM). This trial evaluated: digestibility, ruminal parameters, ruminal ammonia, blood parameters and N balance (chapter 3); total tract digestibility estimated by using internal and external markers compared to total feces collection (chapter 6). DM, OM, NFC, EE, CP and TDN digestibilities (%) did not differ (P>0.05) among treatments. ADF and NDF digestibilities (%) were higher (P<0.05) for urea and starea treatments. There was no treatment or treatment X time effect (P>0.05) on pH, total VFA, acetate, propionate, butirate and acetate:propionate ratio. Ruminal ammonia N concentration was greater (P<0.05) for urea compared to soybean meal and starea was similar to both. Starea treatment had the higher (P>0.05) urinary N loss. N retention (g/d and % of ingested) and protein biological value (N retention, % of N digestible) were higher (P<0.05) for urea treatment. Plasma urea nitrogen and glucose concentrations were similar (P>0.05) among treatment (chapter 3). The digestibility estimated by using cromium oxide was similar (P>0.05) to that of using total feces collection. Lignin used as an internal marker resulted in similar pattern as feces collection when the diet contained soybean meal (RDP deficient diet), however, when the diet N was urea or starea, the digestibility coefficients were underestimated (P<0.05). The NDFi underestimated (P<0.05) the digestibility of all portion independent of treatment. X-ray fluorescence showed be a promising technique for cromium determination (chapter 6). Experiment II: Eighty-one growing intact males were used in a totally random block design, with three treatments (three animals/pen and nine pens/treatment) to evaluate beef cattle performance in feedlot (chapter 4). Diets were the same used in Exp. I. DM intake, ADG and feed conversion were 6.56, 7.18 and 6.97 kg/day; 0.889, 1.114 and 1.088 kg/day and 7.3, 6.5 and 6.7 kg DM/kg gain, for SBM, urea and starea, respectively. SBM treatment had the smaller (P<0.01) DM intake, ADG and feed conversion. Urea and starea treatment were similar (P>0.05). Experiment III: Another performance trial was done (chapter 5), similar to Exp. II, differing only by the forage portion of the diet (45% hidrolized sugar cane bagasse-BTPV and 5% bagasse in natura–BIN) for finishing cattle. DM intake, ADG and feed conversion were 8.99, 7.43 and 7.69 kg/day; 0.983, 0.368 and 0.404 kg/day and 9.56, 20.14 and 19.54 kg DM/kg gain for SBM, urea and starea treatments, respectively. SBM had the higher (P<0.01) DM intake and ADG and better feed conversion compared to urea and starea. Urea and starea treatments were similar (P>0.05). Starea showed similar results to urea.

Studies the growth, body composition, feed intake of grazing animals, the use of anabolic agents, fatty acid composition of ruminants fats; and, the effect of saturated fat on human health.<br>Thesis (M.Ag.Sc.) -- University of Adelaide, Dept. of Animal Sciences, 1989

The "In Sacco" technique and the Mobile Nylon Bag Technique were used to compare canola meal (CM) and soybean meal (SBM) with respect to rumen escape and lower digestive tract digestibility of dry matter, protein, energy, and essential amino acids (EAA). A sample of CM was obtained from five different processors and designated A, B, C, D, and E. A SBM sample was obtained from a processor in Altona, Manitoba, and designated F. Two rumen cannulated Holstein steers and three duodenally cannulated Holstein steers were used. Small nylon bags, 3 cm x 5 cm, containing .5 g of sample, were incubated in the rumen for various time intervals, then removed. Half of the bags removed were analyzed for rumen effects, the other half were then incubated in pepsin-HC1 solution for 3 hrs at 39o C, to simulate abomasal digestion. The bags were then passed through the lower digestive tract of the duodenally cannulated steers, subsequently collected in the feces, and analyzed. Six trials were carried out with the rumen incubation periods as follows: 0 h; 4 h; 8 h; 12 h; 16 h; 30 h. The data obtained showed that the N escape values of SBM in the rumen fall within the range of values obtained for CM. The data obtained showed that the DM escape of SBM is less than CM at 30 h, but at the other time intervals it falls within the range of values obtained for CM. The data obtained showed that energy escape from the rumen for SBM is higher than that of CM at 4 and 16 h, but at 8, 12, and 30 h, it is similar to the values obtained from some of the CM samples. The data obtained showed that EAA escape of SBM falls in the range of values obtained for CM at all time intervals, except for: His at 4 h; Met at 12 h; Met at 16 h. The digestibility data obtained showed that N, DM, and energy digestibility from SBM is greater than from CM. These data suggest that all EAA had digestibilities that were greater from SBM than from CM in the lower digestive tract, except: Met at 0 h; Met at 4 h; Lys His Val Thr Ile Leu and Met at 8 h; Lys His Phe and Met at 12 h; all EAA at 16 h. In general these data suggest that CM and SBM samples were not different with respect to rumen escape of dry matter, protein, energy and essential amino acids. However, these data suggest that lower digestive tract nutrient digestibility from SBM is greater than CM.

As a continuing effort to increase the level of rumen escape protein and post ruminially available amino acids (AA) in high producing ruminants of today such as dairy cows in early lactation, three trials were conducted using three non-lactating Holstein cows fitted with rumen and T-shape proximal duodenal canulae; fifty adults Single Comb White Leghorn cockerels; and thirty two lactating cows. The purpose was to determine the effect of moist heat treatment of canola meal (CM) as a source of rumen escape protein as measured from in situ rumen and lower gastro intestinal (GI) tract degradability of: dry matter (DM), fiber, protein, essential (EAA) and non essential (NEAA); availability of EAA, NEAA and true nitrogen-corrected metabilizable energy (TMEn) in precision-fed cockerels; and feed intake, milk production, milk composition and body weight change in dairy cows in early lactation. Four different batches of commercial CM were exposed to moist heating at 110oC for 0 (CM 0), 23 (CM 23), 45 (CM 45) and 60 (CM 60) min through a steam jacketed conveyor and slowly steeped at passage rates of 200, 110 and 90 kg h-1 respectively. A bypass protein supplement (Bi) made from a mixture of animal-vegetable products was formulated for comparison with CM 60, based on similar calculated rumen escape EAA... (P<0.05) neutral detergent fibre (NDF), acid detergent insoluable nitrogen (ADIN) and neutral detergent insoluble nitogen (NDIN) contents. Rumen degradation of protein from CM 0 was higher (P<0.05) than other levels of heat treated CM. Type of protein in cows' diet affected (P<0.05) rumen protein degradation and subsequent rumen disappearance of nitrogen. Protein and EAA degradation was higher (P<0.05) in monofilament bag type than multifilament type. Lower GI tract degradation of protein from both bag types was not affected (P<0.05) by removal of pepsin-HCI digestion step. Heat treatment did not (P<0.05) change individual EAA and NEAA but tended to decrease (P<0.05) fecal excretion of arginine, leucine, lysine, methionine, and valine. Disappearance of EAA 12 h post rumen incubation was reduced (P<0.05) in the rumen but increased (P<0.05) in the lower GI tract with 60 min heat treatment and resulted in increased (P<0.05) fecal excretion of arginine, histidine, isoleucine, lysine, methionine and threonine. These changes resulted in an increased (P<0.05) 80-90% available EAA quantity in the small intestine... Results from these trials indicated decreased (P<0.05) rumen degradation of CM with increased heating, resulting in higher levels of protein and AA availability post-ruminally. Although the potential for rumen escape of heat treated CM increased P<0.05), milk yield and composition did not differ (P<0.05) from the unheated CM> It is suggested that higher temperatues above 110oC or longer heating times than 60 min be adopted with continued use of CM in dairy rations.

Three experiments compared ruminal, physiological, and performance responses of beef steers consuming hay ad libitum and receiving grain-based supplements with (CAM) or without (CO) inclusion of camelina meal. In Exp. 1, 9 steers fitted with ruminal cannulas received CAM (2.04 kg of DM/d) or CO (2.20 kg of DM/d). Steers receiving CAM had reduced (P = 0.01) total DMI and tended to have reduced (P = 0.10) forage DMI compared to CO. No treatment effects were detected (P ≥ 0.35) for ruminal hay degradability parameters. In Exp. 2, 14 steers receiving CAM (1.52 kg of DM/d) or CO (1.65 kg of DM/d) were assigned to corticotropin-releasing hormone (CRH; 0.1 μg/kg of BW) and thyrotropin-releasing hormone (TRH; 0.33 μg/kg of BW) challenges. Steers receiving CAM had greater (P < 0.05) serum concentrations of PUFA compared to CO prior to challenges. Upon CRH infusion, mean plasma ceruloplasmin concentrations increased at a lesser rate in CAM compared with CO (P < 0.01). Upon TRH infusion, no treatment effects were detected (P ≥ 0.55) for serum TSH, T₃, and T₄. In Exp. 3, 60 steers were allocated to 20 drylot pens. Pens were randomly assigned to receive CAM (2.04 kg of DM/steer daily) or CO (2.20 kg of DM/steer daily) during preconditioning (PC; d -28 to 0). On the morning of d 0, steers were transported for 24 h. Upon arrival from transport on d 1, pens were randomly assigned to receive, in a 2 x 2 factorial arrangement, CAM or CO during feedlot receiving (FR; d 1 to 29). During PC, CAM had reduced (P < 0.01) forage and total DMI, and tended to have reduced (P = 0.10) ADG compared to CO. Plasma linolenic acid concentrations increased during PC for CAM, but not for CO (P = 0.02). Steers that received CAM during FR had greater (P < 0.05) mean plasma concentrations of PUFA, and reduced mean rectal temperature and concentrations of haptoglobin and ceruloplasmin during FR compared to CO. Therefore, camelina supplementation reduced forage and total DMI, did not alter thyroid gland function, increased PUFA concentrations in blood, and attenuated the acute-phase protein reaction elicited by neuroendocrine stress responses. In conclusion, camelina meal is a feasible ingredient to reduce stress-induced inflammatory reactions and potentially promote cattle welfare and productivity in beef operations.<br>Graduation date: 2012

The current research was done to evaluate the nutritive values and the ruminal degradation of dry matter (DM) and crude protein (CP) from three non-conventional oil cakes, viz: amarula (Sclerocarya birrea) (AOC), macadamia (Integrifolia) (MOC) and baobab (Adansonia digitate L.) (BOC). The oil cakes were collected from biodiesel producers in Limpopo Province, transported to the ARC-Animal Production campus, where proximate and ruminal nutrient degradation analysis were conducted. Triplicates samples from each oil cake were analyzed for the nutritive values, mineral and amino acids contents. Three rumen cannulated mid-lactating (days in milk; DIM: 180±5) Holstein cows weighing 667±43 kg body weight were allocated to determine the in situ ruminal dry matter (DM) and crude protein (CP) degradation. The cows were offered a totally mixed ration (TMR) (60 concentrate: 40 forage ratio) that was compounded according to their daily nutrient requirements, and were milking was done twice per day at 12 hrs intervals. The three oil cake samples were ground using a 2-mm screen after which sub-samples (6.5 g) were put in 10 x 20 cm; 50 μm pore size polyester bags to achieve 15 mg/cm² (ratio of the sample size to surface area). The bags were then fistulated in each cow’s rumen in triplicate for a period of 2, 4, 8, 16, 24, or 48 hrs. After being incubated, the bags were removed from the rumen and washed with cold (4°C) water in 20-L buckets. Following immersing in cold water, the bags were machine washed until clean water was obtained. The bags were then dried at 60 °C in an oven for 48 hrs. The dried bags were individually weighed, and the content of each bag were removed and stored into glass vial until analysis. The remaining two duplicate sets of each sample were rinsed using cold water in order to determine solubility at 0 hrs. The AOC had higher (P<0.05) ether extract (EE) and CP content than both BOC and MOC. Macadamia oilcake (MOC) and BOC had higher (P<0.05) fractions of fibre (NDF, ADF and ADL) compared to the AOC. The AOC had greater (P<0.05) content of essential amino acids than in the BOC and MOC. Additionally, AOC had a high (P<0.05) phosphorus, but low calcium and potassium concentration. While AOC had high effective degradability of DM, it also had high water soluble as well as DM and CP rapidly degradable fractions. Effective degradation of CP was higher in AOC and BOC than in MOC. However, BOC had a high insoluble but degradable fraction of CP. Further work to determine the toxicology of these non-conventional oil cakes and animal feeding experiments is needed<br>Agriculture and  Animal Health<br>MSc. Agriculture

Orientação: Sofia Van Harten<br>Nos sistemas intensivos de produção de carne bovina, a manipulação dietética com aditivos torna-se uma ferramenta indispensável na prevenção de certas doenças, nomeadamente acidose ruminal e ruminite. Assim, surge a necessidade de averiguar quais os melhores aditivos, tanto para o produtor como para a saúde dos animais. Neste trabalho estudou-se o efeito da suplementação com leveduras vivas e com fontes lipídicas sobre a saúde ruminal e o desempenho de bovinos Nelore em feedlot, durante 109 dias. Foi feita a distribuição aleatória dos animais (n=133; 372Kg) em três grupos: controlo (n=20) sem aditivos, leveduras vivas (n=17) suplementado com Saccharomyces cerevisiae e lipídico (n=96) suplementado com uma fonte de lípidos. Após o ensaio, o epitélio ruminal foi classificado quanto à incidência e ao nível de lesões e as papilas foram analisadas histológicamente. A flutuação da IMS e o peso ganho também foram determinados. O grupo lipídico apesar de ter apresentado maior flutuação da IMS, ganhou mais peso (25,4%). A inclusão de leveduras não diferiu do controlo e gerou uma IMS diária mais constante. Contudo, este resultado não se traduziu num maior ganho de peso, reforçando a evidência inconclusiva dos benefícios das leveduras. Em relação à saúde ruminal, os bovinos com suplementação de lípidos obtiveram maior área média de papilas, maior participação das mesmas na área absortiva e maior índice mitótico. Todos os grupos apresentaram ruminite, porém o seu índice não diferiu entre eles (p=0,725) e visto que foi inferior a 2, não ocorreu acidose ruminal. Este trabalho pode reforçar o conceito da suplementação lipídica nas dietas do gado de engorda, devido ao maior ganho de peso e ao baixo nível de ruminite.<br>In intensive beef production systems, dietary manipulation with additives becomes an indispensable tool in the prevention of certain diseases, namely ruminal acidosis and consequently rumenitis. Thus, there is a need to investigate the best additives, both for the producer and for animals health. The objective of this work was to study the effect of supplementation with live yeasts and lipid sources on ruminal health and performance of Nellore cattle in feedlot. In an experimental period of 109 days, the animals (n= 133; 372kg) were randomly distributed into three groups: Control (n=20) fed without any additives, live yeast supplemented (n=17) fed with Saccharomyces cerevisiae and lipidic (n=96), fed with a lipid source. First, ruminal epithelium was classified according to incidence and level of lesions, then papillae were morphologically and histologically analyzed. DMI fluctuation and weight gain were also determined. The lipid group, despite of having a greater DMI fluctuation, gained more weight (25.4%). The inclusion of live yeasts in the diet generated a more constant daily DMI. However, this result didn’t translate into greater weight gain, reinforcing inconclusive evidence of yeast benefits. Regarding ruminal health, the cattle of the lipid group had the highest mean area of papillae and greater participation of the ruminal papillae in the absorptive area and higher mitotic index. All groups presented rumenitis, but index did not differ between them (p = 0,725) and it was less than 2, so there was no ruminal acidosis. This work can reinforce the concept of a lipid supplementation in feedlot cattle diets, due to a higher weight gain and a low level of ruminal acidosis.

The objective of this study was to examine the effects of feeding extruded and non-extruded mixtures of wheat dried distillers grains with solubles with peas (WP) or canola meal (WC) on ruminal fermentation, total tract nutrient digestion and milk production in dairy cows. Eight dairy cows (712 ± 54 kg body weight; 90 ± 31 days-in-milk at the beginning of the experiment) were used in a replicated 4 × 4 Latin square design (28-d periods) with a 2 × 2 factorial arrangement of dietary treatments. Four cows in one Latin square were fitted with rumen cannulas for the measurement of ruminal fermentation characteristics. Treatment diets contained either WP or WC combinations fed in an extruded or non-extruded form (16% of DMI). Diets were isonitrogenous (17.1% crude protein; CP) and contained approximately 53% concentrate and 47% forage (DM basis). Dietary treatment had no significant effect on DMI (P > 0.10). Starch intake was higher for cows fed extruded diets compared to those fed non-extruded diets (P = 0.028) and was also higher for cows fed WP compared to those fed WC (P = 0.042). Cows fed extruded diets had higher apparent ruminal digestion of DM (P = 0.02) and a tendency (P = 0.05) for a higher OM apparently digested in the rumen compared to those fed non-extruded diets. Total tract digestibilities of organic matter (P < 0.01), CP (P < 0.01), ether extract (P < 0.01) and starch (P = 0.047) were higher for cows fed extruded diets compared to those fed non-extruded diets. Total tract digestibility of ether extract was lower (P = 0.011) but digestibility of starch was higher (P < 0.01) and CP digestibility tended to be higher (P = 0.08) for cows fed WP compared to those fed WC. Fecal N excretion was lower in cows fed extruded diets compared to those fed non-extruded diets (P < 0.01), but there was no difference in N retention, productive N, RDP or RUP between diets (P > 0.10). Ruminal pH was higher for cows fed non-extruded WC compared to those fed extruded WC, but there was no difference between WP diets (interaction; P = 0.047). Ruminal acetate displayed the opposite interaction where concentration was highest for cows fed extruded WC and lowest for those fed non-extruded WC but there was no difference between WP diets (interaction; P = 0.019). Ruminal ammonia-N concentration tended to be higher for cows fed WC compared to those fed WP (P = 0.06). Ruminal propionate concentration was higher for cows fed extruded diets compare to those fed non-extruded diets (P = 0.026). Ruminal isobutyrate concentration was higher for cows fed WC compared to those fed WP (P < 0.01). Ruminal butyrate (P < 0.01) and isovalerate (P < 0.01) concentrations were higher for cows fed extruded WC compared to those fed non-extruded WC, but concentrations decreased for cows fed extruded WP compared to those fed non-extruded WP. Plasma glucose concentration was higher for cows fed WC compared to those fed WP but concentration was highest for cows fed extruded WC but lowest for cows fed extruded WP (interaction; P < 0.01). Milk protein yield (P = 0.047) was higher and milk yield tended to be higher (P = 0.06) for cows fed WP compared to those fed WC diets. Milk protein content was not affected by diet; however, milk fat content (P = 0.04) and MUN (P = 0.011) were lower, whereas milk yield (P = 0.030), 3.5% fat corrected milk yield (P = 0.027), milk fat yield (P = 0.027), lactose content (P = 0.011) and lactose yield (P < 0.01) were higher in cows fed the extruded diets compared to those fed non-extruded diets. In summary, these results indicate that extrusion had positive effects on overall milk production and total tract nutrient digestion.