Dissertations / Theses on the topic 'Animal nutrition'

This dissertation focuses on the impact of nutrition to modulate and optimize milk production, blood metabolites and liver metabolism. Specifically, the main aim was to elucidate the effects of rumen protected choline (RPC) supplementation to lactating dairy cows on production, metabolic health and hepatic gene expression, for which two different studies were performed. The first study, a meta-analysis of the effect of RPC supplementation on milk yield (MY), nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHBA) in lactating dairy cows was performed in order to obtain an overall view of the effect of rumen protected choline. Rumen protected choline supplementation has been reported to have a positive effect on milk yield and metabolic health in lactating dairy cows. In light of this, a meta-analysis has been performed in order to elucidate the effect of choline chloride supplemented as RPC on both milk yield and selected blood metabolites. For this purpose, 21 peer-reviewed articles published from 1985 to 2016 were selected. This systematic review was carried out to evaluate the effects of RPC supplementation on MY, NEFA, and BHBA. Results obtained showed positive effects of RPC supplementation on MY in lactating dairy cows. The studies selected for this meta- analysis supplemented choline chloride in a range from 6.25 to 50g/d and milk production increase averaged 2.14±1.86 kg/d. Meta-regression on the dose- response relationship between dietary RPC and MY was significant. When NEFA and BHBA were evaluated, no overall effect was detected. Moderator analysis revealed that all outcomes, MY, NEFA and BHBA, were not significantly affected by the mode of choline supplementation (blended vs. topdressed). In the second study, the mechanism beyond the metabolic changes due to RPC was investigated, with emphasis on hepatic gluconeogenesis, lipid oxidation and transport that occur during the transition period; particularly, the interaction of RPC and dietary energy concentration was tested and the expression of selected hepatic genes was analyzed. Hepatic gluconeogenic and oxidation genes were studied during the transition from late pregnancy to early lactation dependent upon RPC supplementation during the periparturient period, and prepartum energy intake. Controlling prepartum energy intake or supplementing RPC during the periparturient period, are two strategies to optimize hepatic metabolic function. At -48 days relative to calving (DRTC), multiparous Holstein cows were assigned to either a controlled (1.40 Mcal of NEL/kg DM; CE) or high (1.63 Mcal NEL/kg DM; HE) energy prepartum diet with or without RPC (top-dressed daily from -21 to +21 DRTC). Postpartum diets only differed in addition vs absence of RPC. Liver tissue biopsy samples were collected at -14, +7, +14, and +21 DRTC for RNA isolation and cDNA generation (n=16/treatment). Six genes involved in gluconeogenesis, lipid oxidation and lipid transportation were selected. Results obtained indicate that an increase in the expression of pyruvate carboxylase mRNA was reduced in cows receiving RPC after calving, which suggests that RPC had improved energy status and carbohydrate metabolism in the liver and reduced the need for pyruvate carboxylase. RPC supplementation decreased PCK1 in HE+RPC probably due to higher oxidation of increased circulating NEFA that translated to increased oxidative capacity of the TCA cycle. Moreover, this change can help to maintain the oxaloacetate pool. No effect of RPC supplementation was observed with regard to CPT1A, which is involved in fatty acid transportation. On the other hand, PPARA and MTTP were affected by RPC treatment, indicating that RPC supplementation may have modulated FA transport and oxidation. In light of the two studies performed, RPC can improve milk production through lactation. Additionally, RPC supplementation may support and increase hepatic oxidative capacity.

The main objective of this thesis was to have a deeper knowledge about the influence of feeding strategies with several natural plants extracts on pig performance and meat quality in different phases of pig production. To achieve this objective, a set of 4 studies were performed (chapter 2-6). The first study evaluated the effect of dietary supplementation with a mixture of algae plus polyphenols (AM) in lactating sow on maternal and piglets performance and sows reproductive data until the subsequent farrowing. This study showed that integration of AM in sow diet decreased the fat mobilization during lactation. Moreover, dietary AM inclusion in lactating sows positively affected body weight and average daily gain in piglets at 21 days. Moreover, sows that received AM had more total number of piglets born at the subsequent farrowing. Regarding the effects of plant extracts on meat and product quality, two different studies were performed. In the second study of the thesis, the impact of dietary integration with vitamin E and verbascoside (AOX) in pigs, on carcass characteristics, meat quality, shelf life of pork under modified atmosphere packaging (MAP) was evaluated. This study demonstrated the positive effects of plant extracts as antioxidant. Particularly, highlighted that dietary AOX positively affected carcass dressing percentage and pork oxidative and colour stability. Moreover, sensory analysis revealed that, at 15 days under MAP, meat from AOX was comparable with fresh meat in appearance and aroma. In the same way, the third study showed that vitamin E and verbascoside (AOX) also affected the quality of derived product like smoked cured ham. Results relieved infact that the AOX dietary inclusion affected the seasoning losses and influenced the consumers' preference of smoked cured ham, without affecting other quality parameters. Finally, the fourth experimental trial examined the impact of 3 % hydrolysable tannins (HT) from chestnut extract and two levels of polyunsaturated fatty acid (PUFA) in the diets on growth performance, carcass traits, meat quality and boar taint compounds in entire males. Results showed that dietary HT reduced the feed efficiency but not feed intake and the pigs final weight. These results show that performance, carcass composition and meat quality traits are not affected by dietary 3% chestnut extract supplementation in entire male. The boar taints compounds like androstenone, skatole and indole tended to be lower in HT group. The cytochrome mRNA expression in the liver and colon mucosa was not affected by the diet. No evident relationship between dietary PUFA level and boar taint compound levels was observed. Overall, these results contribute to improve the knowledge regarding beneficial effects of plant extracts. The inclusion of bioactive components contained in natural extracts can be considered an innovative approach to improve pig wellbeing and pork quality without negative effects on animal production.

The interaction effects of genotype and nutrition on the performance of sows during lactation is still poorly understood; this series of experiments explored the factors contributing to breed differences in lactational performance and the development of appropriate feeding strategies. Two extreme types of sow were used in these experiments; lean pure-bred White sows (W: Large White and Landrace) and a prolific but fatter Meishan synthetic damline (M: 50% Meishan genes). M sows had higher numbers of piglets, a different feed intake curve and produced more milk with a higher fat content compared to W breed types. Their response to dietary protein was different for the two breeds; the Meishan sows, with higher initial levels of body fat reserves, used the extra protein to increase milk production. The White sows did not partition the extra protein into milk but used it to conserve their own maternal body reserves and improved their weaning to conception interval. The breed differences in sows performance were found not to be solely due to differences in litter size or piglet genotype or maternal body fat reserves. M sows showed better maternal behaviour with lower activity and shorter suckling intervals. It can be concluded from these experiments that Meishan synthetic sows are inherently better mothers, and the way in which sows of different breed types partition feed nutrients during lactation is very different. A dietary lysine concentration of 9 g/kg (giving daily intakes of 53-61 g/day at 98-111 MJ DE/day) optimised lactational and rebreeding performance in both breed types.

The influence of animal nutrition on meat quality Sabrina Ratti Abstract: Food and Agriculture organization of the United Nations (FAO) define meat quality as compositional quality and palatability factors such as visual appearance, smell, firmness, juiciness, tenderness, and flavour. Recently, the attention has been focused on the improvement of meat quality parameters. The protection of lipids from oxidative phenomena is fundamental to preserve meat color, nutritional quality and increase shelf life, enhancing consumer acceptability. Otherwise, it is possible to enhance nutritional quality of meat and meat products, modifying fat content and fatty acid profile. Animal feeding is a key factor for improve meat quality parameters through dietary supplementation with different additives. Antioxidants are one of the major strategies for preventing lipid oxidation in meat products, decreasing oxidative phenomena and increasing shelf life. The search for safe and effective natural antioxidants has focused on plants extract. Dietary supplementation with antioxidant mixture containing polyphenols in swine, enhance color parameters and oxidative stability in Longissimus Dorsi muscle (trial 1 and 2). Moreover, the same plant extract improved oxidative stability and sensory parameter in donkey and horse Longissimus Lomborum muscle (trial 3). Also genetic type significantly affects cooked ham chemical profile, without affecting other quality parameters (trial 4). Nutritional quality of pork products are improved by dietary linseed supplementation, enhancing muscle and adipose tissue n-3 PUFA content. Meta-analysis data provides information to find the optimal dosage, source and length of linseed dietary supplementation in relation to slaughter weight and genetic type (trial 5). Our results point out the importance of animal dietary supplementation with plant extract and linseed, on oxidative stability, physical, chemical and sensory parameters of different type of meat and meat product.

Bibliography: leaves 186-200. Analyses feed intake and growth data from cattle, which indicates that genetic variation exists in post-weaning effiency and growth. Concludes with a consideration of how post-weaning feed intake information can be used in genetic improvement programs.

Nutrition plays an important role in maintaining a good health status of animals as nutrients can modulate oxidative status, immune and inflammatory response. Moreover, there is a need of innovative additives and feeds that can improve organism defences against diseases. The aim of this work was to monitor different markers of oxidative stress and inflammation in production animals in response to different feed additives. In this study, first, the activation of Nuclear factor-E2 related factor 2 in transgenic mice fed different sources and amount of fatty acids was monitored. Inducing the transcription of genes involved in oxidative stress response, Nrf2 represents one of the main actor in the organism defence against oxidative stress. In this phase, we used an innovative technique of in vivo imaging that allowed us to follow the experimental subject in time and in vivo. reducing significantly animal stress. Secondly, an evaluation of different oxidative and inflammatory markers was carried on post-weaning piglets fed with melon pulp concentrate. The double aim of this trial was to validate melon pulp concentrate as a feed additives to improve immune response in challenged pigs and to monitor the trends of commonly used markers during LPS challenge. Then, as the effectiveness of new feed additives are under investigation and their effect on intestinal health need to be demonstrated, is essential to turn attention to intestinal health biomarkers, non- or minimally invasive. For this reason, the main aim of the last study was to develop and validate a new sandwich ELISA test for the quantification of Pacreatitis Associated Protein in pig faecal samples. Finally, an observational study on a new Oxidative Stress Index (OSi) was conducted on dairy cows during the transition period. The driving hypothesis was that a composed index, as OSi, predicts more accurately the oxidative status than the evaluation of reactive oxygen species or serum antioxidant capacity separately. Furthermore, the relationship between indexes of oxidative status and markers of energy balance as blood free fatty acids and β-hydroxybutyrate, was determined.

11 pp.
This publication contains information about browse utilization by ruminant animals. It provides information about the rangelands in Arizona, the nutritional quality of browse, effects of drought and tannin and how to overcome them.

Lo scopo della presente ricerca è stato quello di valutare degli effetti della somministrazione di differenti fonti di acidi grassi sulla salute animale e sulla qualità dei prodotti derivati; non di meno, sono stati oggetto di analisi i possibili effetti benefici sulla salute umana. A tale scopo, sono state effettuate due distinte prove sperimentali, una su capre da latte e l’altra su galline ovaiole. La prima prova ha preso in considerazione lo studio dell’espressione di geni e miRNA coinvolti nel metabolismo lipidico e nel processo infiammatorio a livello di tessuto epatico e adiposo sottocutaneo di nella capra da latte in transizione a seguito della somministrazione di fonti grassate apportanti acidi grassi saturi (SFA) o polinsaturi (PUFA) della serie omega 3 e 6 quali acido stearico e olio di pesce. La seconda sperimentazione ha preso in considerazione le performance e la qualità dell’uovo prodotto in galline ovaiole la cui dieta è stata supplementata con Camelina sativa. Negli ultimi decenni l’integrazione della dieta con PUFA, in particolare con l’acido eicosapentaenoico (EPA) e docosaesaenoico (DHA), si è dimostrata efficace in termini di salute sia a livello animale, attraverso la modulazione del metabolismo e del sistema immunitario, sia a livello dell’uomo, con il consumo di alimenti animali arricchiti di acidi grassi essenziali. Il primo caso di studio ha preso in esame 23 capre da latte di razza Alpina diagnosticate per un parto gemellare. La sperimentazione ha previsto l’integrazione della dieta da una settimana prima (30 g/head/d di acidi grassi) a tre settimane dopo il parto (50 g/head/d di acidi grassi) di calcio stearato (ST, n= 7) o olio di pesce (FO, n= 8), e il confronto di questi due gruppi sperimentali con un gruppo di controllo (CON, n= 8), alimentato con una dieta base. Sono state effettuate biopsie di fegato e tessuto adiposo sottocutaneo a -7, 7 e 21 giorni dal parto al fine di determinare l’espressione mRNA e miRNA di 38 geni implicati nel metabolismo lipidico di fegato e tessuto adipose e nella risposta infiammatoria a livello adiposo, mediante Polymerase Chain Reaction (PCR). Ad eccezione di Stearoyl-CoA desaturasi (SCD) (fegato), non abbiamo riscontrato variazioni significative nell’espressione dei geni oggetto di studio a seguito della somministrazione dei trattamenti (FO e ST). Specificatamente, la supplementazione lipidica ha portato ad un aumento dell’espressione di SCD nel gruppo ST e una riduzione nel FO. L’effetto del tempo ha influenzato l’andamento della maggior parte dei geni target per il metabolismo lipidico del fegato, vedendone l’espressione aumentata da -7 a 7 giorni di lattazione e ridotta nella terza settimana di lattazione mentre, a livello di tessuto adiposo, è stata osservata una down regulation per tutta la durata della prova. Per quanto riguarda l’andamento dell’espressione dei geni implicati nei fenomeni di infiammazione nel tessuto adiposo, i risultati del presente studio hanno evidenziato una up-regulation delle proteine di fase acuta nelle due settimane in prossimità del parto, diminuita poi da 7 a 21 giorni di lattazione. Le interleuchine pro-infiammatorie (IL6 and IL8) hanno raggiunto un picco nella prima settimana dopo il parto, mentre abbiamo osservato una up-regulation di IL10 nelle ultime due settimane di prova. Considerando i microRNA, ad eccezione dell’aumento dell’espressione del miR-155 da -7 a 7 die dal parto, non è stato osservato nessun effetto del tempo. Analizzando l’effetto interazione dieta*tempo nel metabolismo del fegato, Acyl-CoA Ossidasi 1 (ACOX1) ha visto aumentata la sua espressione nel gruppo ST, rispetto al CON al giorno 7 mentre SCD ha evidenziato una maggiore espressione da 7 a 21 giorni nel gruppo ST, se comparato al gruppo FO. Passando poi al tessuto adiposo, Lipin1 (LPIN1) ha mostrato valori di espressione maggiori per il FO a 7 giorni di lattazione (rispetto a ST) e l’espressione di FASN ha raggiunto valori più elevati nel gruppo stearato a -7 DIM rispetto al controllo e al FO. L’espressione di IL6 nel tessuto adiposo ha mostrato una down-regulation nel gruppo stearato rispetto al gruppo controllo al giorno 7. Il presente studio ha evidenziato limitati effetti dell’espressione dei geni considerati, coinvolti nel metabolismo lipidico e nell’infiammazione in fegato e tessuto adiposo, a seguito dell’integrazione di acidi grassi saturi e polinsaturi in capre da latte vicine al parto. Nel contempo, è stato osservato un trend fisiologico nelle due settimane in prossimità del parto, caratterizzato da un aumento della β-ossidazione nel fegato e da una diminuzione nella sintesi di acidi grassi, accompagnata da più intensi processi infiammatori, a livello di tessuto adiposo. La successiva prova sperimentale si svolta con un numero totale di 32 galline ovaiole, assegnate in modo casuale a due gruppi oggetto di studio, con otto replicati per gruppo. Gli animali sono stati alimentati con una dieta base con (T) o senza (C) l’inclusione del 7.5% di farina di camelina per un totale di 63 giorni. Le performance degli animali sono state valutate settimanalmente, mentre la qualità dell’uovo è stata determinata a 0, 28, 56 giorni e la shelf-life/TBARS a 0, 9, 21, 28 giorni. Si è visto come l’integrazione della farina di camelina abbia migliorato il tasso di conversione dell’alimento nelle galline (P<0.05). Inoltre, è stata osservata una riduzione del contenuto di acidi grassi saturi (SFA) nel tuorlo delle galline appartenenti al gruppo T (33.18 vs. 32.45 g/100g di acidi grassi totali; P˂ 0.01), concomitante ad un arricchimento in acido α-linolenico (1.05 vs. 1.47 g/100g di acidi grassi totali; P< 0.01). I risultati così ottenuti mostrano come sia possibile, integrando la dieta di galline ovaiole con farina di Camelina sativa, migliorare la qualità del tuorlo, agendo sulla riduzione del contenuto in SFA e apportando un aumento di acidi grassi essenziali n-3. Ne consegue che i PUFA possano avere un duplice impatto: sulla salute animale e, indirettamente, sulla salute del consumatore. Infatti, questi acidi grassi non solo si sono dimostrati essere una fonte energetica ma anche una valida integrazione alla dieta animale durante i periodi più stressanti, quale, ad esempio il periparto. Di conseguenza, questo tipo di strategie alimentari possono agire su due fronti: da un lato migliorare la composizione acidica dei prodotti di origine animale, con un decremento nel contenuto di SFA e un aumento di acidi grassi monoinsaturi (MUFA) e PUFA, e, dall’altro, arricchire la dieta del consumatore.
The aim of the present thesis is to evaluate the effects of different dietary fatty acid sources on animal health and product quality, in addition, the possible beneficial effects on human health from animal product consumption was also a central motivation for this evaluation. With this purpose, two different trials were performed in dairy goats and laying hens respectively. Accounted for, were: (i) The expression of selected lipid metabolism and inflammation-related genes, and miRNA in the liver and adipose tissue of small ruminants around kidding which were fed saturated (SFA) or polyunsaturated (PUFA) fatty acid supplements in their diets from stearic acid or fish oil, (ii) The performance and egg quality of laying hens fed PUFA from Camelina sativa dietary supply. In the last decades PUFA supply, especially EPA and DHA among others, was reported to be effective in both the improvement of animal health, through the modulation of the metabolism and immune systems, and the enrichment of animal products with essential fatty acids that can lead to positive effects on human health. The first trial considered twenty-three second-parity twin-diagnosed alpine dairy goats that were either fed from one week before (30 g/head/d fatty acids) to three weeks after kidding (50 g/head/d fatty acids) calcium stearate (ST, n= 7) or fish oil (FO, n= 8), and were compared to a control group fed a basal diet (CON, n= 8). Liver and adipose biopsies were collected on day -7, 7 and 21 from kidding. Quantitative PCR was used to measure mRNA and microRNA expression of 38 targets. Dietary treatments up-regulated (ST) and down-regulated (FO) Stearoyl-CoA desaturase (SCD) alone. Time around kidding strongly affected most of the target genes for lipid metabolism in liver, being mostly up-regulated from -7 to 7 DIM and down-regulated in the third week of lactation, while in adipose tissue a gradual down-regulation was observed throughout the trial. Acute-phase proteins were increased in adipose tissue in the two weeks around kidding and decreased from 7 to 21 DIM. Pro-inflammatory interleukins (IL6 and IL8) peaked in the first week after parturition, while IL10 was up-regulated in the last two weeks of the trial. With the exception of an up-regulation of miR-155 from -7 to 7 d from kidding, no effects of time were observed on miRNA expression in adipose tissue. Liver ACOX1 was greater in ST than CON on day 7 while SCD showed a higher expression from 7 to 21 DIM in ST compared to FO. Then, dealing with adipose tissue, LPIN1 had increase values in FO at 7 days after kidding (compared to ST) and FASN had the highest expression in stearate group 7 days before parturition, if compared to CON and FO. The expression of IL6 in adipose tissue had a down regulation in ST compared to control group at 7 DIM. The present trial revealed limited effects of dietary saturated or polyunsaturated supply around kidding on fatty acid metabolism - and inflammation - related genes in the liver and adipose tissue of dairy goats. At the same time, a physiological trend was observed in the two weeks around kidding with increased β-oxidation in the liver, and decreased fatty acid synthesis together with the higher inflammation processes in adipose tissue. The second trial involved a total number of 32 laying hens that were randomly allocated to two experimental groups, with eight replicates per group. Animals were fed a common basal diet with (T) or without (C) inclusion of 7.5% Camelina meal for a total period of 63 days. Performance was evaluated weekly, while egg quality was determined at days 0, 28, 56 and shelf-life/TBARS at days 0, 9, 21, 28. Camelina meal supplementation improved feed conversion rate in laying hens (P<0.05). Moreover, reduced saturated fatty acids (SFA) content was observed in the yolk of T hens (33.18 vs. 32.45 g/100g total fatty acids; P˂ 0.01), with a concomitant enrichment in α-linolenic acid (1.05 vs. 1.47 g/100g total fatty acids; P< 0.01). Results of the present study show that it is possible to improve yolk quality by feeding Camelina sativa meal to laying hens, reducing egg SFA content and providing increased amount of beneficial n-3 fatty acids. As a result, PUFA can exert a duplicate effect: on animal health and, indirectly, on human health. Indeed, they can act not just as a source of energy but also as an integral part of animal feed during stressing events such as peripartum. As a consequence, these nutritional strategies can also improve FA composition of animal products, with the decrease of SFA and increase of monounsaturated FA (MUFA) and PUFA contents, and a fortification of human diet.

The concentrations of calcium and phosphorus were determined in 12 llamas from the Condoriri Agricultural Experiment Center (Oruro Technical University) of Oruro, Bolivia during two seasons (wet and dry) and at three ages (newborn, juvenile, and adult). Samples of flesh were taken from the arm, leg, back, rib, and neck. Pasture samples (grassland and prairie) were used to determine the rate of biting of each animal studied. The blood samples were taken by extracting blood from a jugular vein. The minerals (Ca and P) in the flesh are highest in the wet season, 113.78 mg/100 g. The newborns were found to have the highest concentrations of minerals during the wet and dry season, 113.78 and 93.98 mg/100 g. The mineral concentrations of calcium and phosphorus for the newborns and adults were 120.58 and 144.5 mg/100 g. The lower concentration of juveniles had 7.52 mg/100 g of calcium in the meat and reported a 9.59 mg/100 g concentration during the wet season and 6.78 mg/100 g for the dry season. The juveniles and adults recorded higher concentrations of calcium with 9.2 and 8.78 mg/100 g with the newborns having a lower value of 6.58 mg/100 g. The phosphorus in the flesh was reported to be 9.59 mg/100 g for the wet season and 6.78 mg/100 g for the dry season. The concentration of the calcium and phosphorus in the grazed pasture during the wet and dry seasons was 0.56 and 0.12 % respectively. The females recorded higher concentrations of calcium and phosphorus with 0.38% while the males recorded only a 0.30% concentration. The calcium content is higher in the pasture (0.55%) than the phosphorus (0.13%). In the wet season the biomass contains 0.91% calcium and 0.22% phosphorus. During the dry season the high calcium content was 0.19% and for phosphorus it was 0.04%. The calcium and phosphorus exist in smaller quantities in the blood during the wet season (7.25 mg/dl) and greater quantities during the dry season (9.88 mg/dl). Juvenile females have a higher quantity of calcium (10.15 mg/dl) while newborns and adults have a lower quantity (9.52 and 7.2 mg/dl).

Thesis (Ph. D.)--University of Missouri-Columbia, 2006.
"May 2006" The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Vita. Includes bibliographical references.

Immunomodulatory nutrients as the omega-3 polyunsaturated fatty acids (n-3 PUFA) and citrus pectins (CPn) are reported to beneficially affect the host intestinal immunity. However so far, the biological pathways modulated by these nutrients in intestinal inflammation at the level of intestinal epithelial layer (IEL) remains elusive. To bridge this knowledge gap, the aim of our present study was set in the direction to delineate the effects of n-3 PUFA in porcine IPEC-J2 cell line under (LPS) stress conditions underpinning pig nutrition, combining the state-of-the-art cell-based assays and bioinformatic analysis. The second part of our study was directed towards establishing a primary intestinal epithelial cell (IEC) culture from chicken embryos for the assessment of CPn against LPS stress, underpinning poultry nutrition. Utilizing different cell-based assays, we have successfully demonstrated the proliferative effects of n-3 PUFAs as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the IPEC-J2 cells. Besides, n-3 PUFA pre-treatment (DHA:EPA, 1:2, 10 µM, 24 h) was shown to counteract the cellular damage elicited by different stress factors as LPS, hydrogen-peroxide (H2O2) and dextran sulphate sodium (DSS). In addition, through system biology and multi-omics integration (transcriptomics and proteomics), we have demonstrated the cytoprotective properties of n-3 PUFA in IPEC-J2 cells against LPS-induced inflammatory and metabolic damage. Specifically, in these cells, we have identified that n-3 PUFA regulate the biological process as, (i) Axon guidance for developmental process; (ii) Defensin and interferon-mediated antimicrobial defense response for homeostasis; (iii) Cell junction assembly under stress-related cell proliferation; (iv) Amelioration of TLR/MyD88 and cytokine signaling in innate immune response; (v) Fatty acid storage in lipid droplets for lipid homeostasis; (vi) Recovery of central carbon metabolic process from dysregulation under infection; (vii) Lipolysis of fatty acids stored in lipid droplets for prevention of cell starvation during infection. To the best of the knowledge, this is the first study to comprehensively map the bioactivity of n-3 PUFA in enterocytes using multi-omics approach. The outcome of the present study, will enable us to better understand the role of n-3 PUFA in intestinal barrier for planning nutritional or therapeutic strategies. Further in the chicken in vitro study, we have preliminarily demonstrated a simplified method of cell isolation and establishment of primary IEC culture from chicken embryos using mechanical tissue disruptions method. We have also shown that the response of chicken cells is in accordance with the reference IPEC-J2 line using a dose-response study with CPn and LPS. This primary IEC culture model can further be utilized as a starting point for setting up poultry in vitro studies on intestinal barrier.

The effect of a low-Cu diet supplied to gilts during pregnancy and early lactation on dams and their offspring was obtained in seven pairs of first littermate gilts. They were housed in stainless steel metabolism cages in a controlled environment and fed semi-purified diets containing either 2.13 or 12.25 ppm Cu from 30 days of gestation through two weeks of lactation. Feed intake was restricted to 2 kg/day during pregnancy and 4 kg/day in the first two weeks of lactation. Reproductive performance of gilts was measured. Balance studies were conducted at 30, 60 and 100 days of gestation. Mineral levels in the plasma of gilts and piglets, and in colostrum and milk were determined. The low-Cu diet did not affect (p $>$ 0.05) weight changes during pregnancy. The duration of parturition was shorter for low-Cu than for control gilts (3.19h vs 5.71h, p 0.05). Low-Cu gilts had lower plasma Cu in early- and mid-gestation and farrowed piglets with lower plasma Cu and higher plasma Zn concentrations (p 0.05). Plasma Cu and Fe levels of newborn piglets were lower than those of their dams (p 0.05). Low-Cu gilts had lower Cu and higher Zn content in colostrum and also lower Cu in milk than control gilts (p 0.05). Colostrum was richer in Cu and Zn than milk (p 0.05). Higher dry matter digestibility was observed in low-Cu gilts during early gestation (p 0.05). Compared to control gilts, the low-Cu gilts tended to have higher Cu and Zn retention which was achieved by reduction of fecal Cu and Zn excretion. Utilization of minerals appeared to increase as pregnancy progressed.

A programme of study was undertaken to assess the welfare status of multiparous gestating sows housed in dynamic groups in a straw yard and fed by electronic sow feeders (ESF). Comparison of production figures from the Seale-Hayne herd with those nationally confirmed its status as a typical commercial unit. In an initial series of investigations, detailed ethograms were compiled to describe the animals' repertoire of activities and interactions. Lying and straw manipulation were found to be the predominant behaviours and attacks directed towards the head were the most commonly performed type of interaction. Although there was little evidence of aggressive behaviour, most interactions were found to occur in areas where there was an obvious source of competition, namely the feeding and lying areas. A recording scale was devised to assess the level of skin damage arising from aggressive interactions. Whilst data revealed a relationship between parity and the extent of injury, both the frequency and intensity of injury were found to be low for all animals and there was very little evidence of vulva biting, commonly cited as a major criticism of group-housing systems. Animals were observed to rest predominantly in the lying area. There was an association between parity and resting location, with older animals occupying those areas perceived to be more favourable. Recently introduced gilts and sows were observed to integrate gradually with the main group. An argument is put forward for the existence of sub-groups based upon parity within the main group, although it was concluded that it was difficult to prove such a theory. A series of voluntary feed intake (VFI) trials revealed that the animals' feeding motivation was not satisfied by the allowance fed in gestation. Results from a trial when animals were offered a high fibre, low energy diet in comparison with their conventional feed suggested that the animals had a requirement for a certain level of energy and were not motivated simply by a desire for gut-fill. However, a subsequent investigation into the animals feeding behaviour did not reveal any evidence of a frustrated feeding motivation; there was little evidence of non-feeding visits and few animals were recorded in the feed queue throughout the day. It is concluded that sows can be group-housed in a dynamic system on a restricted feed intake without detriment to their welfare or productivity status. A number of factors were found to be critical to the success of such a system including the freedom for animals to behave as individuals, the regular provision of fresh straw and adequate space for newly introduced animals to integrate gradually with the herd.

Tese de Doutoramento em Ciências Veterinárias na especialidade Produção Animal
The biodegradation of plant cell wall (PCW) carbohydrates is performed by microbial enzymes that are generally referred to as CAZymes. In animal nutrition, it is now well established that the monogastric animals produce a limited repertoire of CAZymes and as such cannot use efficiently some dietary ingredients that sometimes display antinutritional properties. The dietary supplementation with exogenous CAZymes improves the nutritive value of diets and increases animal’s performance. In particular, this study demonstrated that 1,3-1,4-β-glucanases and not cellulases improve the nutritive value of β-glucan-containing diets for monogastric animals. In addition, it was revealed that exogenous enzyme supplementation with β-xylanases improved the nutritive value of diets incorporating wheat lots with high viscosity and low endogenous endo-1,4-β-xylanase activity. In contrast, when the wheat lot showed lower viscosity and higher levels of endogenous endo-1,4-β-xylanase activity, broiler response was clearly diminished. Moreover, the data revealed that xylo-oligosaccharides released by xylanases acting on cereal arabinoxylans display a pre-biotic and positive effect in broiler chicks. However, although we observe an exponential accumulation of genomic and metagenomic information, knowledge on CAZYmes with potential to be used in animal nutrition is limited. This work also aimed to develop high-throughput (HTP) methodologies to isolate and characterize potentially important enzymes for animal nutrition. Thus, 1476 recombinant enzymes were selected and produced recombinantly. The data revealed that 79% of recombinant proteins were produced in the soluble form in Escherichia coli. Factors, such as, organism of origin, gene production strategy, fusion with solubility tags, protein molecular weight and amino acids composition of primary sequences may be used to justify and predict levels of solubility. The establishment of a high-throughput pipeline for recombinant enzyme production was used to obtain a library of feruloyl esterases (FAEs) and glucuronoyl esterases (GEs), enzymes which remove the side chains and break crosslinks between hemicellulosic carbohydrates and lignin. Thus 480 putative FAEs and 20 GEs were produced and biochemically characterized. Following gene isolation, 372 FAEs and 11 GEs were produced in a soluble form in E. coli. Activity results showed that 50% of the enzymes produced retained significant levels of activity and stability. The library of innovative FAEs and GEs produced during this project will be used to develop a novel generation of enzymes for animal nutrition, in particular to exploit the release of cellulose and hemicellulose from lignin.
RESUMO - Na natureza, a biodegradação dos hidratos de carbono da parede celular vegetal é realizada por enzimas microbianas, geralmente conhecidas como CAZymes. Os animais monogástricos produzem um reportório limitado de enzimas para degradação destes hidratos de carbono, não conseguindo usar eficientemente alguns ingredientes da dieta, que muitas vezes manifestam propriedades anti nutritivas. Assim, é sabido que a suplementação com CAZymes exógenas melhora o valor nutritivo das dietas e aumenta o desempenho produtivo dos animais. Este trabalho revelou que as enzimas mais apropriadas para suplementar dietas ricas em 1,3-1,4-β-glucanos são as 1,3-1,4-β-glucanases e não as celulases. Além disso, verificou-se que a suplementação com β-xilanases melhorou o valor nutritivo de dietas que continham variedades de trigo com maior viscosidade e menor atividade endógena de endo-1,4-β-xilanase. Em oposição, quando o lote de trigo apresentou menor viscosidade e maiores níveis de atividade endógena de endo-1,4-β-xilanase, a resposta dos animais à adição das enzimas foi menor. Este trabalho mostra, igualmente, que os xilo-oligossacarídeos, resultantes da degradação de arabinoxilanos por xilanases exógenas, possuem uma ação pré-biótica na alimentação de frangos, promovendo a melhoria do desempenho zootécnico. Contudo, apesar de estarem descritas uma grande diversidade CAZymes, poucas são as estudadas com potencial para serem usadas em alimentação animal. Portanto, este trabalho pretendeu, também, desenvolver metodologias para isolar e caracterizar enzimas potencialmente importantes em larga escala. Foram selecionadas, produzidas e expressas na forma recombinante 1476 CAZymes. Os dados revelaram que 79% das proteínas recombinantes foram produzidas na forma solúvel em Escherichia coli. Verificou-se, ainda, que fatores como o organismo de origem, a estratégia de produção, a fusão com marcadores de solubilidade, o peso molecular da proteína e composição de aminoácidos das sequências primárias, parecem justificar os resultados da solubilidade. Estes ensinamentos foram utilizados para produzir enzimas, tais como ferulolil esterases (FAEs) e glucuronil esterases (GEs), que removem as cadeias laterais e quebram as ligações cruzadas entre hidratos de carbono hemicelulósicos e a lenhina. Assim sendo, foram selecionadas 480 FAEs e 20 GEs para produção recombinante e caracterização bioquímica. Cerca de 372 FAEs e 11 GEs foram produzidos em forma solúvel em E. coli e aproximadamente 50% das enzimas produzidas mantiveram níveis significativos de atividade e estabilidade. Com isto, foi possível identificar e produzir um número significativo de FAEs e GEs com potencial para alimentação animal, em especial as que libertam celulose e hemicelulose da lenhina.
N/A

Anthocyanins are very important nutraceuticals not only because they protect plants against biotic and abiotic stresses (Winkel-Shirley, 2002) and they seem to be involved in plant yield (Frascaroli and Landi, 1998), but also because they exert antioxidant abilities able to protect human and animal health (Virgili and Marino, 2008). Maize is able to accumulate anthocyanin in different tissues (Escribano-Bailon et al., 2004; de Pascual-Teresa et al., 2002), so that it can be considered a functional food. On this basis the general aim of this PhD project was to develop maize genotypes with the usual commercial and nutritional value and at the same time able to accumulate anthocyanins in kernels, so to confer the new colored varieties a surplus value compared to the uncolored traditional ones. In maize different allele combinations of the anthocyanin regulatory genes are able to color different tissues, in different extent. From the evaluation of these different genotypes some interesting results came to light: while the r1 gene seemed to be involved in maize yield, the B/Pl genotypes were able to reach the highest anthocyanin amounts in kernels. Therefore they were used to generate the lines characterized in this PhD thesis (popcorn, polenta and sweet corn). To develop uniform individuals, the parameters affecting the anthocyanin final amount in kernels had been studied: the seed weight, the pericarp thickness, the environment and the expression level of the regulatory genes. Among all, a primary role of the epigenetic phenomena emerged; this fact can complicate the breeding work because it force to select the most colored individuals generation by generation, so surely this aspect must be examined more in depth. In the meanwhile a recurrent breeding scheme was used to develop pop corn, polenta and sugary corn colored with anthocyanin: a commercial yellow line was crossed with the colored variety carrying the B/Pl alleles for the anthocyanin biosynthesis. using the Marker Assisted Selection (M.A.S) to help the selection. The anthocyanin final amount in the kernels of the new developed colored lines has been considered as competitive compared to the usual anthocyanin sources, even if the cooking processing affected – but not wiped off- the pigment content and the antioxidant ability. However the anthocyanin presence seemed not to affect the appreciability degree tested on a blinded group of subjects, so that the new color products could be ready for the market. This kind of work and analyses are very interesting in regard the fact that two Near Isogenic Lines (NIL), differing for the synthesis of only one class of metabolites, are under comparison. This fact can simplify the study of the advantage given by the presence of the anthocyanins in foods; moreover these isogenic foods can also be used to analyze the relationship between the presence of the pigments in foods and the human and animal health and consequently to confer a property to a specific single class of molecules, simplifying the analyses and the reading of results.

In the past 20 years, boron has been identified as an essential trace element for animals and humans but also as an increasingly important industrial pollutant. We examined first whether boron influenced survival of the gastrointestinal nematode Heligmosomoides bakeri. Female Balb/c mice were fed deficient (0.1 mug B/g), marginal (2.0 mug B/g) or control (12.0 mug B/g) diets, and infected with third-stage larvae. Although liver boron concentrations did not differ among diet groups, dietary boron deficiency impaired survival of the parasite and modulated a broad range of cytokines and chemokines. On the other hand, infection history altered liver mineral concentrations. Second, we examined whether elevated boron concentrations would exert toxic effects on H. bakeri in vitro. Boron toxicity was evidenced by reduced motility, fecundity, infectivity and survival. Feeding stages and free-living stages were more sensitive than non-feeding stages and parasitic stages respectively in a dose-dependent manner.

O objetivo deste trabalho foi avaliar fenos de valores nutritivos distintos na nutrição de ovinos quanto à capacidade de síntese microbiana e à cinética digestiva, através de ensaios in vitro, in situ e in vivo, baseados em metodologias convencionais e nucleares. Foram utilizados seis ovinos da raça Santa Inês com peso vivo médio de 40±5,7 kg e providos de cânulas no rúmen e no duodeno proximal. Fenos de alfafa (ALF), de braquiária (BRA) e de Tifton-85 (TIF) foram escolhidos devido a seus teores de proteína bruta (PB) (respectivamente, 191, 29 e 75 g.kg-1 MS). Dois delineamentos experimentais foram utilizados: quadrado latino amalgamado (3 tratamentos, 3 períodos e 6 animais) e fatorial completo (3 substratos e 3 inóculos). O primeiro delineamento foi utilizado para os ensaios de consumo voluntário (CVMS), degradabilidade ruminal in situ, parâmetros ruminais, digestibilidade aparente, balanço de nitrogênio, trânsito de digesta e trânsito e síntese de proteína microbiana in vivo. O segundo delineamento foi utilizado para os ensaios in vitro de degradabilidade ruminal, produção de gases e síntese de proteína microbiana. Os fenos apresentaram diferenças (P < 0,05) quanto à sua composição química (matéria seca, matéria orgânica, fibra em detergente neutro, hemicelulose, celulose e PB). O CVMS de ALF foi superior (P < 0,05) aos de BRA e TIF e refletiu a forte relação entre consumo e teor de PB na dieta. As degradabilidades ruminais in situ e in vitro demonstraram a baixa fermentabilidade de BRA, fato que foi comprovado pela técnica in vitro de produção de gases. Não houve diferenças (P > 0,05) entre os valores de pH ruminais dos animais alimentados com ALF, BRA ou TIF, porém a concentração de nitrogênio amoniacal ilustrou bem a importância da proteína dietética para garantir um ambiente ruminal saudável. O tratamento BRA não forneceu proteína suficiente para suprir a quantidade mínima de nitrogênio amoniacal solúvel no rúmen, nem mesmo nas primeiras horas pós prandiais. Os coeficientes de digestibilidade aparente de matéria seca e matéria orgânica foram superiores (P < 0,05) para ALF. A digestibilidade aparente da PB apresentou diferenças (P < 0,05) entre os três tratamentos, sendo que a maior foi observada para ALF (0,694) e a segunda, para TIF (0,500). A digestibilidade aparente da PB de BRA foi praticamente nula (0,001), indicando déficit protéico intenso, o que pôde ser comprovado pelo balanço de nitrogênio. A técnica in vitro de incorporação de radiofósforo para estimativa da síntese microbiana mostrou que houve efeito do tipo de inóculo (P = 0,0089) mas não do período, do substrato ou da interação inóculo*substrato (P > 0,05). A técnica de derivados de purina, por outro lado, conseguiu representar as diferenças na capacidade de síntese microbiana, sendo que a maior produção microbiana foi observada para ALF. A análise geral dos resultados permitiu concluir que: i) o CVMS e a digestibilidade aparente dos fenos foram influenciados pela composição química dos alimentos, pela eficiência microbiana e pelas cinéticas de degradação, fermentação, passagem e digestão; ii) alimentos com baixo teor protéico tiveram efeito prejudicial no aproveitamento de nutrientes por ovinos e na manutenção de um ambiente ruminal saudável; iii) as técnicas in situ e in vitro para estimativa da cinética de degradação foram compatíveis; e iv) a cinética fermentativa (produção de gases) descreveu com maior fidelidade a degradação do alimento devido à ação microbiana.
The objective of this work was to evaluate hays of distinct nutritive values in sheep nutrition regarding to microbial synthesis capacity and digestive kinetics, through in vitro, in situ and in vivo assays, based in conventional and nuclear methodologies. Six Santa Inês sheep (LW = 40±5.7 kg) with rumen and duodenum cannulas were used. Alfalfa (ALF), signalgrass (BRA) and Tifton-85 (TIF) hays were chosen due to their crude protein (CP) content (respectively, 191, 29 and 75 g.kg-1 DM). Two experimental designs were used: Latin square (3 treatments, 3 periods and 6 animals) and complete factorial (3 substrata and 3 inocula). The first one was used for assays of voluntary intake (DMI), in situ rumen degradability, rumen parameters, apparent digestibility, nitrogen balance, digesta transit and in vivo microbial protein transit and synthesis. The second one was used for in vitro assays of rumen degradability, gas production and microbial protein synthesis. Treatments presented differences (P < 0.05) in their chemical composition (DM, OM, NDF, hemicellulose, cellulose and CP). DMI of ALF was superior (P < 0.05) to BRA and TIF DMI and it reflected the strong relationship between intake and CP content in the diet. In situ and in vitro rumen degradabilities showed the poor fermentability of BRA, fact demonstrated by in vitro gas production technique. There were no differences (P > 0.05) between rumen pH values for animals fed with ALF, BRA or TIF, however, ammonia nitrogen concentration illustrated the importance of the dietary protein to guarantee a healthful rumen environment. Treatment BRA did not supply protein enough to supply the minimum amount of rumen soluble ammonia nitrogen. DM and OM apparent digestibility coefficients were superior (P < 0.05) for ALF. CP apparent digestibility presented differences (P < 0.05) between the three treatments, being ALF (0.694) the highest observed followed by TIF (0.500). CP apparent digestibility of BRA was practically null (0.001), indicating intense protein deficit, what it could be proven by nitrogen balance. The in vitro radiophosphorous incorporation for estimating the microbial synthesis showed that there was effect of inoculum (P = 0.0089), but not of period, substratum or inoculum*substratum interaction (P > 0.05). Purine derivatives technique, on the other hand, showed the differences in microbial synthesis capacity, where the greatest microbial production was observed for ALF. The general analysis of the results allowed to conclude that: i) DMI and apparent digestibility of hays were influenced by chemical composition of feeds, by microbial efficiency and by degradation, fermentation, passage and digestion kinetics; ii) feeds with low protein content had negative effect in sheep nutrient availability and in the maintenance of a healthful rumen environment; iii) in situ and in vitro techniques for estimating the degradation kinetics were compatible; and iv) fermentative kinetics (gas production) described with higher fidelity the feed degradation due to microbial activity.

There is evidence from a number of species that body condition or fatness plays a role in the regulation of energy balance, through a direct effect on voluntary food intake (VFI). However, since differences in body condition are frequently confounded with differences in previous nutrition, this study investigated the role of both factors in the control of VFI in sheep. In ewes grazing autumn pastures, there was a negative effect of body condition on VFI, but no independent effect of the previous level of nutrition. However, there was an interaction between the effects of body condition and herbage availability on intake, since VFIs of fat ewes differed with sward height while VFIs of thin ewes did not. The effect of early nutrition on VFI in growing lambs was studied in an experiment where ewes were given either a restricted or adequate level of nutrition in late pregnancy and early lactation. Mean live weight and gut development at weaning were reduced in lambs whose nutrition was restricted during both pregnancy and lactation, but subsequent VFI was not affected. Feeding behaviour was investigated in fat and thin sheep eating a pelleted diet. Thin ewes had higher intakes and spent more time feeding that fat ewes, but the number of meals and rate of ingestion during meals was the same. Both fat and thin ewes increased meal frequency and ingestion rate when food access time was reduced. Differences in VFI were found to persist longer than differences in body condition. Basal plasma insulin concentrations and those measured following an exogenous insulin challenge were both higher in sheep that had remained fat, than in sheep that had previously been thin. This is consistent with the hypothesis that insulin may provide a long-term negative feedback signal to the brain in fat animals, resulting in lower VFIs.

Interactions between manganese (Mn) deficiency and streptozotocin (STZ)-diabetes with respect to tissue antioxidant status were investigated in male, Sprague-Dawley rats. All rats were fed either a Mn-deficient (1 ppm) or a Mn-sufficient (45 ppm) diet for 8 weeks. Diabetes was then induced by tail-vein injection of STZ (60 mg/kg body weight), after which the rats were kept for an additional 4 to 8 weeks. The control groups comprised rats not injected with STZ, which were either Mn-deficient or Mn-sufficient. The Mn-deficient diet decreased the activities of manganese superoxide dismutase (MnSOD) in kidney and heart, and of copper-zinc superoxide dismutase (CuZnSOD) in kidney, in non-diabetic animals. In the diabetic rats, the Mn-deficient diet induced more pronounced decreases in activities of these same enzymes, and also increased liver MnSOD activity. Pancreas weights were significantly lower in Mn-deficient, compared to Mn-sufficient rats. Also, Mn-deficient, diabetic rats were significantly more hyperglycemic in response to a glucose load than Mn-sufficient, suggesting that they may have been more severely diabetic. Surprisingly, plasma and hepatic vitamin E levels increased progressively with the duration of diabetes. Lipid peroxidation, as measured by H₂O₂ -induced production of thiobarbituric acid reactive substances in erythrocytes, plasma lipoperoxides, and renal adipose tissue fluorescence, also increased concomitant with decreased liver and kidney glutathione levels. The effect of vitamin E-deficiency on Mn-deficient, diabetic rats was also investigated. Predictably, vitamin E-deficient rats were almost entirely depleted of plasma and liver vitamin E after 12 weeks on the deficient diets (4 weeks after STZ treatment). Consistent with this, tissue lipid peroxides were elevated compared to vitamin E-sufficient rats. Superimposing vitamin E-deficiency on manganese deficiency failed to add any further deficits in tissue antioxidant status. Higher glycosylated hemoglobin levels were observed in vitamin E-deficient, compared to vitamin E-sufficient, diabetic rats. These findings demonstrate for the first time an interactive effect between manganese deficiency and STZ-diabetes resulting in amplification of tissue antioxidant changes seen with either manganese deficiency or STZ-diabetes alone. This effect of cofactor deprivation in experimental diabetes raises the question of adequacy of the nominally Mn-sufficient diet in insulin-dependent diabetes mellitus.
Land and Food Systems, Faculty of
Graduate

Three experiments were conducted to study the sensitivity of the pH-stat (in vitro) method in the prediction of true digestibility (TD), as measured by amount of base added, of plant proteins, either alone or in the presence of specific additives (nitrogen-free mixture, vitamin mixture and/or mineral mixture) as part of a complete diet of plant proteins that had been subjected to various levels and forms of heating. The in vitro TD values were then compared with TD values obtained in. vivo (Wistar rats). In experiment 1, the effect of temperature (dry-heating at 80, 100, 120, 150, 180 and 240° C or autoclaving at 121° C) and time (30, 60, 120 and 240 minutes) of heat application on in vitro base consumption (BC) was measured in 3 grains (wheat, barley and sorghum) and whole defatted soybeans. The largest increase in BC measured by the pH-stat method was that of soybeans in response to 30 minutes of autoclaving. Dry heating had various effects on the BC by soybeans, depending upon temperature and time of application, but none of the treatments was as beneficial as autoclaving. Mild, dry-heating of grains at 80-120° C improved BC slightly. The improvement was most marked for wheat. Both dry-heating of grain at temperatures above 120° C and autoclaving reduced the BC significantly for all durations. In experiment 2, the effect of inclusion of non-protein dietary components (minerals, vitamins and a nitrogen-free mixture, singly and in combination) on in. vitro BC measured by the pH-stat method of wheat and fat-extracted soybeans (both proteins in the raw and autoclaved forms) was monitored. For the wheat treatments, the inclusion of a mineral mixture significantly (p<0.001>) increased digestibility. This effect was greatest with autoclaved wheat. It was concluded that, in general, the presence of minerals increased the rate of hydrolysis. With raw soybeans, the distinction between treatments was less well-defined. The treatments containing vitamin or nitrogen-free and mineral combination mixtures were digested to a significantly greater extent than the raw soybeans alone. With autoclaved soybeans, additives had no effect. This lack of response to additives may have been due to the rather large amount of base required by the autoclaved soybean protein alone. In experiment 3, a series of rat-feeding trials were conducted in conjunction with in. vitro digestions. Diets were fed to groups of Wistar rats to determine TD, Biological Value (BV), and Net Protein Utilization (NPU) in vivo. Although BV was measured it was not relevant for this work. Concurrently, the same diets were tested for in. vitro TD by the pH-stat method. Specific regression equations were developed for each protein-type tested, after it was determined that a much lower correlation coefficient was obtained when one general equation was utilized. The newly-developed equations followed the format y = a + bx, where y = TD (as a part of one), a = the y-intercept, b = slope of the function and x = ml 0.10N NaOH added during the 10-minute digestion. Regression equations, correlation coefficients (r) and standard errors for each regression (s) between in. vitro and in vivo true digestibility of proteins were as follows; Soybean, soybean (autoclaved), soybean/wheat combinations (n = 6) r = 0.93 TD = 0.7868 + 0.2175x s = 0.018 Sorghum (raw, autoclaved, 90° C, 120° C, 180° C dry-heated, steamed) (n = 6) r = 0.92 TD = 0.4575 + 1.8841x a = 0.058 Alfalfa pellets/hay in combination with either wheat or barley (n = 13) r = 0.91 TD = 0.3446 + 1.0356x s = 0.046Alfalfa hay and barley combinations (n = 5) r = 0.96 TD = 0.2360 + 1.3194x s = 0.048 Grains (19 barleys, 10 triticales, 6 sorghums, and 2 wheats) (n = 37) r = 0.74 TD = 0.7419 + 0.4759x s = 0.044 In general, it can be stated that the pH-stat method is a useful method for screening proteins for the effect of various treatments on digestibility. Damage due to abnormally severe processing conditions (i.e. heating) is readily detected by the pH-stat technique as indicated by a decrease in the amount of base consumed during enzymatic hydrolysis.
Land and Food Systems, Faculty of
Graduate

Objectives were to determine net uptake or release of α-amino N (AAN), ammonia N (NH₃N) and urea N (UN) across portal-drained viscera (PDV), liver, splanchnic (PDV + liver) and mammary tissues of lactating cows fed differently processed sorghum or corn. Cows were fitted with catheters in blood vessels (artery and portal, hepatic and mammary vein), and received in a switchback design TMR containing 40% dry-rolled (DR; 643 g/L or 50 lb/bu) or steam-flaked (SF; 360 g/L or 28 lb/bu) sorghum (Exp. 1), and steam-rolled (SR; 489 g/L or 38 lb/bu) or SF corn (Exp. 2). Neither daily intake of DM and nutrients nor milk yield and efficiency of milk production were altered by feeding processed sorghum or corn. Milk fat yield was lowered (P=.03) by SF vs. DR sorghum; SF vs SR of corn tended to increase (P=.07) concentration but not yield of milk protein. Blood flows in portal (1988 ± 109 L/h) and hepatic vein (2368 ± 215 L/h) were not altered by diets. Steam-flaked vs. DR sorghum tended (P=.18) to increase UN cycling (162 vs. 95 g/d), and reduced (P≤.09) absorption of AAN (223 vs. 269 g/d) and NH3N (257 vs. 318 g/d) by PDV. Flaking vs. rolling of sorghum increased (P≤.07) estimated uptake (83 vs. 67 g/d) and extraction ratio (14.5 vs. 11.1%) of AAN by mammary tissues. Net uptake and release of AAN and NH3N across splanchnic tissues of cows were not altered by corn processing; however, SF vs. SR corn increased (P=.08) UN cycling to PDV by 143% (212 vs. 87 g/d). Steam-flaked vs SR corn increased (P≤.02) estimated uptake (88 vs. 61 g/d) and extraction ratio (14.7 vs. 11.0%) of AAN by mammary tissues. It is concluded that feeding of steam-flaked sorghum or corn compared to dry-rolled sorghum or steam-rolled corn improves N utilization of dairy cows by increasing urea transfer to the gut and uptake of amino acid by the mammary gland.

Master of Agribusiness
Department of Agricultural Economics
Vincent Amanor-Boadu
Cargill Animal Nutrition is a global manufacturer and distributor of animal nutrition products. They operate in the United States through 6 separately managed regions that control a number of facilities throughout the entire United States. Cargill Animal Nutrition Southeast Region manages a network of eleven plants and two warehouses in the southeast part of the United States. The purpose of this thesis is to explain the current supply chain design including the relationships that exists between facilities, analyze the costs associated with the current design and relationships, and assess the feasibility of alternative designs of supply chain strategies available. A brief description of each facility along with production characteristics specific to each facility is given. Due to certain production characteristics, dependent relationships exist between certain plants. These relationships create restrictions to which our supply chain is subject. Other relationships are not as rigid and thus can be manipulated in pursuit of lowering overall supply chain costs. The model resulting from this thesis will facilitate the assessment of the feasibility of these changes. There are many costs associated with the supply chain; however, costs included in this analysis are limited to the costs that could vary when changing suppliers. The price of the product, transportation costs, and certain warehouse fees deemed relevant to this research are applied to the expected annual sales tons to reach a total cost of supply chain considering the assumptions made. The base scenario was defined according to known facts regarding the current design of our supply chain, which included identification of suppliers, supplier prices, transportation costs, and associated handling/warehouse fees, as well as determining the quantity of product that would need to flow throughout our supply chain. Then the total cost associated with the current supply chain design was assessed according to our analytical model. Once the total cost of the base scenario was determined, comparison to alternative scenarios could take place. Changing the relationships between locations of the supply chain results in alternative scenarios to which the analytical model and decision rule developed can be applied to determine feasibility of the alternative supply chain designs. Operating within the confines of the research, the total cost of the current supply chain design was determined to be $15,697,426. That total cost then serves as a base figure which can be used in comparison with the overall cost of alternative scenario #1. Scenario #1 resulted in a total cost of $15,447,597 – an annual savings of $249,828. Scenarios #2 through #4 were evaluated against the total cost of scenario #1. The total cost of scenario #2 is $15,421,364 which results in annual savings of $26,234. Scenario #3 results in a total supply chain cost of $15,347,888 which equates to annual savings of $9,710 in comparison to scenario #1. The final scenario in this study results in a total cost of $15,443,547. The annual savings generated by scenario #4 in comparison to scenario #1 are $4,050. The results indicate that there are alternative configurations of Cargill Animal Nutrition’s Southeast supply chain that can be developed to increase the competitiveness of operations and improve operational excellence through cost savings. These results are used to inform management in the implementation of the new goals that have been established for the organization. Further utilization of the tool developed will result in increased knowledge of the costs associated with supply chain design. This will allow the company to be able to understand the cost of their supply chain so they can benefit from decreased supply chain costs by reacting to changing market factors.

This experiment evaluated rumen protein:energy synchronization in steers fed either gamagrass (Tripsacum dactyloides) or orchardgrass (Dactylis glomerata) hays with or without a soybean hull/corn supplement. A N balance trial was conducted to compare the effects of the supplement and hay on N intake, N digestion, and N metabolism. The supplement consisted of 50:50 corn: soybean hulls mix with 50 g molasses per kg of corn: soybean hulls mixture. The supplement contained 11.3% CP, 34.2% NDF, 22.9% ADF, and 0.87 kg was fed at 0830 and 1600 followed by hay offered in two equal portions. Steers had ad libitum access to water and a trace mineralized salt block throughout the study. Hay compositions were 8.3% CP, 71.8% NDF, and 37.8% ADF for gamagrass and were 11.9% CP, 70.5% NDF, and 36.6% ADF for orchardgrass. Steers were individually fed, blocked into two weight groups, and randomly assigned to either gamagrass or orchardgrass hay (4 steers per hay). Within hays, steers were assigned to receive supplement or no supplement in a crossover design. Ad libitum DM intake for each steer was equal to their intake during the last 8d of the 21-d ad libitum period. Steers were then placed in metabolism crates for an 8-d adjustment followed by a 5-d balance trial. During the balance trial, steers were fed 90% of ad libitum intake. Compared with gamagrass, orchardgrass had similar true IVDMD (64.2 vs 62.2%), similar leaf true IVDMD (58.2 vs 63.2%), and similar stem true IVDMD (46.7 vs 51.7%). Effects were significant at P < 0.10. Compared with gamagrass, orchardgrass had a lower ad libitum DM intake (4.62 vs 5.37 kg/d), higher N intake (96.6 vs 81.1 g/d), similar fecal N (36.1 vs 34.5 g/d), higher N digestibility (62.4 vs 57.4 %), similar N retained (27.2 vs 27.7 g/d), and lower digestible DMI (3.20 vs 3.53 kg/d). Compared with no supplement, supplement increased digestible DM intake (3.70 vs 3.03 kg/d), total DM intake (5.87 vs 5.07 kg/d), N intake (96.9 vs 80.8 g/d), fecal N (39.4 vs 31.1 g/d) and N retained (31.7 vs 23.2 g/d). Supplement (1.74 kg/d) decreased hay ad libitum intake by 0.73 kg/d. Supplement decreased, blood urea N, urine urea N and urine urea N as a percentage of urine N more for orchardgrass than for gamagrass. Supplement tended (P < 0.11) to improve N retained as a percentage of N intake or percentage of N digested more for orchardgrass than for gamagrass hay. Blood urea N was reduced (2.21 vs 0.14 mM)more for steers fed orchardgrass hay than for steers fed gamagrass. We believe that the increase in digestible OM intake is due in part to the presence of soybean hulls in the supplement.

Dairy slurry and poultry litter have increased in popularity as fertilizers in the agriculture industry. However, residual effects of these manures on voluntary intake of forages from subsequent harvests are not well known. The objectives of this two part study were to determine if moisture level of alfalfa silage and the use of dairy slurry as a fertilizer have an effect on intake and digestibility by sheep, and if forage species and the use of poultry litter as a fertilizer have an effect on intake by horses. Eighteen ewes (47.6 ± 5.34 kg) were used in experiment 1 and were allocated randomly to 1 of 6 treatments arranged in a 2 × 3 factorial treatment arrangement. Treatments consisted of high (HM; 46.8%) or low (LM; 39.7%) moisture alfalfa silage at baling after no slurry application (NS), slurry applied to stubble immediately after removal of the previous cutting (S0) or 14 d after the previous cutting (S14). Experiment 2 used 5 mature geldings (480.3 ± 52.89 kg) in a balanced incomplete block design to evaluate preference for bermudagrass (B) or teff (T) hay that was harvested after no litter application (NL), litter applied immediately after the removal of the previous cutting (L0) or 14 d after the previous cutting (L14). Animals were housed individually: sheep were housed in 1.4 × 4.3 m pens and horses were housed in 3.6 × 3.6 m indoor stalls with access to 3.6 × 7.6 m outdoor runs. All animals were offered mineral and had ad libitum access to water. Intake by sheep did not differ (P ≥ 0.13) across treatments. Dry matter and OM digestibility by sheep tended (P < 0.10) to be greater for LM compared with HM. In horses, intake was greater (P < 0.01) for bermudagrass and NL and L0 treatments compared with teff and L14. Therefore, the use of manure as a fertilizer may not affect voluntary intake in sheep, but application time may affect intake in horses.

The interaction between dietary crude protein and amino acid levels in weaner pigs in an antibiotic-free environment with or without Bacillus amyloliquefaciens supplementation Natasha van Niekerk High crude protein (CP) diets cause a myriad of digestive problems in weaner pigs due to incomplete digestion. This is caused by an immature digestive system at weaning. These problems present themselves as increased diarrhoea and reduced growth performance in weaner pigs. Many of the negative consequences could in the past be rectified through the use of antibiotic growth promoters (AGPs). However, AGPs are becoming more closely scrutinised by the general public and government officials and it is therefore imperative that alternative feed additives and dietary strategies are explored so that weaner pig performance is not impaired in the face of AGP bans. The effect of a 3% dietary CP reduction and 10% elevation of lysine, methionine, threonine, tryptophan and valine and/or Bacillus amyloliquefaciens was investigated in weaner pigs of 28 days old. The experiment was performed on 162 pigs with six dietary treatments; comprising of two CP levels (21% or 18% in the pre-starter diets and 18% or 15% in the starter diets), two amino acid levels (recommended amino acid level or elevated by 10%) and with or without the supplementation of a probiotic additive (Bacillus amyloliquefaciens). The total trial period was 42 days, divided into a pre-starter phase and starter phase, both of 21 days each. Growth performance and faecal score was measured for the entire trial period. In addition, after 21 days of the trial, 54 pigs were humanely euthanised to determine the gut health effects of the dietary treatments. Crude protein level resulted in significant effects on body weight (BW), average daily gain (ADG) and gain to feed ratio (G: F) in both the pre-starter and starter phase. The pigs consuming the HP diets had increased (p <0.05) BW at day 7, 14, 21, 28 and 35, and higher ADG (p <0.01) between days 7-14 and 7-21. In addition, high CP diets resulted in increased (p <0.05) G: F in the periods 7-14, 7-21, 21-42 and 7-42. This was due to the negative impact incurred as a result of deficiencies in certain essential AA and the standard ileal digestible (SID) Lys to CP ratio (SID Lys: CP) of 6.9% being exceeded when CP was reduced, and supplemental AA increased. The reduction in CP resulted in improved faecal scores. The supplementation of the probiotic did not result in any significant effects on performance but did exert a positive synergistic effect with the low CP diet on gut health, as observed through improved faecal score. Ileal villi height was significantly increased in high CP diets, possibly indicative of increased nutrient availability in the high CP diets. Crypt depth was also increased in the high CP diets, indicative of increased cell proliferation. There were no significant dietary effects on the pH and ammonia content of caecal digesta, or the presence and enumeration of Salmonella and Escherichia coli (E. coli) in ileal and caecal digesta. Interestingly, the supplementation of the probiotic increased the relative liver weights of the pre-starter pigs. Results of the study suggest that in order for the strategy of reducing CP in weaner pig diets to be successful, no deficiencies in essential or non-essential amino acids should be present. In addition, low CP diets in conjunction with a probiotic can improve faecal scores of weaner pigs, providing an effective solution to replacing AGPs.
Dissertation (MSc)--University of Pretoria, 2020.
Evonik Nutrition & Care GmbH
Animal and Wildlife Sciences
MSc (Agric) Animal Nutrition
Unrestricted

The processing of soya oilcake is important to ensure protein availability and high degradability of the soya proteins. Pig producers in South Africa are concerned about the quality of locally processed soya oilcakes and the effect that it may have on the intestinal health and lifetime production of the pig. The primary aim of this study was to compare the quality of locally processed soya oilcake to soya oilcake imported from Argentina. The trail consisted of two parts. In part one of the trail, eighty-eight samples of soya oilcakes from three different processing plants in South Africa and one from Argentina was analysed for their nutritive value and antinutritive factors. The results from the in vitro analyses were used to conduct the second part of this trail. Thirty-two piglets were divided into four treatment groups, the control group (diet containing no trypsin inhibitors), a low trypsin inhibitor group, a medium trypsin inhibitor group and a high trypsin inhibitor group. A digestibility trail was conducted to determine the effect of antinutritive factors on the digestibility of CP in pigs. The nutrient analyses suggested that the imported soya oilcake is of better quality than the locally produced product. All the results for the imported soya oilcakes were very consistent, with minor variations and had lower trypsin inhibitor activity. The results obtained from this study showed that some of the local soya oilcake processing plants in South Africa produced products of higher quality than others. One of the locally processed soya oilcakes, named soya oilcake 3 in this study, was identified as a good replacement for the imported soya oilcake. Soya oilcake 3 had a CP value of 53.11% which compared well with the imported soya oilcake with a similar CP value of 53.51%. The trypsin inhibitor concentration of the imported soya oilcake was the lowest and the second lowest in soya oilcake 3. Due to the high variance found in the results obtained from the in vivo digestibility study, it is not possible to make a conclusion on the effect of feeding lower quality soya oilcakes to weaner pigs. Further research is needed on the effect of trypsin inhibitor on gut health and digestibility of crude protein in weaner pigs.
Dissertation (MSc)--University of Pretoria, 2019.
Topigs, Evonik Africa (Pty) Ltd, Addesio
Animal and Wildlife Sciences
MSc
Unrestricted

The utilization of Pennisetum purpureum (Napier grass var Bana) based diets and the lactation performance of dairy cows in coastal lowland Kenya was studied in a series of five experiments. In experiments 1 and 2, the effects of 300g/day additional crude protein from locally available fishmeal, copra cake and Leucaena were compared using Jersey cows fed ad libitum Napier grass. Experiment 1 carried out in early lactation, showed that supplements (fishmeal or copra cake) could increase dry matter DM intake, reduce live-weight loss and increase (P< 0.05) milk output (7.8 v 6.4kg/day) with no differences between the supplements. Experiment 2 was carried out in mid lactation. Cows fed supplements (a mixture of copra cake/maize bran or Leucaena) consumed more (P< 0.01) DM with no effect on Napier grass intake and produced more (P< 0.05) milk no difference between supplements. No significant changes in live weight were observed. Ayrshire/Brown Swiss x Sahiwal cattle were used in experiments 3 to 5. In experiment 3, the effects of Napier grassharvesting height (1.0 v 1.5m) and level of Leucaena (0,4 and 8kgFW) were evaluated in early lactation. Feeding Napier grass harvested at 1.0m compared with 1.5m increased (P&60 0.01) Napier grass intake (9.3 v 6.8kg/day), reduced live-weight losses (0.16 v 0.49kg/day) and increased milk yield (8.6 v 6.9kg/day). Feeding Leucaena (0, 4 and 8kgFW; DM280g/kg) significantly (P< 0.01) increased total DM intake (7.8, 9.3 and 10.4kg/day), reduced live-weight loss (0.53, 0.23 and 0.17kg/day) and increased milk yield (7.3, 7.7 and 8.3kg/day).

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
Aiming to evaluate feeding programs (FP) with different levels of calcium (Ca) and available phosphorus (aP) on rations containing phytase for piglets, one hundred sixty- eight barrows and females weighing 8.11 ± 0.61 kg were weaned at 28 days and blocked according to initial body weight. Inside each block, piglets were randomly distributed to one of seven feeding programs with eight replicates and three piglets per experimental unit.The treatments consisted of control FPwithout phytase and six with decreasing levels(%) of aP and calcium (Ca) with the addition ofphytase(2,000 FTU/kg), as follows: FP1: (aP: 0.435-0.385-0.315; Ca: 0.850-0.825-0.768); FP2: (aP: 0.370-0.320-0.250; Ca:0.850-0.825-0.768); FP3: (aP: 0.305-0.255-0.185; Ca: 0.850- 0.825-0.768); FP4: (aP: 0.435-0.385-0.315; Ca:0.690-0.665-0.608); FP5: (aP: 0.370- 0.320-0.250; Ca: 0.690-0.665-0.608); FP6: (aP: 0.305-0.255-0.185; Ca: 0.690-0.665- 0.608). The FP3, FP5 and FP6 resulted in higher average daily gain and feed intake in comparison to control,from 28 to 35 days. Only FP6 resulted in higher average daily gain in comparison to control, from 28 to 49 days. The FP6 resulted in lower verage daily gain when compared to FP1, from 28 to 63 days.The FP1, FP2, FP4 and FP5provided greater bone mineralization when compared to control. The FP1resulted in greater bone mineralization than FP3, FP5 and FP6. The FP3 resulted in less bone mineralization than FP1, FP2 and FP4. Bone Ca was lower on FP5 when compared to FP1. With the exception of the FP3, phosphorus (P) of the bone was higher on all treatments when compared to control, however, the FP3 treatment resulted in less bone P than FP1. The FP4, FP5 and FP6 resulted in lower bone Ca:P ratio when compared to control. The serum Pconcentrations were lower in FP3 and FP6 in comparison to control. Considering only treatments containing exogenousphytase, the FP3 resulted in lower serum P than FP1, FP4, FP5; and FP6 resulted in lower serum P in comparison to FP5 as well. In conclusion, the FP6 results in satisfactory performance of pigs from 28 to 63 days of agealthough providing lower growth rate when compared to FP5.
Objetivando-se avaliar planos nutricionais comdiferntesníveis de cálcio (Ca) e fósforo disponível (Pd) em rações contendo fitase, 168 leitões, machos castrados e fêmeas, com peso corporal inicial de 8,11±0,61kg foramdesmamados aos 28 dias de idade e distribuídos em delineamento em blocos ao acaso, conforme o peso corporal, em sete tratamentos, com oito repetições e três animais por unidade experimental. Os tratamentos foram planos nutricionais (PN), sendo um controle sem fitase e os demais com níveis (%) decrescentes de Pd e Ca com 2.000 FTU de fitase, conforme segue: PN1: (Pd:0,435-0,385-0,315; Ca: 0,850-0,825-0,768); PN2: (Pd:0,370-0,320-0,250; Ca:0,850-0,825-0,768); PN3: (Pd: 0,305-0,255-0,185; Ca: 0,850-0,825-0,768); PN4: (Pd: 0,435-0,385-0,315; Ca:0,690-0,665-0,608); PN5: (Pd: 0,370-0,320-0,250; Ca:0,690-0,665-0,608); PN6: (Pd: 0,305-0,255-0,185; Ca: 0,690-0,665-0,608). O ganho de peso e o consumo de ração diários dos 28 aos 35 dias foram maiores para o PN3, PN5 e PN6 em comparação ao plano controle. Dos 28 aos 49 dias, o ganho de peso diário proporcionado pelo PN6 foi maior em comparação ao controle. O ganho de peso diário foi menor no PN6 em comparação ao PN1, dos 28 aos 63 dias. Os tratamentos PN1, PN2, PN4, PN5 proporcionaram maior mineralização óssea comparados ao controle. O PN1 resultou em maior mineralização óssea que o PN3, PN5 e PN6. OPN3 proporcionou menor mineralização óssea que os PN1, PN2 e PN4. O PN5 resultou em menor Ca ósseo comparado ao PN1. Com exceção do PN3, todos os tratamentos resultaram em P ósseo maior em relação ao controle, mas o PN3 resultou em P ósseo menor que o PN1. O PN4, PN5 e PN6 resultaram em menor relação cálcio:fósforo ósseo em relação ao controle. O P sérico foi menor no PN3 e PN6 em relação ao tratamento controle. Dentre os tratamentos contendo fitase, o PN3 resultou em menor P sérico que o PN1, PN4, e PN5; e o PN6 em menor P sérico que o PN5. Conclui-se que oPN6, correspondente a 0,305-0,255-0,185 de Pd, 0,690-0,665-0,608 de Cae2000 FTU/kgde fitase, apesar de proporcionar menor taxa de crescimento em relação ao PN5, resulta em desempenho satisfatório de leitões dos 28 aos 63 dias de idade.

The overall objective of this thesis was to investigate differences between the FFA and TG forms of CLA regarding incorporation in liver and biological musculoskeletal responses; if assessment of PTH is affected by gender, fasting and the type of PTH assay used; if CLA status, as measured by red blood cell CLA content, in men is positively related to body composition and bone mass; if CLA supplementation in healthy men reduces PTH concentration; and if CLA can prevent decreases in bone and muscle mass typically observed in advanced aging. Methods: Study 1: Sprague-Dawley rats were randomized at weaning to receive a control AIN-93 diet or the same diet supplemented with 0.5% c9, t11 CLA + 0.5% t10, c12 CLA in FFA or TG form. Liver fatty acid profiles were assessed using gas chromatography. Biomarkers of bone metabolism were measured along with bone density and body composition using dual-energy x-ray absorptiometry (DXA) after 4, 8, 16 wk. Study 2: Sprague-Dawley rats were randomized at weaning to receive a control AIN-93 diet or the same diet supplemented with 0.5% c9, t11 CLA + 0.5% t10, c12 CLA in FFA for 16 wk. At wk 16, a blood sample was collected in both a fed state and a non-fed state. PTH was assessed using both a second and third generation PTH assays. Study 3: Healthy men 19-53 y (n=31) were randomized in a double-blind, placebo controlled clinical dose-response trial to receive either: 1.5 g/d or 3.0 g/d of c9, t11 CLA (4:1 c9, t11 to t10, c12 isomer ratio) or placebo (olive oil 3 g/d) for 16 wk. DXA was performed to assess body composition at baseline and end of study and blood samples were obtained monthly to evaluate changes in PTH concentration, 25-hydroxy vitamin D (25(OH)D), iCa, phosphate and lipid profile. Study 4: As an advanced aging model, pigmented guinea pigs (n=40) were block randomized by weight at 70 wk of age to 4 groups: 1) SHAM+Control diet, 2) SHAM+ CLA diet (1.0% 4:1 c9, t11 to t10, c12 isomer ratio), 3) Orchidectomy (ORX)+Control diet, 4) ORX+CLA diet. DXA scans for bone density and body composition in addition to blood samples to measure testosterone, estrogen, interleukin-6 (IL-6), were performed at baseline and wk 16. At 16 wk, iCa and 25(OH)D were assessed as well as, bone microarchitecture using micro computed tomography, bone strength and acute protein fractional synthesis rate in skeletal muscle using a flooding dose of 40 mol% of L-[ring-2H5]-phenylalanine (1.5 mmol/kg ip). Results: Study 1: There were no differences among groups for growth, bone biomarkers or mass nor mineral balance. Liver enrichment of c9, t11 CLA in FFA form was greater than TG form and AIN-93. Study 2: Females had a lower iCa compared to males. In males and females, there was no difference between fed and non-fed groups when PTH was assessed using the INT PTH assay. However, in females only, PTH measured using the BIO PTH was significantly lower in the fed group versus the non-fed. Study 3: Men with red blood cell (RBC) c9, t11 CLA status above the median had higher whole body bone mineral density (BMD) and whole body lean mass % (WBL), whereas body mass index (BMI) and whole body fat mass % (WBF) were lower. In regression analysis, RBC c9, t11 CLA status accounted for a significant proportion (r2=0.10) of the variation in whole body BMD (P=0.03). There were no time or treatment differences among any bone or biomarkers of bone metabolism including PTH. Study 4: CLA prevented an increase in Tb.Sp and a decrease in vBMD in metaphyseal regions of ORX compared to SHAM CTRL. CLA also decreased porosity in ORX compared to SHAM. ORX decreased free testosterone whereas interleukin-6 increased. CLA prevented ORX-induced loss of metaphyseal vBMD and bone volume as well as enhanced diaphyseal porosity. Also, no differences in quadriceps mixed muscle sarcoplasmic and myofibrillar protein fractional synthesis rate were detected. Significance: Overall, small benefits of CLA on the musculoskeletal system were observed.
L'objectif de cette thèse est d'étudier les réponses biologiques musculo-squelettiques de l'acide linoléique conjugué (ALC). Méthodologie: Étude 1: Des rats Sprague-Dawley ont été randomisés pour recevoir le régime de contrôle AIN-93 ou le même régime supplémenté avec 0,5% c9, t11 + 0,5% t10, c12 d'ALC en forme d'AGL ou de TG. Les profils d'acides gras du foie ont été évalués pour l'incorporation de l'ALC dans les tissus. Les biomarqueurs osseux ainsi que la densité osseuse et la composition corporelle ont été mesurés après 4, 8, 16 semaines. Étude 2: Des rats Sprague-Dawley ont été randomisés au sevrage pour recevoir le régime de contrôle AIN-93 ou le même régime supplémenté avec 0,5% c9, t11 + 0,5% t10, c12 d'ALC en AGL pendant 16 semaines. Du sang a été recueilli à la fois dans un état nourri et à jeun. La PTH a été évaluée à l'aide de test de la PTH de deuxième et de troisième génération. Étude 3: Des hommes âgés de 19 à 53 ans (n = 31) ont été randomisés en double aveugle, lors d'un essai clinique contrôlé pour recevoir: 1,5 g / j ou 3,0 g / j de c9, t11 (4:1 c9, t11 à t10, c12 rapport d'isoforme) ou un placebo (huile d'olive 3 g / j) pendant 16 semaines. L'absorptiométrie biphotonique à rayons X (DXA) a été réalisée pour évaluer la composition corporelle. Des échantillons de sang ont été obtenus mensuellement pour évaluer les changements dans la concentration de la PTH, la 25-hydroxy-vitamine D (25(OH)D), l'iCa, le phosphate et le profil lipidique. Étude 4: En tant que modèle de vieillissement avancé, des cochons d'inde pigmentés (n = 40) on été randomizés à 70 semaines d'âge à 4 groupes: 1) chirurgie fictive (SHAM) + Régime de contrôle (CTRL), 2) SHAM + régime d'ALC (ALC) (1,0% 4:1 c9, t11 à t10, c12 rapport d'isoforme), 3) orchidectomie (ORX) + CTRL, 4) ORX +ALC. L'analyse de la densité osseuse et la composition corporelle (par DXA) ainsi que des échantillons sanguins recueillis pour mesurer la testostérone, l'estrogène, l'interleukin-6 (IL-6), ont été. À 16 semaines, l'iCa et la 25(OH)D ont été évaluées ainsi que, la microarchitecture osseuse utilisant la microtomodensitométrie, la force des os ainsi que le taux de synthèse protéique fractionnaire dans les muscles squelettiques en utilisant une dose d'inondation de 40% en moles de L-[ring-2H5]-phénylalanine (1,5 mmol / kg ip). Résultats: Étude 1: Il n'existe aucune différence entre les groupes pour les biomarqueurs et la masse osseuse, ni l'équilibre minéral. L'enrichissement du foie en c9, t11 sous forme AGL était plus grand que sous forme de TG et AIN-93. Étude 2. Chez les mâles et les femelles, il n'y avait pas de différence entre les rats nourris et à jeun lorsque la PTH était évaluée en utilisant le test PTH INT. Cependant, chez les femelles seulement, la PTH mesurée à l'aide de la PTH Bioactive, était significativement plus faible dans le groupe nourri par rapport au groupe à jeun. Étude 3: Les hommes avec un statut d'ALC c9, t11 dans les globules rouges au dessus de la médiane avait une densité minérale osseuse (DMO) du corps et un pourcentage de masse maigre du corps plus élevé, alors que l'indice de masse corporelle (IMC) et le pourcentage de masse grasse corporelle étaient plus bas. Dans l'analyse de régression, le statut d'ALC c9, t11 dans les globules rouges représentait une proportion significative (r2 = 0,10) de la variation de la DMO du corps entier (P = 0,03). Il n'y avait pas de différence temporel et de traitement pour n'importe quel autre mesure d'os ou de biomarqueurs du métabolisme osseux, y compris la PTH. Étude 4: L'ALC a empêché la perte de la densité osseuse et du volume osseux métaphysaire ainsi que l'augmentation de la porosité diaphysaires observés après l'orchidectomie. Également, aucunes différences dans les taux de synthèse fractionnaire des protéines myofibrillaires et sarcoplasmiques n'ont été détectées. Signification: Dans l'ensemble, des petits avantages de l'ALC sur la perte d'os et de muscles ont été observés.

O objetivo desta pesquisa foi estudar a composição químico-bromatológica sobre a variedade de cana-de-açúcar IAC86-2480 submetida a três métodos de colheita. Os tratamentos corresponderam a três métodos de colheita: colheita manual (MAN), colheita mecanizada (MEC) e colheita mecanizada seguido de rebaixamento manual (MEC+MAN). O tratamento relativo ao corte manual foi efetuado na região do colo da planta, rente ao solo, com uso de podão.No caso do corte mecanizado, foi utilizada uma colhedora de forragem regulada para altura de corte de 20 cm. O terceiro tratamento foi aquele em que as plantas foram submetidas ao procedimento de corte mecanizado, e na seqüência, a porção remanescente do colmo (toco) foi cortada rente ao solo com o uso de podão. A área experimental (0,34 ha) foi constituída por seis blocos, com 3 parcelas cada. As parcelas eram formadas por 8 linhas de plantio com 15 m de comprimento em espaçamento entrelinhas de 1,3 m. Os perfilhos eram então separados em 3 frações: colmo, folha e planta inteira. Para a determinação da composição químico-bromatológica (PB, FDN, FDA, DVIVMS e MM) utilizou-se o método de espectroscopia de reflectância de infravermelho proximal (NIRS). O Brix foi determinado em refratômetro digital e a Pol a partir da leitura sacarimétrica do caldo. O Brix, a Pol, o teor de MS, PB, MM, FDN, FDA, DVIVMS, e as relações FDN/Pol e FDN/Brix foram similares (P>0,05) entre os tratamentos. O Brix e a Pol apresentaram comportamento semelhante, revelando os maiores valores na fração colmo, onde também foram encontradas as menores relações FDN/Brix e FDN/Pol. O teor de MM das 3 frações estudadas apresentou oscilações durante o ciclo da cultura, com o maior valor observado na planta inteira aos 90 DAC (8,34%). O teor de PB revelou declínio ao longo do ciclo da cultura, com efeito menos pronunciado observado na fração folha. Do início das avaliações aos 90 DAC, houve decréscimo no teor de MS, atingindo seu menor valor nesta data (16,4%). A partir de então, a cultura apresentou aumento no teor de MS, atingindo 32,3% aos 360 DAC planta inteira. O teor de FDN apresentou queda de 34,8 unidades percentuais, do maior valor (79,7%) para o menor valor encontrado (44,9%) na planta inteira. Dos 90 aos 360 DAC, a DVIVMS aumentou 24,5 unidades percentuais, com média de 2,7 unidades percentuais/mês, atingindo então 66,2% de DVIVMS aos 360 DAC na planta inteira. O método de colheita imposto à variedade de cana-de-açúcar IAC86-2480 não influenciou a composição químico-bromatológica e a planta atingiu valor nutritivo elevado a partir de 270 DAC. O Brix do colmo revelou-se como estimador adequado das relações FDN/Pol e FDN/Brix da planta inteira, que mostraram-se satisfatórias como critério de avaliação nutricional da variedade IAC86- 2480.
The aim of this research was to study the chemical composition of a sugarcane variety (IAC86-2480) under three harvesting methods: manual harvesting (MAN), mechanical harvesting (MEC) and mechanical harvesting followed by manual (MEC + MAN). In manual harvesting (MAN) plants were harvested to ground level, using a cutter. In the case of mechanical harvest, the harvester (adjusted for a cutting height of 20 cm) was pulled by a tractor. For mechanical harvesting followed by manual (MEC+MAN) the same procedures for MEC were followed, however, after cutting, the remaining stalks were cut to ground level with a cutter. The experimental units (0.34 ha) was composed of six blocks, with 3 plots each. The plots were formed by 8 rows with 15 m length spaced by 1.3 m. The tillers were then separated into 3 fractions: stem, leaf and whole plant. To determine the chemical composition (CP, NDF, ADF, IVDDM and Ash) dried samples were scanned through the near infrared reflectance spectroscopy technique (NIRS). The Brix was determined by digital light refractometer and the Pol was determined based on the predicted sacarose from the plant juice. The Brix, the Pol, the content of DM, CP, Ash, NDF, ADF, IVDDM, and the relationships NDF/Pol and NDF/Brix were similar (P>0.05) across all treatments. The Brix and Pol showed similar trends, with the highest value observed in the stem fraction, where the lowest NDF/Pol and NDF/Brix ratios were also observed. The Ash content, of the 3 fractions studied, showed a range of altered values during the crop cycle, reaching the maximum value (8.34%) at 90 DAH (days after harvesting). The mean content of CP declined across the maturity stages studied, with less pronounced effect observed in the leaf fraction. From the beginning of the assessments to the 90 DAH, there was a decrease in the DM content, reaching its lowest (16.4%). Further, the crop tended to increase the DM content, reaching 32.3% for the whole plant at 360 DAH. The content of NDF showed a decrease of 34.8 percentage units, from the highest value (79.7%) to the lowest value found (44.9%) in the whole plant. From d-90 to d-360 DAH, the IVDDM increased 24.5 percentage units, with an average of 2.7 percentage units per month, reaching 66.2% of IVDDM at 360 DAH, in the whole plant. The method of harvesting applied to the variety of sugarcane IAC86-2480 did not affect its chemical composition and the whole plant reached its high standard of nutritive value after 270 DAH. The Brix from the stem was a appropriate predictor of the NDF/Brix and NDF/Pol from the whole plant, which in turn, became reliable criteria for nutritional analysis from the variety IAC86-2480.

Bibliography: leaves 226-261. Investigates nitrogen utilization in some species of rumen bacteria with the object of understanding the role of ammonia versus exogenous amino acids in relation to microbial growth.

Gas chromatography mass spectrometry (GCMS) and inductively coupled plasma mass spectrometry (ICPMS) were evaluated for the measurement of selenium (Se) and Se stable isotope ratios. GCMS and ICPMS were found to be accurate for quantitative Se analysis in biological matrices by isotope dilution using Se-78 and Se-76 as internal standards, respectively. A higher precision was obtained for ICPMS than GCMS enabling a smaller quantity of the tracer to be administered to subjects in labelling experiments. The isotopes of choice for metabolic tracers were Se-76 when sample analysis was by GCMS and Se-77 and Se-82 when analysis was by ICPMS. The influence of copper (Cu) on endogenous fecal Se excretion and true absorption of Se in nonlactating Holstein cows was examined by the use of Se stable isotopes as tracers. The method involved the application of conventional balance techniques in conjunction with isotopic enrichment of the body Se pools. Selenium in several tissues following oral and intravenous routes of isotope administration were evaluated as the precursors of endogenous fecal Se. Two cows fed a Se deficient diet (0.035 mg kg⁻¹) were administered 4 mg Se-76 orally, daily, for 5 d. After a 10-d equilibration period total collection of feces was made daily for two 5-d periods. The animals were then sacrificed and samples obtained from all major tissues and fluids. Se-7 6 enrichment (tracer/tracee mass percent, TTMP) in tissues was variable (< 0.56 - 13.4). However, enrichment was similar (9.8 - 12.9) in the tissues considered as potential contributors to endogenous fecal Se (serum, epithelium of the stomach, liver, bile, pancreas, small intestine and colon). Enrichment in serum and liver was used to calculate endogenous fecal Se. Apparent absorption of Se in the two cows was negative (-37 and -147 µg d⁻¹). Correction of apparent absorption for the fecal Se of endogenous origin gave a true Se absorption (% of intake) of 10 and 16%. The percentage of total fecal Se of endogenous origin was 23 and 36%. In two trials, 5 or 6 cows were assigned to one of two Cu-supplemented treatment diets: 0 mg kg⁻¹ or 17 mg kg⁻¹. The basal diet contained 0.19 mg Se kg⁻¹ and 13 mg Cu kg⁻¹. To each cow ~4.6 mg Se-77 and ~1.3 mg Se-82 were administered by oral and intravenous routes, respectively. After a 14-d equilibration period, total collection of feces and urine were made daily for two 5-d periods. Serum was collected on the first, third and fifth days of each period. Liver biopsies were taken 2 d following the completion of the balance periods. The estimates of endogenous fecal Se ( d⁻¹) from enrichment in the serum (256) and liver (235) following oral administration of the tracer and from enrichment in serum (241) following intravenous administration were not significantly different (P>0.05) but were higher than the estimate from the enrichment in liver (197) (P<0.05). No significant differences (P>0.05) were present when true absorption ( µg d⁻¹) was determined from enrichment in serum (290) or liver (268) following oral administration or from enrichment in serum (274) or liver (230) following intravenous administration. It was concluded the analysis of serum or liver with oral administration or the analysis of serum with intravenous administration of the tracer would provide reliable methods for estimation of endogenous fecal Se and true absorption. There was no effect of Cu on endogenous fecal Se excretion or true absorption of Se. Apparent and true absorption were 3.2 and 11%, respectively. Approximately 90% of the total Se excreted was in the feces, of which, 9.7% was of endogenous origin. The use of Se stable isotopes as metabolic tracers in dairy cattle provided a safe alternative to the use of radioactive tracers and enabled experiments requiring multi-isotopic enrichment to be performed.
Land and Food Systems, Faculty of
Graduate