Academic literature on the topic 'Pelleted feed – Evaluation'

This paper evaluates the eff ects of two diff erent feeds on production results and economic performance in the rainbow trout (Oncorhynchus mykiss) farming. The first group (O-1) was fed with a standard complete pelleted feed, and the second group (O-2) was fed with combined feed consisting of 75 % pellets and 25 % of sardines. Better results were obtained with the O-2 group, while the O-1 group achieved results characteristic for local farming conditions and feed quality. Experimental group O-2 had signifi cantly higher (p<0,01) growth rate when compared to group O-1. Considering current feed and fi nal product (fi sh) prices in the market, better results in terms of cost-eff ectiveness were obtained (E>0,00) in O-2 group of trout fed with the combined meal.

The feed additives flavomycin, a glycolipid antibiotic, and tetronasin, an ionophore, were evaluated for their ability to improve wool growth and liveweight gains in Merino sheep. Each was included in 2 diets: one was a pelleted mixture of (g/kg) lucerne (590), lupins (250) and barley (1 50); the other diet was wheaten chaff. Flavomycin was included in each diet at 10 and 20 mg/kg feed; tetronasin at 5 and 10 mg/kg feed. During an 8-week experimental period, the diets were fed ad libitum to weaner Merino wethers, with 15 sheep receiving each treatment diet at each level of additive inclusion, and 30 sheep receiving each diet without additives. Liveweight changes, feed intake and wool growth were measured over 2 consecutive 4-week periods, and rumen fluid samples were taken from all sheep after 6 weeks. Feed intake, liveweight gain and wool growth rate were all higher for animals eating the pelleted diets compared with those eating chaff. Rumen volatile fatty acids (VFA) and ammonia (NH3) concentrations were also higher with the pelleted diet. On the pelleted diet, flavomycin and tetronasin inclusion significantly increased liveweight gains during the second 4-week period (296, 277, 231 g/sheep.day for flavomycin, tetronasin and controls respectively, P<0.001), but neither additive had any significant effect on feed intake. The amount of clean wool grown during both measurement periods was greater for animals receiving flavomycin or tetronasin with the pelleted diet compared with control animals. Neither additive had any significant effect on liveweight gains or wool growth of sheep eating chaff. Fibre diameter (FD) was measured on wool clipped in the second period, and was not significantly altered by either additive: mean FDs for animal receiving pellets were 25.1 �m, compared with 18.5 �m for animals receiving chaff. Total rumen VFA concentrations were lower with flavomycin or tetronasin treatments on both diets, and ammonia concentrations were lower with both additives on the pelleted diet and with tetronasin on the chaff diet. It is concluded that both flavomycin and tetronasin were able to increase liveweight gains and wool growth in rapidly growing sheep eating a high-protein diet, but had little or no consistent effects with animals eating a lower quality, low-protein diet.

Intensively fed ruminants receive highly fermentable diets to maximise production of meat or milk. However, highly fermentable diets increase the risk of acidosis, which can result in serious health and productive consequences. Accurate evaluation of feed fermentability in both rate and extent is therefore important in controlling acidosis. Differences in (rate of) fermentation between original raw materials are fairly well established and used in current feed evaluation systems (Van Laar et al., 2004). However, the effects of technological treatments, like grinding and especially pelleting of a feed on fermentability are less well explored. In this experiment the nylon bag method was used to analyse fermentability characteristics of a feed that was ground and pelleted in different ways. Additionally the effect on fermentability of pre-soaking the pellets prior to nylon bag incubation was investigated.

Whole canola blended with whole peas (1:1; WCP) or canola meal (3:1; WCC) provide complementary high energy-protein supplements for poultry feeding. Both WPC and WCC blends were fed with or without processing (steam-pelleting or expansion) to broiler chicks in a 14-d feeding trial. Pelleted WCP supported higher body weight gain and feed efficiency than the untreated blend (P < 0.05). Body weight gain and feed efficiency obtained with chicks fed pelleted WCP or WCC were similar to those obtained for the expanded blends (P > 0.05), with notable exception of the expanded WCC which had a lower feeding value. With the pelleted or expanded blends, protein digestibility, N-retention, fat digestibility, and AMEN were comparable or improved over the unprocessed blends, again with the exception of the expanded WCC. The processed blends had higher gelatinized starch, and lower protein solubility and myrosinase activity index. Protein solubility was very low for the expanded WCC, which is indicative of excessive heat damage. Although the expanded blends had lower glucosinolate content, this did not result in improved growth performance over the pelleted blends. It was concluded that the nutritional value of pelleted blends were at least equivalent to that of the expanded WCP and WCC for broiler chicks. Key words: Canola, peas, broiler chicks, expansion, pelleting

Three feed additives were studied for their potential to improve wool growth in sheep fed 2 diets; oaten chaff, or a pelleted mixture (g/kg) of lucerne (590), lupins (250), barley (1 50) and a mineral and vitamin mix (10). Additives were included with each diet as follows (mg/kg feed): avoparcin 25,50,75; flavomycin 5, 15, 30; lasalocid 30, 50, 70. Diets were fed at maintenance to mature Merino wethers for 9 weeks, and measurements were made of wool growth and rumen fermentation characteristics. Animals fed the pelleted diet grew more wool than those fed the chaff diet (6.3 compared with 5.1 g/m2.day, P<0.001), but none of the additives resulted in any significant differences in wool growth compared with the controls. The additives avoparcin and lasalocid increased the ratio of the volatile fatty acids propionate:acetate in animals eating both of the diets (P< 0.001), but flavomycin had no significant effect. Rumen ammonia concentration was increased with avoparcin on both diets (P< 0.001) and with lasalocid and flavomycin on the pelleted diet ( P < 0.05). None of the additives tested significantly influenced liveweight change in comparison with the control groups.

Raw meadowfoam meal (MFM) was fed as part of a pelleted diet to growing beef steers at dietary levels of 0, 12.5 and 25%, with 14 animals per treatment. Over the test period of 84 d, there were no differences in growth rate, suggesting that raw MFM is an acceptable feed ingredient for growing beef cattle. Key words: Cattle, meadowfoam, Limnanthes alba

The objective of this study was to evaluate the effect of different feed management on the quality of effluent water generated in Nile tilapia (Oreochromis niloticus) culture ponds. Feed was supplied as follows: natural food, and pelleted, extruded or minced ration. The study was conducted during 19 weeks in 12 continuous water exchange ponds of 300 m² each, with a population of male Nile tilapia juveniles, in a density equal to 1.7 fish m-2. Feeds contained 30% crude protein, 3,000 kcal digestible energy, and were supplied twice a day. Natural food consisted of chicken manure. Temperature, dissolved oxygen, pH, total phosphorus, total nitrogen, chlorophyll a and suspended solids were monitored weekly in the supplying and effluent water. Water residence time was also determined for the ponds. In general, effluent water quality decreased in all treatments.

Abstract Essential oils (EO) are defined as plant-derived natural bioactive compounds, which can have positive effects on animal growth and health due to their antimicrobial and antioxidative properties. However, EO are volatile, can evaporate quickly, and be rapidly absorbed in the upper gastrointestinal tract. Also, due to their labile nature, the stability of EO during feed processing is often questionable, leading to variations in the final concentration in feed. Encapsulation has become one of the most popular methods of stabilizing EO during feed processing, storage, and delivery into the lower gut. The objectives of the present study were to 1) evaluate the stability of thymol microencapsulated in combination with organic acids in commercially available lipid matrix microparticles during the feed pelleting process and storage; 2) validate and demonstrate the slow release of thymol from the lipid matrix microparticles in a simulated pig gastric fluid (SGF) and a simulated pig intestinal fluid (SIF); and 3) evaluate in vivo release of thymol from the lipid matrix microparticles along the pig gut. The results showed that thymol concentration was not significantly different in the mash and pelleted feeds (P &gt; 0.05). In the in vitro study, 26.04% thymol was released in SGF, and the rest of the thymol was progressively released in SIF until completion, which was achieved by 24 h. The in vivo study showed that 15.5% of thymol was released in the stomach, and 41.85% of thymol was delivered in the mid-jejunum section. Only 2.21% of thymol was recovered in feces. In conclusion, the lipid matrix microparticles were able to maintain the stability of thymol during a feed pelleting process and storage and allow a slow and progressive intestinal release of thymol in weaned pigs.

Twenty reindeer calves (age 10 months) were included in the study. They were all fed one of two different pelleted feed mixtures ad libitum for two months before slaughter. Ten calves were fed a control diet of conventional pellets (CPD) (Renfor Bas, Lantmännen, Holmsund, Sweden) and ten calves received pellets enriched with linseed cake (LPD). The reindeer were slaughtered according to standard procedure at Arvidsjaur Renslakt AB, a reindeer slaughter plant in Arvidsjaur, Sweden. At 1 day post mortem, both longissimus dorsi (LD) muscles from each carcass were excised. The left LD was used for sensory evaluation and the right LD for colour and water-holding capacity measurements. The right LD was cut in 4 pieces that were randomly allocated to storage times of 1 day, 1, 2, or 3 weeks at + 4 °C. Samples allocated for storage were vacuum packaged. Evaluation of meat colour was carried out after each of the four storage times while drip loss/purge was registered after 1, 2, and 3 weeks storage at + 4 °C. The left LD muscles were vacuum packaged, frozen at -20 °C and kept frozen until preparation for sensory evaluation. No significant differences were found in carcass quality (carcass weight, EUROP carcass conformation and fat scores), meat colour stability and water-holding capacity of LD samples when comparing the two treatment groups LPD and CPD. However, sensory panellists judged samples from LPD fed reindeer to have a tendency (not significant) to be more tender (P= 0.06) and juicy (P=0.07) than the meat samples from CPD fed reindeer. No flavour differences were found when comparing meat samples from the two treatment groups.

Doctor of Philosophy
Department of Grain Science and Industry
Keith C. Behnke
A series of experiments was conducted to compare methods used to evaluate the durability of animal feed pellets, as well as to investigate the potential for modeling the effects of formulation and processing factors on both pellet durability index (PDI) and pelleting energy consumption, measured in kilowatt hours per ton (kWh/ton). Seven different factors, including ground corn particle size, added fat level, inclusion of distillers dried grains with solubles (DDGS), feed rate, steam conditioning temperature, conditioner retention time, and pellet die thickness (L:D ratio) were examined. Each factor was evaluated at two levels, and treatments were developed in order that all factor to factor comparisons could be made. Pellet samples were analyzed according to the standard method as described in ASAE S269.4, a modification of this method, and by using the NHP100 pellet tester set to each of its four testing intervals (30, 60, 90, and 120 seconds). The standard method was found to provide the most consistent and repeatable determinations of pellet durability, and was found to correlate well with the modified method, as well as with the NHP100 results at 30 and 60 seconds. Physical attributes of feed pellets, such as pellet hardness, bulk density, and moisture content were found to have significant, but weak correlations with pellet quality. Pellet quality was found to be significantly influenced by all factors other than ground corn particle size and feed rate. Higher fat level, lower conditioning temperature, and the thinner pellet die most significantly lowered pellet quality, with increasing effect respectively. A regression model was developed that was able to predict pellet durability within an average of 1.1 PDI. Pelleting energy consumption was found to be significantly influenced by all seven factors, with the higher fat level, thinner pellet die, and higher conditioning temperature most improving efficiency, with increasing effect respectively. A regression model was developed that was able to predict energy consumption within an average of 0.3 kWh/ton. The successful creation of regression equations demonstrates that there is potential for modeling and optimizing pellet quality and energy consumption within a pelleting operation.

The aim of this thesis was to evaluate the feeding and nutrition of tropical farmed fish and shrimp, targeting its applicability to aquaculture farming. The study of the actual panorama of aquafeed quality for tilapia Oreochromis niloticus and shrimp Litopenaeus vannamei farmed in Brazil showed that the proximate compositions between the analyzed feeds were mostly consistent with the declared values from the manufacturers, however, the feed water stability showed the opposite; the in vitro pH-stat species-specific method to determine the protein degree of hydrolysis (DH) showed to be a useful tool to evaluate feed quality; and NIRS technique can be used in many applications throughout the aquafeed industry, being an efficient tool for rapidly assessing feed quality in terms of DH. A second study evaluated the acid-insoluble ash (AIA) and chromic oxide (Cr2O3) as inert markers and feed processing method (industrial extruded vs. laboratory cold pelleted) to determine apparent digestibility coefficient (ADC) of dry matter and crude protein of juvenile L. vannamei. The AIA showed to be an effective natural endogenous marker for digestibility trials with L. vanammei, however, for commercial feeds attention should be paid to feed AIA level; the extruded feed showed better animal performance than the cold pelleted feed, however, ADC of both feeds were not significantly different from each other. Further, two feeding trials were conducted with juvenile cobia Rachycentron canadum: (1) feeding trial conducted within floating net cages to test the nutritional efficacy of different dietary feeding regimes ranging from the use of trashfish, in-house formulated feeds, to dry commercial extruded marine fish feed; and (2) feeding trial conducted within indoor water-recirculated tanks to test the nutritional efficiency of different potential dietary fishmeal replacers within dry in-house prepared diets. Generally, fish performance was superior in the net-cage feeding trial compared with the indoor water-recirculated tank trial; overall, the fish growth and performance of the experimental diets were very similar, showing that the alternative ingredients could be included and replace part (50%) of the fishmeal component; the results from both trials concluded that the cobia requires practices diets with high levels of crude protein and lipid, and the inclusion of alternative plant-based and terrestrial animal protein sources was possible; the quantitative essential amino acid (EAA) requirement values estimated by the protein accretion method was highly correlated to the average of each of the EAA requirement for the species of carnivorous fish reported in the literature, and could be recommended for formulation of commercial feed for cobia R. canadum. Finally, a tentative to quantify the total sulfur amino acid requirement of juvenile Florida Pompano Trachinotus carolinus, was performed using combinations of various soybean protein products in order to develop cost-effective and environmentally-friendly diets. Although there was an apparent tendency in the results, the range of methionine levels employed in this study may not have been broad enough to accurately measure the dietary concentration necessary to estimate the total sulfur amino acid requirement; in addition, high variation results among the three replicates per diet did not provide sufficiency robustness for its estimation; this study within 45 days should not have been enough to show significant differences among the treatments. Long term feeding trials would be recommended from fingerling/juvenile to market size with full nutritional and economic evaluation of results.
O objetivo dessa tese foi avaliar a alimentação e nutrição de peixes e camarões tropicais cultivados, visando a sua aplicação à aquicultura. O estudo do atual panorama da qualidade das rações para tilapia e camarão cultivados no Brasil mostrou que a maioria das composições proximais das rações analisadas foram consistentes com os valores declarados pelos fabricantes, porém, a estabilidade das na água mostrou-se o oposto; o método in vitro pH-stat com enzimas espécie-específica, para determinação do grau de hidrólise da proteína (DH), mostrou ser uma ferramenta útil para avaliar a qualidade das rações; a técnica da espectrofotometria do infravermelho próximo (NIRS) pode ser usada em várias aplicações na indústria de alimentos aquáticos, sendo uma ferramenta eficiente para avaliar rapidamente a qualidade dos alimentos em termos de DH. Um segundo estudo avaliou a cinza insolúvel em ácido (AIA) e óxido de cromo (Cr2O3) como marcadores inertes, além de métodos de processamento de alimentos (extrusado industrial vs. peletizada a frio no laboratório) para determinar o coeficiente de digestibilidade aparente (ADC) da matéria seca e proteína bruta de juvenis de L. vannamei. O AIA mostrou ser um marcador endógeno natural eficaz para ensaios de digestibilidade com L. vanammei, no entanto, atenção especial deve ser dada aos níveis de AIA nas rações comerciais; a ração extrusada teve a melhor performance dos animais, porém, os valores de ADC entre as rações não foram diferentes significantemente. Além disso, dois experimentos de alimentação foram conduzidos com juvenis de beijupirá Rachycentron canadum: (1) experimento realizado em tanques-rede flutuantes para testar a eficácia nutricional de diferentes regimes alimentares, variando entre rejeito de pesca, rações preparadas em laboratório, e ração comercial extrusada; e (2) um experimento realizados em tanques com recirculação de água para testar a eficiência nutricional de diferentes potenciais substitutos de farinha de peixe, com dietas completadas preparadas em laboratório. Em geral, o desempenho dos peixes foi superior no experimento nos tanques-rede, comparado com o experimento nos tanques de recirculação de água; no geral o crescimento e performance dos peixes das dietas experimentais foram bem similares, concluindo que ingredientes alternativos podem ser incluídos e substituírem parte (50%) da farinha de peixe das rações; os resultados de ambos os estudos concluíram que o beijupirá requer dietas práticas com alto teores de proteína bruta e lipídeos, e a inclusão de fontes proteicas de origem vegetal e animal foi possível. Os valores quantitativos das exigências de amino acido essenciais (EAA) estimados pelo método de acreção de proteína na carcaça foram altamente correlacionados com as médias de exigência de cada EAA das as espécies de peixes carnívoros encontrados na literatura, e pode ser recomendado para a formulação de ração comercial para beijupirá R. canadum. Por ultimo, uma tentativa de quantificar as exigências de amino ácidos sulforosos totais para Florida Pompano Trachinotus carolinus, foi realizada utilizando combinações de vários ingredientes proteicos a base de soja, a fim de desenvolver dietas de baixo custo e ecologicamente sustentáveis. Embora houve uma tendência clara nos resultados, os intervalos dos níveis de metionina utilizados nesse estudo podem não ter sido amplos o suficiente para medir com precisão a concentração alimentar necessária para estimar a exigência dos de amino ácidos sulforosos totais; além disso, a alta variação entre as replicas não forneceu uma estimativa robusta; este estudo de 45 dias não deve ter sido suficiente para mostrar diferenças significativas entre os tratamentos.

The use of vacuum coating is mostly limited to production of high fat containing extruded aqua and pet diets. The physical characteristics of extrudates are favourable for vacuum coating due to their high porosity and durability. However, with pelleted feed for broilers, there are potentially several opportunities, but there are also challenges; these are explored here. The opportunities identified were inclusion of high level of oils, protected delivery of feed additives (e.g., enzymes, probiotics, vaccines, etc.), improved and safe use of offensive feed additives and improvement of shelf-life of feed and additives. Challenges include the relatively high density of pellets (low porosity) which limits liquid infusion, increased processing cost and decreased feed throughput. However, feed ingredients selection and alternating processing variables (temperature, moisture, die specifications etc.) were deemed to overcome the challenges of low porosity. Three experiments were conducted to evaluate the use of vacuum coating in pelleted feed. In the first experiment, the effect of particle size on post-pellet oil absorption (OA), porosity, pellet durability index (PDI) and bulk density were investigated. The three particle sizes for three grains (wheat, barley and corn) were pelleted using a 4.7 mm die to get whole grain (WP), coarse (CP), and fine (FP) grind pellets. The pellets were coated with 15% canola oil without (VC-) and with (VC+; 0.3 bar) vacuum coating. The grain type was found to have a significant effect on the particle size when ground through either fine (3.2 mm) or coarse (6.4 mm) screen. With coarse grinding, the mean particle size was 1896, 1290 and 1057 µm, respectively for barley, wheat and corn; with fine grinding, the mean particle size was 1153, 767 and 732 µm, respectively. Porosity of CP from wheat and corn was significantly (P<0.01) higher than WP and FP. For barley, there was no difference in porosity of CP and FP but both were significantly higher than WP. For wheat, OA of CP was highest (P<0.01), but no significant difference was found between FP and WP. However, for barley, higher OA was found in FP followed by CP and WP. In corn, OA of CP was higher than for FP or WP. Vacuum coating (VC+) improved (P<0.01) OA of all pellets compared to VC-. Porosity was positively correlated with OA and negatively correlated to PDI and bulk density. Overall, the first experiment suggested that alteration of particle size and grain type could be the options for improving the oil absorption by vacuum coating. A second experiment was conducted to observe the effect of enzyme addition method (EAM; E-, without enzyme; PreE+, Pre-pellet addition of enzyme; PosE+, post-pellet addition of enzyme), conditioning temperature (CT; 65 or 95°C) and coating method (CM; VC- or VC+) on broiler performance when fed wheat-rye-based diets. Enzyme addition (pre or post-pellet addition in comparison to without enzyme) significantly improved (P<0.01) the body weight at 21 and 35d. Higher CT (95°C) improved feed conversion ratio (FCR) in both starter (P<0.01) and grow/finish phase (P=0.04) and PDI of both starter and grow/finish pellets (P<0.01) when compared to low CT (65°C). Vacuum coating did not have any effect on the diet extract viscosity, animal performance or digesta viscosity in either of the phases. However, with post-pellet vacuum coating, there was high retention of xylanase activity after processing. Vacuum coating significantly (P<0.05) reduced the relative length of small intestine of broilers at 21d but not at 35d. In the third experiment, broiler grow/finish diets were stored in an incubator (37°C) to see if vacuum coating can improve the shelf-life of feed. The results showed post-pellet vacuum-coated pellets retained higher enzyme activity after 15 days of storage. Although no effect of vacuum coating on animal performance was observed, vacuum coating was able to protect the enzyme during processing and storage. Further work needs to be done to translate these benefits to improve animal performance, which might be achieved using various vacuum coating and processing conditions, and bioactives.

3D printing (additive manufacturing) has become a popular method to create three-dimensional objects due to its high efficiency and is easy to operate. 3D printing of continuous fiber reinforced polymers has been a challenge. The fused deposition modeling (FDM) processes for this purpose were proposed and made possible only several years ago. The 3D printed continuous fiber reinforced polymers are able to improve the mechanical properties by leaps and bounds. In this paper, we aim to investigate the possibility of further improve the mechanical properties of 3D printed continuous fiber reinforced polymers by adding nano fillers to the polymer matrix. In experiment, the Kevlar fiber is chosen to be the continuous fiber material, and nylon 6 (PA 6) is chosen to be the polymer matrix material. Carbon nanotubes (CNTs) and graphene nano platelets (GNPs) nanoparticles are first mixed with nylon 6 pellets to make nanocomposites. The nanocomposites are then extruded into filaments for 3D printing. During the 3D printing process, both Kevlar filament and nanocomposite filament are fed through the printing nozzle and deposited on the platform. Tensile specimens are made from pure PA 6 and four types of nanocomposites, namely, 0.1wt% CNT/PA 6, 1wt% CNT/PA 6, 0.1wt% GNP/PA 6, 1wt% GNP/PA 6. By incorporating four layers of Kevlar fiber, which leads to the weight percentage of about 9% for Kevlar fiber in materials, fiber composite tensile specimens are made from Kevlar/PA 6 composite and four fiber reinforced nanocomposites, namely, Kevlar/0.1%CNT/PA 6, Kevlar/1%CNT/PA 6, Kevlar/0.1%GNP/PA 6, and Kevlar/1%GNP/PA 6. The tensile tests reveal that CNTs filled PA 6 nanocomposites show less significant improvements in mechanical properties as compared to the GNP filled PA 6. With only 0.1wt% of GNP, the tensile modulus improves by 101%, and with 1wt% of GNP, the modulus improves by 153%. The results also indicate that although Kevlar fibers dominate the main mechanical properties of the printed composite materials, the existence of GNP nano fillers also provide noticeable contribution to the enhancement of tensile strengths and moduli, while the effect of CNTs is much less pronounced.