Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-15T13:27:01Z No. of bitstreams: 2 Dissertação - Cristielle Nunes Souto - 2015.pdf: 2071042 bytes, checksum: 7524975d113f5a11986a4d3075c22552 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-15T13:28:38Z (GMT) No. of bitstreams: 2 Dissertação - Cristielle Nunes Souto - 2015.pdf: 2071042 bytes, checksum: 7524975d113f5a11986a4d3075c22552 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-10-15T13:28:38Z (GMT). No. of bitstreams: 2 Dissertação - Cristielle Nunes Souto - 2015.pdf: 2071042 bytes, checksum: 7524975d113f5a11986a4d3075c22552 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-03-03 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / This study aimed to evaluate the feasibility of replacing soybean meal by shrimp meal in diets for tambaqui. In trial I, the coefficient of total tract apparent digestibility of the dry matter, protein, amino acids, fat, chitin, and organic matter was determined for shrimp meal, while in trial II, the growth performance of tambaqui fed diets containing graded levels of shrimp meal was evaluated. Triplicates groups of Tambaqui fingerlings with 2.7±0.72g mean initial weight were randomly assigned to 20 310L-aquaria and fed five diets that the soybean meal protein was replaced by shrimp meal protein at 0.0, 12.5, 25, 50 and 75%. The parameters evaluated were weight gain, feed intake, feed conversion ratio, specific growth rate, protein efficiency ratio, protein retention and diet with lower valuation was represented by higher replacement. Carcass chemical composition, haematology and serum biochemistry were analysed as well. Chitin seems not to be digested by tambaqui and tended to reduce the CTTAD of dry matter and organic matter. The CTTAD of amino acids were high and correlated to the CTTAD of protein. Fish fed diets containing the 48.6% shrimp showed the highest ash content (P<0.05). Haematology of tambaqui was not affected by shrimp meal inclusion. However, the number of thrombocytes and eosinophils increased in fish fed the diets with the highest shrimp meal level. The gain in weight was low with the highest level of shrimp meal inclusion, however, no effect of shrimp meal inclusion to the diets was observed in others growth parameters. Total serum protein and globulin levels increased according to the increase of shrimp meal levels (P<0,05). In sum, shrimp meal protein seems to be able to replace the soybean meal protein up to 75% in diets for tambaqui without reducing the growth performance or health status. A possible immune enhancer effect of natural chitin from shrimp meal may take place in tambaqui; however further studies are needed to confirm our hypothesis. / Esse estudo objetivou avaliar a viabilidade da substituição da proteína do farelo de soja (FS) pela proteína dafarinha de camarão (FC) em dietas para o tambaqui. No primeiro ensaio foi determinado a digestibilidade aparente da matéria seca, proteína, aminoácidos, extrato etéreo, quitina e matéria orgânica da farinha de camarão, enquanto no segundo ensaio, o desempenho produtivo dos tambaquis alimentados com diferentes níveis de inclusão da farinha de camarão foi avaliada. Alevinos de tambaquicom peso inicial de 2,7±0,72g foram aleatoriamente distribuídos em aquários de 310L, totalizando 20 aquários, sendo 3 repetições por tratamento. Os tratamentos foram constituídos pela substituição da proteína do farelo de soja pela farinha de camarão nos níveis de 0,0;12,5; 25; 50 e 75%. Os parâmetros avaliados foram ganho de peso, consumo de ração, taxa de conversão alimentar, taxa de crescimento específico, taxa de eficiência proteica, taxa de retenção proteica e custo das dietas. Composição da carcaça, hematologia e bioquímica sérica também foram avaliadas. A quitina apresentou-se completamente indigestível e tendeu a diminuir os coeficientes de digestibilidade aparente (CDA) para matéria seca e matéria orgânica. Os CDAs dos aminoácidos apresentaram-se altos e não correlacionados ao CDA da proteína. O ganho em peso apresentou valor reduzido com o maior nível de inclusão de farinha de camarão, entretanto os demais parâmetros de desempenho não foram afetados pelo aumento da inclusão da farinha de camarão. As dietas com maiores níveis de inclusão apresentaram menor custo de produção. Os peixes alimentados com dietas contendo 48,6% de inclusão da farinha de camarão apresentaram alto conteúdo de matéria mineral na carcaça (P<0,05). Os parâmetros hematológicos não foram afetados pela inclusão da farinha de camarão. Entretanto, os números de trombócitos e eosinófilos apresentaram-se aumentados nos peixes alimentados com o maior nível de inclusão. A proteína e globulina sérica apresentaram-se aumentados (P<0,05) a medida que aumentou os níveis de inclusão da farinha de camarão nas dietas. Dessa forma, a proteína do farelo de soja pode ser substituída pela proteína da farinha de camarão em até 75% sem reduzir o desempenho produtivo e higidez dos animais. Um possível efeito imunomodulador da quitina natural da farinha de camarão foi notado; porém são necessários mais estudos para confirmar essa hipótese.

Submitted by Marilene Donadel (marilene.donadel@unioeste.br) on 2018-09-04T19:47:14Z No. of bitstreams: 1 Iury_Melo_2016.pdf: 767803 bytes, checksum: f889d1e786edb063a7b1a1c0529113a8 (MD5) / Made available in DSpace on 2018-09-04T19:47:14Z (GMT). No. of bitstreams: 1 Iury_Melo_2016.pdf: 767803 bytes, checksum: f889d1e786edb063a7b1a1c0529113a8 (MD5) Previous issue date: 2016-03-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The phytogenic additives have shown positive results in chemicals replacement such as antibiotics in animal production, because it does not have cumulative effects on muscle and does not favor the selection of super-resistant bacteria. The experiment was conducted in two stages. The first stage aimed to evaluate the apparent digestibility coefficients (ADC) of protein, lipids, energy and mineral matter in 180 tilapia fish (40.0 ± 5.7g) fed with three diets (0; 100; and 200 mg kg-1) and four replications along 30 days. The second experiment aimed to determine the optimal inclusion of the additive through productive performance and by conducting hematologic, carcass centesimal composition analyses, as well as muscle and intestine morphometry. 240 fingerlings with average weight of 1.07 ± 0.07g were randomly distributed in 30 tanks of 138 liters, in recirculation system equipped with mechanical, biological filter and ultraviolet light to purify water for 60 days. The design was completely randomized with five treatments (0; 50; 100; 150 and 200 mg kg-1 additive) and six repetitions, each experimental unit consisting of eight fish. In both experiments the diets had approximately 38% crude protein and 3000 kcal of digestible energy. Growth performance (weight gain, feed conversion, daily weight gain, protein efficiency ratio, condition factor, survival, protein retention efficiency, visceral fat, hepatosomatic index, specific growth rate and lot uniformity), fish centesimal composition (moisture, crude protein, ether extract and ash), hematological indices, muscle fibers distribution and intestinal villus morphometry (villus height and epithelium thickness) were evaluated. The ADCs showed significant positive differences (p <0.05) between treatments. According to zootechnical, hematological, centesimal and histological parameters no differences were observed between treatments. We concluded that 100 kg-1 of Sangrovit® additive improves the apparent digestibility coeficient of protein, lipid, energy and mineral matter for tilapia. / Os aditivos fitogênicos vêm apresentando resultados positivos em substituição aos produtos químicos como os antibióticos na produção animal, pois não apresentam efeitos acumulativos no músculo nem favorecem a seleção de bactérias super-resistentes. O experimento foi conduzido em duas etapas. A primeira etapa objetivou avaliar os coeficientes de digestibilidade aparente (CDa) da proteína, lipídeos, energia e matéria mineral de 180 tilápias (40,0 ± 5,7g) alimentadas com três dietas (0; 100; e 200 mg kg-1) e quatro repetições, durante 30 dias. O segundo experimento objetivou determinar a inclusão ideal do aditivo através do desempenho produtivo, e realizadas análises: hematológicas, composição centesimal da carcaça, bem como morfometria do músculo e intestino. Foram utilizados 240 alevinos com peso médio de 1,07 ± 0,07g, distribuídos aleatoriamente em 30 tanques de 138 litros, em sistema de recirculação, equipado com filtro mecânico, biológico e lâmpada ultravioleta para limpeza da água, durante 60 dias. O delineamento utilizado foi o inteiramente ao acaso com cinco tratamentos (0; 50; 100; 150 e 200 mg kg-1 de aditivo) e seis repetições, sendo cada unidade experimental composta por oito peixes. Em ambos os experimentos as dietas apresentavam aproximadamente 38% de proteína bruta e 3000 kcal de energia digestível. Avaliou-se o desempenho zootécnico (ganho em peso, conversão alimentar aparente, ganho em peso diário, taxa de eficiência proteica, fator de condição, sobrevivência, eficiência de retenção proteica, gordura visceral, índice hepatossomático, taxa de crescimento específico e uniformidade do lote), a composição centesimal dos peixes (umidade, proteína bruta, extrato etéreo e cinzas), os índices hematológicos, as distribuições das fibras musculares e morfometria das vilosidades intestinais (altura do vilo e espessura do epitélio). Os CDAs apresentaram diferenças significativas positivas (p<0,05) entre os tratamentos. Para os parâmetros zootécnicos, hematológicos, centesimais e histológicos não foram observadas diferenças entre os tratamentos. Conclui-se que 100 mg kg-1 do aditivo Sangrovit® melhora o coeficiente de digestibilidade aparente da proteína, lipídeos, energia e matéria mineral para tilápias.

Master of Science / Department of Animal Sciences and Industry / James S. Drouillard / Three trials were conducted using dried distiller's grains with solubles (DDGS) to evaluate effects on feedlot performance, carcass characteristics, ruminal fermentation, and diet digestibility in cattle fed steam-flaked corn-based diets. In trial 1, crossbred yearling heifers were used in a finishing trial to evaluate interactions between corn-DDGS feeding levels and roughage source (alfalfa hay vs corn silage) in terms of impact on feedlot performance and carcass characteristics. Experimental diets were based on steam-flaked corn and contained 0% DDGS with 6% alfalfa hay (AH), 0% DDGS with 10% corn silage (CS), 25% DDGS with 6% AH, or 25% DDGS with 10% CS (DM basis). Results indicated no interaction between levels of DDGS and roughage source. Heifers fed DDGS as a partial replacement for steam-flaked corn had similar growth performance and carcass merit compared to heifers fed diets without DDGS. Corn silage and alfalfa hay were comparable roughages when a portion of steam-flaked corn was replaced with DDGS. The second trial was a companion metabolism study in which ruminal fermentation characteristics and diet digestibility were examined in 12 cannulated Holstein steers fed steam-flaked corn finishing diets with or without DDGS, using alfalfa hay or corn silage as roughage sources. Diets were similar to those fed in the performance study and consisted of steam-flaked corn with 0 or 25% DDGS (DM basis) and 6% AH or 10% CS (DM basis). Feeding DDGS decreased ruminal pH and ruminal ammonia concentrations, and digestion of DM and OM were less compared to diets without DDGS. The decrease in digestibility was largely attributable to poorer digestion of CP and, to a lesser extent, a reduction in starch digestion. The third study was designed to investigate effects of pH (5.0, 5.5, and 6.0) on in vitro fermentative activity by ruminal microorganisms from cattle adapted to a finishing diet containing 25% DDGS (DM basis). Higher pH led to greater dry matter disappearance in vitro (P < 0.01). DDGS can be an effective substitute for steam-flaked corn. Efforts to address low ruminal pH and low ruminal ammonia may prove beneficial for improving value of DDGS as cattle feed.

The objectives of this thesis were: 1) to assess the iron status of piglets, 2) to thoroughly evaluate the blood profile, growth performance, and tissue mineral concentration of young pigs during the pre and postweaning periods after receiving various dosages of iron (0, 50, 100, 200, and 300 mg iron) at birth, 3) as well as evaluate the effects of an additional iron injection before weaning on hematological measures, growth performance, and tissue mineral concentration postweaning. In the initial experiment, there was a 60% incidence of iron deficiency at weaning after administration of a 150 mg iron injection at birth. Also at weaning, hemoglobin concentration was negatively correlated with BW and BW gain (r = -0.53, P < 0.0001, and r = -0.60, P < 0.0001 respectively). In the second experiment, pigs that were not injected with iron at birth had a major reduction in hematological measures, growth performance, and tissue iron concentration until d 52 where iron status was recovered but growth was not. Overall, ADG was improved in a linear and quadratic manner (P = 0.02 and P = 0.01 respectively) as the iron dosage increased with the largest improvement from the 0 mg to 50 mg iron treatment. The improvement observed in ADG let to similar increases (P = 0.02 and P = 0.01 respectively) in final BW as iron dosage treatments increased. Hemoglobin (Hb) concentration improved (P = 0.01) with increasing injectable iron as early as d 1 and continued to d 38, thereafter (d 52) no differences in Hb concentration were observed. Iron concentration for all tissues (liver, spleen, heart, and kidneys) at weaning was greater (P ≤ 0.01) as the iron dosage increased. In the third experiment, pigs that were supplemented with an additional iron injection 4 days before weaning had an increased ADG for the overall experimental period (31 to 34 d). The improved ADG during the experiment led to a heavier (P < 0.001) final BW (~1 kg) for pigs injected with an additional iron injection. At weaning, pigs injected with a second iron injection had higher (P < 0.001) hemoglobin concentration and other complete blood count measures. The improved Hb concentration observed at weaning continued 14 days later (P ≤ 0.02). Additionally, liver iron concentration was greater (P = 0.02) at weaning for the pigs receiving an additional iron injection. In summary, the initial iron injection administered at birth may not be adequate to satisfy all individual iron requirements of piglets before weaning, however, hematological measurements and tissue iron concentration do improve as the iron dosage increases at birth. Furthermore, injecting an additional iron injection before weaning improves nursery growth performance.

Results from the present study found for the first time that the use of bacterial strains of Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium thermophilum, and Enterococcus faecium from the commercial product PrimaLac® had the potential to act as a possible probiotic for juvenile red drum. The addition of PrimaLac® probiotics [whether as a water-soluble probiotic (WSP) or in a probiotic enhanced starter feed (PESF)] reduced mortality (%M), enhanced growth rates (MW, LT, SGR, and DGR), improved feed conversion efficiencies (FCEs), and physical condition factors in the juvenile red drum. Improvement was quantified using external morphological condition indices (MCIs) and blood physiological condition indices (PCIs). Results showed a strong positive relationship between MCIs and PCIs, which suggested that probiotics treated fish were in better health (lower MCIs) with lower fasting blood glucose and lactate levels than control fish. Addition of probiotics also resulted in improved water quality (lower nitrate, nitrite, and ammonia) in the treatment tanks compared to controls. Application of PrimaLac® probiotics on the morphology and histology of three different regions of the intestine (proximal, mid-and distal) improved intestinal length (Li), mass (Mi), and digesta mass (Md). In 5μm histological sections examined for differences among treatments (probiotics vs. controls), five variables within each intestinal region were also quantified: (i) perimeter ratio (PR) between the internal perimeter (IP) of the intestinal lumen and the external perimeter (EP) of the intestine where, PR = IP/EP; (ii) width of lamina propria (wLP); (iii) thickness of the muscle layer (tM); (iv) the number of goblet cells per segments (GC); and (v) height of enterocytes (hE). Overall, Li and Mi significantly increased by 13.4 ± 1.2% and 11.8 ± 0.9%, respectively, and Md decreased by 33.2 ± 1.21% compared to controls. Significant increases in microvilli heights, PR (by 21.3 ± 1.2%), tM (by 18.4 ± 0.9%), and increased numbers of GC (by 35.1 ± 2.8%) provided evidence that bacteria species from PrimaLac® (whether in WSP or PESF) affected the intestinal histomorphology of juvenile red drum. Collectively, these changes were partially responsible for increased feed assimilation (supported by reduced digesta) and improved overall juvenile red drum growth and condition. These results will add significantly to the limited database on how probiotics, as possible standard practice at the fish farm, may offer significant benefits for fish production and fish health. Addition of probiotics will also be of benefit to most aquaculture species and not only for red drum, but also for other high-value carnivorous species, such as Atlantic salmon, without threat to natural populations or damaging fisheries-based ecosystems that are already on the edge of collapse from over fishing and pollution.

To maximize the economics of a new commercial broiler cross, research on its nutritional specifications is necessary. Study 1 investigated the effects of feeding four amino acid densities (AAD) on performance and yield of Cobb MV × Cobb 500 broilers at d 33 and 36. Data demonstrated a stepwise decrease in feed conversion ratio (FCR) as AAD level increased. Improvements in performance, processing, and economic return were observed when feeding higher AAD levels. Study 2 estimated the digestible lysine (dLys) requirements of Cobb MV × Cobb 500 broilers from d 0-14 and evaluated the impact of varying starter dLys levels on their performance, processing, and economic return during a 42 d grow-out. Data suggested that d 0-14 dLys requirements varied based on broiler response and statistical model. Improvements in overall performance was observed when feeding ≥1.12% dLys during the starter phase. The greatest economic return was associated with feeding starter dLys of 1.20%. Due to the potential interaction between AA and apparent metabolizable energy (AME), Study 3 examined the response of Cobb MV × Cobb 500 to varying dLys and AME levels from d 0-14 on d 0-42 performance and processing. A dLys × AME interaction was observed for d 0-28 FCR and for dLys and AME for early performance parameters. However, this significance was lost by the end of the study. Due to the variation in broiler response to feeding strategies at different ages, Study 4 evaluated the impact of varying dLys and AME levels from d 14-28 on performance and processing of 42-day old Cobb MV × Cobb 500 broilers. Data demonstrated significant dLys × AME interactions for d 14-28 and 14-35 FCR, as well as significances for main effect of dLys and AME for performance and processing (d 42). Feeding grower diets formulated to 1.18% dLys + 3028 kcal/kg AME was the most profitable diet. Overall, this research demonstrates that higher AAD improved broiler performance, especially ≥1.12% starter dLys. Varying dLys and AME during the starter phase did not affect performance at d 42; however, it did when this regimen was exercised during the grower phase.

No description available.

L'aquaculture est en pleine expansion et fournit aujourd'hui la moitié des produits aquatiques destinés à la consommationhumaine. Elle constitue ainsi un secteur clé pour le maintien et l'amélioration de la sécurité alimentaire dans lemonde. Le développement de l'aquaculture est étroitement lié à celui des formules alimentaires. Ces dernières années,la part des farines de poisson dans la formulation des aliments a particulièrement diminué au profit des farines d'originevégétale pour répondre aux nombreuses contraintes économiques et environnementales. Néanmoins, ces matièrespremières sont moins adaptées aux besoins nutritionnels des poissons carnivores et leur utilisation peut entraîner unebaisse des performances de croissance et d'efficacité alimentaire. L'ajout d'additifs et d'ingrédients fonctionnels devientalors indispensable. Les hydrolysats protéiques issus des co-produits de la pêche et de l'aquaculture sont des ingrédientsà fort potentiel appétence, nutritionnel et bioactif. Ces ingrédients sont des mélanges complexes riches en peptides hydrolytiqueset en acides aminés libres, mais dont la composition varie en fonction de l'origine de la matière première etdes paramètres d'hydrolyse appliqués lors de leur fabrication. Au cours de ces travaux de thèse, nous avons développéet mis en pratique des outils permettant d'approfondir la caractérisation structurale et les propriétés fonctionnellesdes hydrolysats de protéines. Dans un premier temps, nous avons développé une méthode analytique basée sur unenormalisation des échantillons suivie d'une détermination de l'abondance et de la richesse en peptides par chromatographied'exclusion stérique et chromatographie liquide couplée à la spectrométrie de masse de type électro-spray,respectivement. Les résultats présentés sous forme d'un diagramme 2D permettant de classer et comparer facilementles hydrolysats de protéines de forme galénique, d'origine et de process différents. Nous avons également développé unoutil in vitro sur l'intestin de bar européen, Dicentrarchus labrax, permettant de déterminer les activités myotropesdes hydrolysats. Nous avons pu notamment démontrer que l'hydrolysat de crevettes possède une plus forte activitémyotrope que les hydrolysats de poissons et que cette activité est portée par un pentapeptide KNPEQ clivé à partirde l'hémocyanine lors du process d'hydrolyse appliqué sur les co-produits de crevette. Enfin, dans un second temps,un conditionnement alimentaire de 65 jours a été conduit chez le bar européen nourri avec un aliment pauvre en farinede poisson supplémenté en hydrolysat de différentes origines et couplé à une analyse d'expression génique (approcheen RNA-Seq Illumina). Cette étude a permis de montrer que les hydrolysats de protéines appliqués sur un alimentfaible en farine de poisson (5%) sont capables de restaurer des performances de croissance équivalentes à celles d'unrégime contenant 20% de farine de poisson mais qu'ils portent par ailleurs des propriétés fonctionnelles spécifiques.Il a également été montré que le mélange des deux hydrolysats permet de moduler les transcriptomes intestinal ethépatique de façon plus profonde que lorsque que les hydrolysats sont utilisés séparément. Ces résultats confirmentl'intérêt des hydrolysats de protéines pour la formulation d'aliment à faible teneur en farines de poisson et apportentde nouveaux outils de caractérisation de ces ingrédients complexes, qui seront utiles pour leur optimisation et leurstandardisation ainsi que pour la compréhension de leurs mécanismes d'action chez les poissons. / Aquaculture is a key sector for supporting and improving the food security worldwide. The global production of farmedfish and shrimp has grown dramatically over the past decades and now contributes to half of the aquatic productsintended for human consumption. Aquaculture will require feeds to support its growth but availability of some raw materialssuch as fish meal are limited. The use of fish meal in aquafeed has particularly declined in favor of plant proteinsources to fit with economic and environmental constraints. But plant proteins do not meet perfectly the nutritionalrequirements of carnivorous fish and their utilization often results in lower growth and feed performances. Proteinhydrolysates manufactured from fishing and aquaculture co-products are ingredients with a high palatable, nutritionaland bioactive potential. They are rich in hydrolytic peptides and free amino acids, but they are complex mixtureswhose composition could vary according to raw material origin and hydrolysis parameters. During this PhD study, wedeveloped and implemented tools to further characterize the structure and functional properties hydrolysates. On afirst step, we developed a fast methodological tool based on sample standardization, followed by the determination ofthe abundance and richness of peptides using size exclusion chromatography and liquid chromatography coupled toelectro-spray mass spectrometry, respectively. We merged the results into a 2D diagram that made it easy to classifyand compare hydrolysates having different galenic, origin and process. We also developed a tool on isolated intestinefrom European seabass (Dicentrarchus labrax ) to rank protein hydrolysates according to their myotropic property.We demonstrated that shrimp hydrolysate showed a higher myotropic activity than fish hydrolysates and that thisactivity was carried by a unique pentapeptide KNPEQ produced by the enzymatic clivage of haemocyanin during thehydrolysis process applied on shrimp co-products. On a second step, a 65-day feeding trial was conducted in Europeanseabass fed a low fish meal diet supplemented with protein hydrolysates of different origin, and coupled to a studyof the intestine and liver transcriptomic response (Illumina RNA sequencing). It has been shown that protein hydrolysatesincluded in a low fish meal diet (5%) restored growth performances to the same level than a diet containing20% of fishmeal, and that they exhibited very specific functional properties. These results showed that a mixture oftwo hydrolysates impacted more deeply the intestine and liver transcriptomes than hydrolysate tested alone. ThisphD study confirmed that protein hydrolysates are very interesting candidates for formulating low fish meal feed andoffer new tools for characterizing such complex ingredients, which will be useful to optimize and standardize proteinhydrolysate while understanding their mechanisms of action in fish.

A whole-cell DHA-rich algal product (A-DHA, provided by Evonik Industries) that is rich in DHA (125 mg DHA/g dry matter) is a possible replacement for fish oil in salmonid diets. The nutrient digestibilities of the algal product were measured in rainbow trout in freshwater and in Atlantic salmon in saltwater (32-33 ppm). In experiment 1, rainbow trout (initial weight ~ 300g) were randomly assigned to 12 x 120 L tanks (n = 10 per tank). A reference diet containing 1% Celite as an indigestible marker and three test diets with increasing percentage of A-DHA substitution (6.67%, 13.33% and 20%) were fed. Feces were collected using a settling column and feed and feces analyzed for digestible dry matter (DM), gross energy (GE), ash, crude protein (CP), essential amino acids and total lipid. The digestibility of six long-chain fatty acids including 18:1n-9 (OA), 18:2n-6 (LA), 18:3n-3 (ALA), 20:4n-6 (ARA), 20:5n-3 (EPA) and 22:6n-3 (DHA) was measured. In experiment 2, Atlantic salmon (~170g) were randomly distributed to 12 fiberglass tanks (600L) with 106 fish per tank. The fish were assigned to four diets with the same levels of A-DHA inclusion as for rainbow trout and yttrium oxide (Y2O3) was used as an inert marker. Feces were collected by stripping and the digestibilities of DM, CP and lipid as well as OA, LA, ALA, ARA, EPA and DHA were determined. In experiment 1, the apparent digestibility of dietary DM, GE and lipid in rainbow trout declined significantly with increasing inclusion of A-DHA (P < 0.01). The inclusion of A-DHA had no effect on the digestibility of CP and ash as well as the availability of essential amino acids (P > 0.05). Furthermore, increased inclusion of A-DHA resulted in significantly lower digestibility of ARA, EPA and DHA (P < 0.05). A similar pattern was seen in the digestibility of OA, LA and ALA, although the effect of A-DHA inclusion was not statistically significant. Regression analysis revealed that nutrient contribution from A-DHA had significantly negative linear and quadratic effects on the apparent digestibility of DM, GE, and lipid. The inclusion levels of A-DHA had both significantly negative linear and quadratic effects on digestibility of LA and ALA, whereas only significantly negative linear effect was found on OA. Significantly negative linear and quadratic regressions were observed for the digestibility of ARA, EPA and DHA. The linear regression for CP was significantly negative and the regressions for the individual amino acids were not significant (P > 0.05). In experiment 2, dietary inclusion of A-DHA had a significantly negative effect on lipid digestibility in Atlantic salmon, at all inclusion rates whereas the significant negative effect on digestibilities of DM and CP was only observed in fish fed 20% A-DHA. The digestibilities of OA, LA, ALA and EPA were greater than 91%. In contrast, the apparent digestibilities of ARA and DHA decreased significantly with increasing substitution of A-DHA (P < 0.01). Significantly negative linear and quadratic regressions were found between nutrient contribution from A-DHA to the diets and apparent digestibility of DM, CP and lipid, so were LA, EPA and DHA. However, there were only significant quadratic regressions for OA, ALA and ARA, but not significant linear effects. Subsequently, a twelve-week feeding trial in rainbow trout was conducted to investigate the impact of replacing fish oil with A-DHA in canola-oil-based diets on the growth performance and fatty acid composition and retention. Four experimental diets containing only canola oil (CO; 13.5%), fish oil (FO; 13.5%), canola oil and fish oil (C+F; 7.4% and 6.1%, respectively) or canola oil and A-DHA (C+A; 15.5% and 6%, respectively) were formulated to contain 386.2 g/kg digestible crude protein and 17.58 MJ/kg digestible energy. In addition, the C+A diet was formulated to have the same DHA concentration as in the C+F diet. Each diet was fed to three tanks of rainbow trout (average initial weight of 70g; n = 17/tank) and the fish were fed to apparent satiation 2 times daily. At the end of the growth trial, all fish approximately tripled their weight. No significant differences were noted between the dietary treatments in growth performance as measured by final weight, average weight gain, feed intake, specific growth rate (SGR) and feed conversion ratio (FCR). Although FO and C+A fed fish tended to accumulate more lipids, final whole body lipid content did not differ significantly between dietary treatments (P = 0.11). The concentrations of EPA, DHA as well as total n-3 fatty acid were significantly higher in fish fed the FO diet than fish fed the other 3 diets. The C+A fed fish had lower EPA and higher DHA concentrations compared with the CO and C+F fed fish; however, the differences were not significant. Apparent retention of total lipid in the trout was not significantly influenced by treatments (P > 0.05). Similarly, dietary treatments had no significant effect on the apparent retention of total saturated fatty acids, total mono-unsaturated fatty acids, n-3 polyunsaturated fatty acids and n-6 polyunsaturated fatty acids. The retention of 18:4n-3 (SDA) was significantly higher (> 100%) in fish fed CO and C+A compared with fish fed FO and C+F (< 51%), indicating greater bioconversion of ALA to SDA in the CO and C+A fed fish than in FO and C+F fed fish. The retention of EPA in the CO and C+A fed fish was over 100%, suggesting a net synthesis of EPA in these treatment groups. In contrast, the EPA retention in the FO and C+F fed fish was 55 and 21%, respectively, which showed a tendency to be significantly lower than that in the other two groups (P = 0.09). The CO fed fish had significantly higher DHA retention than fish fed the other 3 diets. The DHA retention in the FO fed fish (112%) was numerically but not significantly higher than in the C+F (66%) and C+A fed fish (73%). Thus, feeding the C+A to rainbow trout resulted in DHA retention equal to feeding the C+F.

Experiments were conducted to assess effects of nursery feeding programs (using complex or simple diets, including or excluding antibiotics) on growth performance of barrows and gilts up to market weight (approximately 115 kg body weight), plasma levels of growth-related hormones, chemical body composition and carcass traits at market weight. Reducing nursery diet complexity decreased (P < 0.05) growth performance and plasma levels of triiodothyronine during the nursery period, but had no negative carry-over effects on growth performance or hormone plasma levels thereafter. Excluding antibiotics from nursery diets reduced nursery growth performance and plasma levels of insulin-like growth factor-1 and triiodothyronine but appeared to induce subsequent compensatory growth. In general, nursery feeding programs had no effect on body composition and carcass traits at market weight and no effect on wean-to-finish growth performance or carcass value at market weight. This represents an opportunity to improve profitability in commercial pork production. / Ontario Pork; The Ontario Ministry of Agriculture, Food and Rural Affairs; Canadian Agriculture and Agri-Food Swine Research Cluster