Avaliou-se a relação lisina digestível: energia metabolizável em dietas de machos castrados e marras dos 24 aos 50 kg. O delineamento experimental usado foi blocos ao acaso, com cinco tratamentos, oito repetições, um animal por unidade experimental no ensaio de desempenho e quarto repetições e um animal por unidade experimental no de metabolismo. Nos parâmetros sanguineos, foi usado delineamento inteiramente casualizado, quarto repetições por sexo e um animal por unidade experimental. Os tratamentos foram 0,80; 0,90; 1,00; 1,10 e 1,20% de lisina digestível. Avaliaram-se as características de desempenho, digestibilidade e metabolismo e os parâmetros sanguineos. Houve efeito quadrático do nível de lisina digestível no peso dos suínos e na conversão alimentar das fêmeas. O ganho de peso relativo, a eficiência de proteína bruta e a conversão alimentar melhoraram linearmente para machos castrados. Constatou-se efeito quadrático do aminoácido na excreção e retenção do nitrogênio urinário, efeito também observado na energia excretada na urina e energia digestível. No perfil de neutrófilos de machos castrados e na relação neutrófilo x linfócito de ambos os sexos houve resposta quadrática do teor dietético de lisina. Comparado ao grupo controle, constatou-se efeito positivo da segregação sanitária. O máximo desempenho de machos castrados e fêmeas dos 24 aos 50 kg, do genótipo estudado, foi obtido com 1,08% de lisina digestível, no entanto o valor médio corrigido pelo ensaio de digestibilidade e metabolismo sugere 0,910% ou 17,1 g do aminoácido por dia ou 2,72 g/Mcal de EM. Quanto à segregação sanitária, as fêmeas apresentaram maior resistência à exposição de patógenos, caracterizando menor susceptibilidade a esse tipo de estresse. / It was studied the relationship between digestible lysine and metabolizable energy in barrows and gilts diets 24 at 50 kg body weight. The design used was randomized blocks, five treatments, eight replications, an animal for experimental unit in performance assay and four replications and an animal for experimental unit in metabolism. In blood profile assay were used design completely randomized, four replications for sex and one animal for experimental unit. The treatments were 0.80, 0.90, 1.00, 1.10 and 1.20% of digestible lysine. Performance caracteristics, digestibility and metabolism and the blood profile was studied. Quadratic effect of digesltible lysine levels was observed in body weight in swine and in feed conversion in gilts. The relative body gain, crudo protein eficience and feed conversion make better linearly for barrows. There was quadratic effect of amino acid in nitrogen excretion and retention, this effect was observed too in urine excreted energy and digestible energy. In barrows neutrophil profile and in neutrophil/lymphocyte ratio for both sexes, were quadratic response by lysine dietary. Compared with control group, there was positive effect of segregation health. The maximum barrows and gilts performance from 24 to 50 kg, by studied genotype, was obtained with 1.08% lysine digestible, but the average value corrected for digestibility and metabolism suggests 0,910% or 17.1 g amino acid per day or 2.72 g/Mcal of ME. About sanitary segregation, gilts showed greater patogens resistence with less susceptibility to stress.

Foram utilizadas quatro eqüinos fêmeas, adultas, sem raça definida com peso médio de 450 ± 51.15kg. As foram compostas de partes iguais de feno da gramínea Tifton 85 (Cynodon sp) e concentrado contendo milho submetido a quatro processamentos diferentes (moído, laminado, floculado, extrusado). O experimento teve duração de 11 dias sendo oito de adaptação a dieta e 3 dias de coleta. O delineamento experimental utilizado foi quadrado latino 4x4 (tratamento x animal). O objetivo deste trabalho foi de comparar o indicador externo oxido crômico e os indicadores internos, lignina em detergente ácido (LDA), cinza insolúvel em detergente ácido (CIDA) com o método de coleta total (CT) para determinação da digestibilidade aparente da matéria orgânica (CDMO) A ponderação dos CDMO pelos indicadores foi efetuada através de um modelo o qual considerava a diferença entre o CDMO pelo indicador e pela CT aqui chamado de viés. A variância das respostas dos quatro indicadores são iguais, tendo assim a mesma precisão para estimar os CDMO. As médias das diferenças entre CT e os indicadores são diferentes de zero para cada indicador. Foi observada maior acurácia para a metodologia utilizando a lignina, em comparação aos demais indicadores testados (P<0,05), porem esta ainda se manteve distante dos resultados obtidos através da coleta total. O óxido crômico subestimou os coeficientes de digestibilidade, enquanto que a CIDA superestimou os valores. Entretanto, quanto à precisão, o indicador óxido crômico foi constatado ser o mais preciso em relação aos demais indicadores estudados (P<0,05). / Four adult mares, with no defined breed and an average weight of 450 ± 51.15kgwere used. The diets were composed of equal parts of Tifton 85 hay (Cynodon sp) and concentrate of corn submitted to four different processes (grinded, laminated, flocculated and extruded). The experiment lasted 11days, being 8 for diet adaptation and 3 for collection. The experimental design used was a Latin square 4x4 (treatment x animal). The objective of this experiment was to compare the external marker oxide chromic and the internal markers acid lignin detergent (ADL), Acid Detergent Insoluble Ash (ADIA) with the total collection method (TC) to determine the apparent digestibility of Organic Matter (OM). The consideration of OMDC by the by the markers was done through a model that took into account the difference between OMDC by the marker and the TC here called bias. The answer variation in the four markers is the same, this way demonstrating the same accuracy to estimate the OMDC. The average differences between TC and the markers are different from zero to each marker. It was observed a grater accuracy in the methodology using lignin, compared to the other markers tested( p<0,05). However, this one was still for from the results obtained through the total collection. The oxide chromic underestimated the digestibility coefficients, while ADIA overestimated the values. The marker oxide chromic was reported as being the most precise in relation to the others markers studied.

Com a utilização de quatro eqüinos fêmeas, adultas, sem raça definida, com peso médio de 450 Kg em um delineamento experimental quadrado latino 4 X 4, os objetivos deste trabalho foram determinar os coeficientes de digestibilidade total da matéria seca, matéria orgânica, nutrientes digestíveis totais, proteína bruta, fibra solúvel em detergente ácido, fibra solúvel em detergente neutro e do amido de dietas contendo milho submetido a quatro processamentos, quais sejam: trituração, laminação, floculação e, extrusão; e avaliar a resposta glicêmica, um dos indicadores do metabolismo pós-absortivo. Diferenças significativas foram encontradas na MO e FDA, sendo que a dieta que continha milho floculado teve melhor digestibilidade da MO e da FDA que a dieta contendo milho laminado e o milho triturado. O experimento também mostrou digestibilidade menor (p< 0,05) da PB da dieta com milho laminado em relação as demais. O tratamento contendo milho extrusado teve tendência uma resposta glicêmica maior. O que indica que o processamento pode ser útil na alimentação de eqüinos / Using 4 adult mares, without a defining breed, with an average weight of 450 Kg in an experimental design latin square 4 x 4, the objectives of this research were to determine the dry matter total digestibility coefficient, organic matter, total digestible nutrients, crude protein, soluble fiber in detergent acid, soluble fiber in detergent neutral and starch in diets containing corn submitted to four different processes; grinded, chopped, flocked and extrused; and evaluate the glicemic answer, one of the indicators of the of the post-absorption metabolism. Significant differences (p<0,05) were found in the MO and FDA digestibility in the diet containing flocked corn comparated to the diet with chopped corn. The experiment also demonstrated digestibility to CP smaller (p<0,05) in the treatment with chopped corn when compared to the other treataments. The diet with extrused corn had a tendency a higher glicemic answer. This demonstrates that corn processing can be useful in equine feeding.

Made available in DSpace on 2014-08-20T14:38:47Z (GMT). No. of bitstreams: 1 dissertacao_edenilse_gopinger.pdf: 812945 bytes, checksum: 757e0509d8bfb3648265884290a32bf7 (MD5) Previous issue date: 2013-02-28 / Canola meal has been studied as an alternative protein source to soybean meal in diets for non-ruminants. Therefore, this study aimed to evaluate the effects of different levels of canola meal in broiler diets on growth performance, carcass traits, digestibility, chemical composition of meat, meat quality (sensory and instrumental) and duodenal morphometry. Three hundred and twenty broilers, Cobb strain, were housed with one day old until 35 days, and were allotted to a completely randomized design with five levels of canola meal (T1 - 0%, T2 - 10%, T3 - 20%, T4 - 30% and T5 - 40%) in place of meal soybeans, and eight replicates of eight birds each. The basal diets were formulated based on corn and soybean meal, meeting the requirements of the birds. To evaluate the effect of inclusion levels of canola, except in sensory analysis, was used polynomial regression analysis. Sensory analysis was applied to analysis of variance and means were compared by Tukey test. In general the variables of weight gain and the average weight of the birds had a quadratic behavior in the different age groups and decreased with the addition of 40% canola meal. Increased levels of canola meal promoted a linear decrease in the yield of the chest at 35 days of age. The apparent digestibility of dry matter, crude protein and non-extractive nitrogen decreased linearly with increasing inclusion of canola meal. The chemical composition of the leg was not affected, but the chest was an increase in dry matter, ether extract increased and decreased moisture and ash with increasing levels of canola meal. With the inclusion of canola decreased intensity of yellow color of the meat. In sensory evaluation the only difference was found for the residual flavor of meat in 30% level of inclusion. In intestinal morphology was observed a quadratic effect unbeliever until the 20% level of inclusion of canola meal in the diet for villi height. In conclusion canola meal can be included into 20% in the diet of broilers without affecting any of the variables of interest husbandry. / O farelo de canola tem sido estudado como uma fonte proteica alternativa ao farelo de soja em dietas para não ruminantes. Com isso, este trabalho teve como objetivo avaliar os efeitos de diferentes níveis de farelo de canola nas dietas de frangos de corte sobre o desempenho zootécnico, características de carcaça, coeficiente de digestibilidade, composição centesimal da carne, qualidade da carne (instrumental e sensorial) e morfometria duodenal. Foram alojados 320 frangos machos da linhagem Cobb, com um dia de idade, até os 35 dias. As aves foram distribuídas ao acaso em um delineamento completamente casualizado, contendo cinco níveis de farelo de canola (T1 - 0%, T2 - 10%, T3 - 20%, T4 - 30% e T5 - 40%) em substituição ao farelo de soja, e oito repetições com oito aves cada uma. As dietas basais foram formuladas a base de milho e farelo de soja, atendendo as exigências nutricionais das aves. Para avaliação do efeito dos níveis de inclusão de canola com exceção na análise sensorial foi utilizada análise de regressão polinomial. Para análise sensorial foi aplicado análise de variância e as médias comparadas pelo teste de Tukey. Em geral, as variáveis de ganho de peso e o peso médio das aves tiveram um comportamento quadrático nas diferentes idades estudadas e reduziram com a inclusão de 40% de canola na dieta. O aumento nos níveis de farelo de canola promoveu uma redução linear no rendimento do peito aos 35 dias de idade. Os coeficientes de digestibilidade aparente da matéria seca, da proteína bruta e do extrativo não nitrogenado reduziram linearmente com o aumento na inclusão de farelo de canola. A composição centesimal da perna não foi afetada, porém no peito houve um aumento da matéria seca, aumento do extrato etéreo e redução da umidade e das cinzas com o aumento do nível de farelo de canola. Com a inclusão de canola houve redução na intensidade de cor amarela da carne. Na análise sensorial a única diferença encontrada foi para o sabor residual da carne no nível de 30% de inclusão. Na morfometria intestinal foi observado um efeito quadrático descrente até o nível de 20% de inclusão de farelo de canola na dieta para altura de vilosidades. Em conclusão, o farelo de canola pode ser incluído em até 20% na dieta de frangos de corte sem afetar nenhuma das variáveis de interesse zootécnico.

This body of research explores the dietary application of a bioactive, solid-state fermentation (SSF) product in contemporary and lupin-containing diets of Nile tilapia (Oreochromis niltoticus) and rainbow trout (Oncorhynchus mykiss). Consequently, the work provides holistic assessment of the influences of SSF products on animal health and performance; depending upon rearing temperature, nutritional physiologies, feed formulations and extrusion conditions; alongside information on the performance of lupins in aquafeeds. The SSF product (at 0.1 % inclusion) improved growth performance of Nile tilapia fed diets containing lupins. Phosphorous retention appeared higher when the SSF product was included in a yellow lupin (Lupinus luteus) diet whilst Mg retention was significantly higher in fish fed narrow-leaf lupin (Lupinus angustifolius). The experimental ingredients did not appear to show any clear effects upon midgut macrostructure. At an ultrastructural level, the fish fed yellow lupin alone, displayed poorest brush border characteristics but those fed yellow lupin and the SSF product showed signs of amelioration since they did not differ significantly from those fed narrow-leaf lupin. Focus was then turned towards a yellow lupin-based diet in rainbow trout, with two inclusion levels of the SSF product. The SSF product significantly improved growth performance and feed efficiency at 0.5 %, with values closer to a fishmeal-based diet than the lupin control. The SSF product increased the digestibility of protein and energy and bioavailability of numerous elements. However, the digestibility and bioavailability of certain nutrients, e.g. fibre and Zn, were only increased with a 0.5 % inclusion. The SSF product influenced vertebral Ca:P ratio but no effect on vertebral morphology was identified. Fish fed yellow lupin kernel meal displayed high Mn concentrations throughout a number of tissues. The intestinal environment was explored in depth, revealing large differences dependent upon SSF product inclusion rate. Fish fed a 0.1 % inclusion exhibited deteriorated brush border characteristics and high diversity of microbes, including increased proportions of key salmonid pathogens. Those fed a 0.5 % inclusion displayed signs of increased surface area at an ultrastructural level, reduced goblet cell numbers and a low microbial diversity; with domination of one particular family, Enterobacteriaceae. Activities of alkaline phosphatase and leucine aminopeptidase within the anterior intestine also appeared to be influenced by SSF product inclusion. Variations in haemato-immunological parameters were also observed between the treatments. In the final experiment, the SSF product was applied, pre-extrusion, to a contemporary rainbow trout formulation, at 0, 0.5, 1.0 and 1.5 %. No significant improvements to performance were identified following SSF product inclusion. However, crude protein digestibility from SSF-supplemented diets was significantly higher than the control and tendencies towards elevated retention of Ca, P, and Mg were apparent. In vitro analysis of free-phosphate release was conducted upon pre- and post-extruded diets, at varying temperatures. This indicated that neither extrusion conditions (105 °C) nor an ambient temperature of 10 °C were sufficient to cease P-liberating capabilities by the SSF product; suggesting that the two conditions combined limited the product’s efficacy in practice. This research evidenced that SSF products can be an effective means of improving the available nutrient profiles of compound diets for both omnivorous, warmwater and carnivorous, temperate finfish. Lupins are a promising alternative protein source but their nutritional value can be substantially improved by SSF product application. Exploration of the effects of SSF products on the intestinal environment revealed that both negative and positive effects on intestinal health can occur, which is highly dependent upon product inclusion rate. The holistic approaches adopted within this series of studies have seldom been performed on monogastric animals and thus provide valuable, transferable information for advancing knowledge in the application of SSF products, exogenous enzymes and lupins to farm animal feeds, in general.

Le pâturage, principal mode d’alimentation en zone tropicale, est souvent dévalorisé car il est associé à des performances animales jugées insuffisantes, et peut avoir des effets néfastes sur l’environnement. Même si l’alimentation à l’auge permet de meilleures productions, ce mode de conduite présente également des inconvénients, en termes d’investissements, de rentabilité économique, d’impact des rejets sur l’environnement et de qualité des produits. Une intensification de la conduite au pâturage semble donc une voie d’avenir, mais nécessite une meilleure connaissance de ce mode de conduite et de ses conséquences sur l’alimentation et les performances des animaux. Il apparait également nécessaire de comparer l’élevage au pâturage et à l’auge sur des critères homogènes, en dissociant les composantes de ces modes de conduite.L’objectif de la thèse est d’évaluer et de comparer la conduite au pâturage et la conduite hors sol, en tenant compte également de la distribution ou non de concentré, sur l’alimentation, la croissance, les caractéristiques d’abattage et la consommation d’eau. Dans un premier temps, nous avons étudié au cours d’une expérimentation, les effets de ces deux modes de conduite sur la croissance, les caractéristiques d’abattage et de carcasse de taurillons Créoles abattus à deux âges (précoce vs tardif). Les taurillons à l’auge avaient une croissance plus rapide, des poids de carcasse plus élevés, ainsi que des carcasses plus grasses. Nous avons observé qu’abattre plus tardivement au pâturage (17 et 21 mois vs 14 et 17 mois à l’auge), permettait d’atteindre des poids finaux similaires à ceux obtenus à l’auge et des carcasses de meilleure qualité, plus riche en muscle. Nous avons expliqué la majorité de nos résultats par les effets combinés des modes de conduite et de l’alimentation et avons voulu étudier leurs effets respectifs. Dans un second temps, l’étude des effets du mode de conduite a été faite dans un premier temps, par le biais d’une méta-analyse. Les performances des animaux à l’auge étaient meilleures qu’au pâturage, mais ces effets dépendaient de la stratégie de complémentation. De cette méta-analyse est également apparu le manque d’études auge vs pâturage sur l’alimentation et à ration égale. Afin d’étudier les effets respectifs du mode de conduite et de la stratégie de complémentation, un dispositif analytique avec des taurillons élevés à l’auge et au pâturage complémentés ou non avec du concentré a été mis en place. Dans un premier temps, une étude méthodologique menée grâce à ce dispositif nous a permis d’identifier que la SPIR permettait la meilleure estimation de la dMO, l’OMI et la MODI au pâturage. Les résultats de l’étude analytique ont montré que les animaux au pâturage utilisaient mieux leur alimentation pour leur croît que ceux à l’auge et la stratégie de complémentation influençait davantage ces variables que le mode de conduite. Avec une stratégie de complémentation appropriée, les animaux au pâturage peuvent atteindre des performances similaires à celles obtenues à l’auge. / Grazing, main way of feeding ruminants in the tropics, is often undervalued because it is associated with animal performance deemed insufficient, and may have adverse effects on the environment. Even if stall feeding allows better production, this way of feeding has drawbacks in terms of investment, profitability, impact of emissions on the environment and product quality. Intensification of grazing seems a way forward, but requires a better understanding of this way of feeding and its impact on feeding and animal performance. It also appears necessary to compare grazing and stalls feeding on homogeneous criteria, separating the components of these modes of management.The aim of the thesis is to evaluate and compare stalls and pasture feeding environment, taking into account also the distribution or not of concentrate on feeding, growth, slaughter characteristics and water consumption. At first , we studied in an experiment , the effects of these two feeding systems on growth, slaughter and carcass characteristics of Creoles bulls slaughtered at two ages (early vs. late ). Bulls fed in trough grew faster, had greater carcass weight and fatter carcasses. We observed that a later slaughter of grazing animals (17 and 21 months vs. 14 and 17 months in stalls), allowed to reach final weights similar to those obtained in stalls and carcasses richer in muscle. We explained most of our results by the combined effects of feeding environment and complementation strategy and wanted to study their effects. In a second step, the study of the effects of feeding environment was made in first instance, through a meta-analysis. Stalls fed animals had greater performances than pasture fed ones, but these effects depended on complementation strategy. This meta-analysis also highlighted the lack of knowledge on intake and digestibility at pasture, which is a limitation on attempts to compare with measurements carried out in trough-fed animals. To investigate the relative effects of feeding environment and complementation strategy, we conceived an analytical trial with Creole bulls reared in stalls and at pasture, supplemented or not with concentrate. First of all, this analytical trial was the support of a methodological study, which identified that the NIRS method allows the best estimate of the OMD, OMI and DOMI at pasture. The analytical trial showed that grazing animals had better feed efficiency feed for their growth than stall fed ones and complementation strategy influenced more these variables than feeding environment. With an appropriate strategy for complementation, grazing animals can achieve similar performance to those obtained at the trough.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / An in vivo digestibility experiment was conducted to evaluate the influence of degradable nitrogen source and feeding frequency on the digestion process and utilization of kikuio grass hay. Eight castrated male lamb (35 ± 4 Kg live weight) maintained in individual metabolic cage, were used in a 2x2 factorial experiment according to a replicated 4x4 Latin Square design. Treatments tested were the combination of two supplement feeding frequencies: once (morning) or twice (morning and aftermoon) daily, and two supplements, based on cassava meal plus calcium caseinate or cassava meal plus urea. For all treatments kikuio hay was fed ad. Libitum and the supplements were fed at a rate of 7 g/Kg live weight daily. Animals supplemented twice day consumed higher quantity of the gross fractions, either in absolute values or in proportion to live weight or metabolic weight (P<0,05) and they tended to consume higher quantity of digestible energy and to synthesize more microbial protein (P<0,10). Feeding frequency did not influence the digestibility. When calcium caseinate was fed animal tended (P<0,10) to have higher dry matter intake in relation to live weight and higher organic matter intake in relation to metabolic weight. There was interaction between nitrogen source × frequency of supplementation on intake of both digestible organic matter and digestible energy. Animals receiving supplement with calcium caseinate twice a day and supplemented with urea once a day have higher intake of theses fractions. Animals supplemented once a day presented higher rumen sugar concentration (P<0,05), but pH as well as ammonia and peptides + aminoacid concentration were not affected by supplementation frequencys. Higher concentrations of NH3 and lower concentrations of pep+aa were observed in animals supplemented with urea (P<0,05). The supplement feeding frequency did not influence the digestion process and forage utilization when the nitrogen source was urea, but when the nitrogen source was calcium caseinate, supplementation twice daily improves intake and nutrients offer to the animals. / Para avaliar se as freqüências de oferta de suplemento, com diferentes tipos de nitrogênio degradável, influenciam os processos de digestão e a utilização do feno de uma gramínea tropical, foi realizado um estudo de digestibilidade in vivo, utilizando oito ovinos machos castrados (PV médio 35 ± 4 Kg), mantidos em gaiolas de metabolismo individuais em um delineamento duplo quadrado latino 4x4 em um esquema fatorial 2x2. Como volumoso foi utilizado feno de capim quicuio (Pennisetum clandestinum) com 70 dias de rebrota, como suplemento foi utilizada uma mistura a base de farinha de mandioca mais uréia ou caseinato de cálcio, além de uma mistura de sal mineral comercial e melaço em pó. Os tratamentos foram duas freqüências de suplementação × duas fontes de nitrogênio. As combinações foram suplementação com farinha de mandioca mais caseinato fornecido uma vez ao dia (manhã) e duas vezes ao dia (manhã e tarde) e suplementação com farinha de mandioca mais uréia uma vez ao dia (manhã) e duas vezes ao dia (manhã e tarde) à nível de 7 g/Kg de PV. O volumoso foi fornecido Ad. Libitum duas vezes ao dia (manhã e tarde). Os animais quando suplementados duas vezes ao dia consumiram maior quantidade das frações brutas, tanto em valores absolutos, como em proporção ao PV ou peso metabólico (P<0,05) e tenderam a consumir maior quantidade de energia digestível e a sintetizar mais proteína microbiana (P<0,10). A freqüência de suplementação não influenciou na digestibilidade e a eficiência da síntese de proteína microbiana. Somente houve uma tendência de quando os animais foram suplementados com caseinato consumirem maior quantidade de matéria seca em relação ao peso vivo e matéria orgânica em g/Kg de peso metabólico (P<0,10), não havendo mais nenhum efeito da suplementação com diferentes fontes de nitrogênio degradável no rúmen. Houve interação fonte de nitrogênio × freqüência de suplementação no consumo de matéria orgânica digestível e energia digestível onde os animais quando recebendo suplemento com caseinato duas vezes ao dia e quando suplementados com uréia uma vez ao dia consumiram mais destas frações. Quando os animais foram suplementados uma vez por dia apresentaram maiores concentrações ruminais de açucares (CHO) (P<0,05), e o pH, amônia (NH3) e peptídeos + aminoácidos (pep+aa) não foram influenciados pelas diferentes freqüências de suplementação. Maiores concentrações ruminais de NH3 e menores de pep+aa foram observadas quando os animais foram suplementados com uréia (P<0,05). A suplementação com farinha de mandioca mais caseinato fornecido duas vezes ao dia manifestou ser superior as demais suplementações, no entanto os mecanismos não ficaram bem estabelecidos, necessitando estudos adicionais.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of the study is to evaluate the effect of Acacia mearnsii tannin extract on balance of nutrients and efficiency of energy of steers. The experiment was conducted in a Latin Square design, with eight Holstein steers (338 ± 32,2 kg body weight (BW)). The animals have been housed in metabolism cages, fed on a diet composed by 90% corn silage and 10% concentrate at two levels of intake with or without the inclusion of Acacia mearnsii tannin extract. The treatment structure was a 2 × 2 factorial; intake, 1.2 versus 1.8 × NEm and tannin addition vs. control. The experiment was conducted in four periods of 21 days, of which the first 14 days were intended for the adaptation of the animals to the diets and the last 7 days to evaluate whole body energy balance and endogenous heat production. For measurement of heat production and nutrient balance, expired respiratory gases, urine, and feces were collected. Fecal and urine collections were taken during 7 days. Whole-body heat production (HP) was calculated by indirect calorimetry from O2 consumption and CO2 production and corrected for CH4 production and urinary N excretion using the equation proposed by Brouwer (1965). The inclusion of tannin extract had no effect on energy and nitrogen balance. The two levels of intake had effect on energy retention and whole-body heat production (P<0.001). / Este estudo foi conduzido com o objetivo de avaliar a inclusão de extrato tanífero de Acacia mearnsii a dois níveis de consumo da dieta total de bovinos sobre o balanço de nutrientes e eficiência da utilização de energia. Foram utilizados oito bovinos machos, castrados, da raça Holandês (338 ± 32,2 kg de peso corporal (PC), aleatoriamente alocados em um Quadrado Latino replicado em esquema fatorial 2 x 2 (com ou sem a inclusão de extrato tanífero x níveis de consumo). A dieta experimental foi composta de silagem de milho, milho moído e premix mineral, a relação volumoso:concentrado utilizada foi de 90:10. Foram ofertados dois níveis de consumo: 1,5 e 1,8 × Energia Líquida de mantença (Elm). O experimento foi constituído de quatro períodos de 21 dias cada, sendo 14 dias de adaptação às dietas e 7 dias de coleta de amostras. Coletas fecais e urinárias foram realizadas durante os 7 dias de coleta. A produção de calor foi calculada pela calorimetria indireta a partir do consumo de O2 e a produção de CO2 corrigido para a produção de CH4 e excreção de nitrogênio urinário utilizando equação proposta por Brouwer (1965). A inclusão do extrato tanífero não teve efeito sobre o balanço de energia e nitrogênio. Os níveis de ingestão influenciaram a retenção de energia e a produção de calor (P<0,001).

Ensiling is one of the most common processes used as a conservation method for forages on farms and plays an important role in farm economics. Therefore, with the aim to improve the conservation and the nutritive value of silage, the utilization of silage additives such as fibrolytic enzymes (FE) and lactic acid bacteria (LAB) inoculants has been a common on-farm practice. FE are enzymes capable of breaking down complex polysaccharides such as cellulose and hemicellulose. The latter results in an increased substrate availability for epiphytic and inoculated LAB during silage fermentation, thus promoting a higher production of organic acids such as lactic acid and volatile fatty acids such as acetic acid, which are key acids to improve the conservation of the forage by reducing dry matter losses and improving aerobic stability. The degradation of cellulose and hemicellulose results in a partial degradation of fiber measured by the neutral detergent fiber (NDF) and acid detergent fiber (ADF) extraction technique. Therefore, FE could have the potential to improve ruminal fiber digestibility of treated forages. Alternatively, LAB inoculants are used as silage additives with the primary objective to dominate over the epiphytic bacteria present in silage, to accelerate the fermentation process, and to reinforce aerobic stability of the forage at feed out. Additionally, recent research has shown that certain strains of LAB might have the potential to partially degrade NDF and ADF during ensiling, therefore improving fiber digestibility. The first objective of this research project was to evaluate the effects of different mixtures of FE (a mixture of cellulase and xylanase (C+X); xylanase (X); ß-glucanase (G); a mixture of ß-glucanase and xylanase (G+X); and a negative control) on alfalfa harvested at early and late maturity, and stored for 40 or 120 d of ensiling. Alfalfa harvested at early maturity, treated with FE and ensiled for 40 d did not show significant improvements during ensiling in fiber degradability, fermentation characteristics or fiber digestibility in vitro assessed by the Tilley and Terry methodology. However, when harvested at late maturity and treated with a mixture of C+X; X and G+X, the NDF and ADF content at 40 d of ensiling tended to decrease. FE improved total volatile fatty acid production at 40 and 120 d of ensiling. Improvements in fiber digestibility were observed in vitro at 24 h for the C+X treatments. The results of this study suggest that the effects of FE are more pronounced in silages higher in fiber concentration, such as in the late-maturity alfalfa cut. The second objective of this research was to evaluate the effects of two homofermentative LAB (hoLAB) strains, and two heterofermentative LAB (htLAB) strains on alfalfa harvested at late maturity and stored for 40 or 120 d of ensiling. At 40 d of ensiling, hoLAB-treated silages had the greatest DM recovery and the lowest ADF concentration. Lactic acid production was greater for hoLAB-treated silages. At 120 d of ensiling, hoLAB-treated silages had the highest concentration in lactic acid whereas htLAB had the highest concentration in acetic acid and hoLAB-treated silages had the lowest ADF and NDF concentrations while htLAB tended to have higher NDF concentrations. Overall, it appears that the fiber degradation promoted during ensiling influenced digestibility depending upon hoLAB or htLAB inoculation, with hoLAB showing improved digestibility levels. The presented work suggests that certain FE can have the potential as a management resource on farms aiming to improve the nutritive value of forages with a high fiber concentration. As expected, hoLAB and htLAB inoculants improved the fermentation characteristics of alfalfa silage, but it was shown that LAB may exert a differential effect on fiber digestibility depending on their specific metabolism.

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.