Search

The objectives of this study were: 1) to compare the effects of live yeast (LY), yeast fermentation product (YFP), a mix of Lactobacillus acidophilus and Propionibacterium freudenreichii (MLP), and Lactobacillus plantarum included as additives in dairy cows’ diets on in vitro ruminal fermentation and gas production (GP); and 2) to evaluate the effects of L. plantarum as direct-fed microbials (DFM) in dairy cows’ diets on in vitro ruminal fermentation, GP, nutrient digestibility, and N metabolism. Three experiments were carried out: Exp. 1 had the objective to compare all additives regarding ruminal fermentation parameters: an Ankom GP system was used in a completely randomized design, consisting of four 48 h incubations, and eight replications per treatment. There were eight treatments: a basal diet without additive (CTRL) or with one of the following additives: LY, YFP, MLP, or L. plantarum at four levels (% of diet Dry Matter (DM)): 0.05% (L1), 0.10% (L2), 0.15% (L3), and 0.20% (L4). In Exp. 2, a batch culture was used to evaluate ruminal fermentation, and CO2 and CH4 production using the same treatments and a similar experimental design, except for having 16 replications per treatment. Based on Exp. 1 and 2 results, Exp. 3 aimed at evaluating the effects of the L. plantarum on ruminal true nutrient digestibility and N utilization in order to evaluate the use of L. plantarum as DFM. The treatments CTRL, MLP, L1, and L2 were used in a replicated 4 × 4 Latin square design using a dual-flow continuous culture system. Data were analyzed using linear and nonlinear regression; treatment means were compared through contrasts, and L treatments in Exp. 1 and 2 were tested for linear, quadratic, and cubic effects. In Exp. 1, all treatments containing additives tended to reduce OM digestibility as well as reduced total volatile fatty acids (VFA) concentration and total GP. The YFP had greater OM digestibility than LY, and MLP treatment had greater total VFA concentration compared to L. plantarum treatments. In Exp. 2, additives reduced CO2 production, and there were no major differences in CH4. In Exp. 3, all additives reduced NH3-N concentration. In conclusion, pH and lactate concentration were not affected in all three experiments regardless of additive tested, suggesting that these additives may not improve ruminal fermentation by pH modulation; and L. plantarum may improve ruminal N metabolism when used as DFM in high-producing dairy cows’ diets, mainly by reducing NH3-N concentration.

The objective of this study was to determine the chemical composition and apparent metabolizable energy (AME), AME corrected for nitrogen balance (AMEn) and its respective metabolizable coefficients of animal byproducts for broiler chickens with different ages. Meat and bone meal, poultry by-product meal, tilapia processing residue and poultry fat were evaluated. A total of 760 male broiler chickens were used and evaluated and the phases: pre-starter (1 to 8 d of age); starter (11 to18 d); grower 1 (21 to 28 d); grower 2 (31 to 38 d), and finisher (41 to 48 d). Total excreta collection method was performed in five metabolism assays. The experimental design was completely randomized, and data were submitted to analysis of variance, posteriorly, the four feeds were compared by Tukey test and a regression analysis was performed with broiler chickens age. The significance was considered at 5% probability. The values of AME and AMEn were higher in older birds for all ingredients. The lesser CAME and CAMEn were obtained for meat and bone meal, for the regression analysis poultry by-product meal, tilapia processing residue and poultry fat had an increased linear effect with birds age and there was no adjust for meat and bone meal for regression analysis. El objetivo de este estudio fue determinar la composición química y energía metabolizable aparente (EMA), EMA corregido para el balance de nitrógeno (EMAn) y sus coeficientes de energía metabolizable de subproductos de origen animal en pollos de engorde de diferentes edades. Los cuatro alimentos evaluados fueron harina de carne y huesos, harina de vísceras, harina del residuo del procesamiento de tilapia y grasa de ave. Se utilizaron y evaluaron un total de 760 pollos de engorde machos en las fases: preinicial (1 a 8 días de edad), crecimiento 1 (21 a 28 días); crecimiento 2 (31 a 38 días) y terminación (41 a 48 días). El método de recolección total de heces se llevó a cabo en cinco ensayos de metabolismo. El diseño experimental fue completamente aleatório, los datos fueron sometidos a análisis de varianza y los cuatro alimentos se compararon mediante la prueba de Tukey, también se realizó un análisis de regresión para la edad de las aves, la significancia se consideró al 5% de probabilidad. Los valores de EMA y EMAn fueron mayores en aves con edades más avanzadas para todos los ingredientes y los coeficientes de metabolizabilidad más bajos ocurrieron en la harina de carne y huesos. En el análisis de regresión, los valores energéticos de la harina de vísceras, harina de residuos de procesamiento de tilapia y grasa de ave mostró un aumento lineal con la edad de las aves y no hubo ajuste para la harina de carne y huesos. O objetivo deste estudo foi determinar a composição química e energia metabolizável aparente (EMA), EMA corrigida para o balanço de nitrogênio (EMAn) e respectivos coeficientes de energia metabolizável de subprodutos de origem animal em frangos de corte de diferentes idades. Os quatro alimentos avaliados foram: farinha de carne e ossos, farinha de vísceras, farinha do resíduo do processamento da tilápia e gordura de aves. Um total de 760 frangos de corte machos foram utilizados e avaliados nas fases: pré-inicial (1 a 8 dias de idade), crescimento 1 (21 a 28 dias); crescimento 2 (31 a 38 dias) e terminação (41 a 48 dias). Foi realizado o método de coleta total em cinco ensaios de metabolismo. O delineamento experimental foi inteiramente casualizado e os dados foram submetidos à análise de variância e as médias dos quatro alimentos foram comparados pelo teste de Tukey, também foi realizada análise de regressão para a idade das aves, a significância foi considerada a 5% de probabilidade. Os valores de EMA e EMAn foram maiores nas aves com idades mais avançadas para todos os ingredientes e os menores coeficientes de metabolizabilidade ocorreram na farinha de carne e ossos. Na análise de regressão os valores energéticos da farinha de vísceras, farinha do resíduo do processamento de tilápia, e gordura de aves apresentaram um aumento linear com a idade das aves e não ocorreu ajuste para a farinha de carne e ossos.

The objective of this study was to evaluate the effect of inclusion of condensed tannins (CT) from black wattle (Acacia mearnsii) on feed intake, ruminal protozoa population, ruminal fermentation, and nutrient digestibility in Jersey steers. Five ruminally-cannulated steers were used in a 5x5 Latin square design, with five periods of 20 days each (14 days for diet adaptation and six days for sample collection per period). Treatments were composed of dietary inclusion levels of condensed tannins at 0, 5, 10, 15, and 20 g/kg of diet dry matter. Intakes of dry matter, organic matter, ether extract, crude protein, neutral detergent fiber, and total digestible nutrients were not affected by condensed tannins. The ruminal pH was reduced linearly with tannin levels. Ruminal ammonia nitrogen concentration was not affected by tannins. Tannins reduced the molar proportion of acetate and did not affect the ruminal protozoal population, which might be related to the low doses used. Digestibilities of dry matter, organic matter, and neutral detergent fiber were not altered, however, there was a linear reduction in crude protein digestibility. Based on these results, CT extracts from black wattle are not recommended for improving nutrient utilization in steers at the tested levels.

The objective of this study was to evaluate the use of a combination of essential oils, prebiotics and antibiotics on broiler production. The treatments consisted of a normal diet meeting the nutritional requirements, and diets with a 5% reduction of nutritional requirements, supplemented or not with antibiotics (En+Sal) (10 g ton-1 enramycin and 125 g ton-1 salinomycin) or a blend of essential oils (EOFOS) (oregano, anise and lemon) plus fructooligosaccharides (125 g ton-1). A total of 1,152 male one-day-old broilers were randomized by weight and distributed into a 2*3 factorial design, consisting of six treatments with each treatment containing eight replicates of 24 birds per experimental unit. The Student-Newman-Keuls test was performed at 5% probability. Broiler performance was evaluated at 10, 21 and 42 days, intestinal morphometry was evaluated at 21 days, microbiological cecum counts at 33 days, blood parameters at 35 days and carcass and cuts yield at 42 days of age. Broilers fed reduced diets had a reduction in performance (P < 0.05). There was an interaction (P < 0.05) between diet type and prebiotics for jejunum villus height and villus height:crypt depth ratios for all intestinal segments. There was no effect (P > 0.05) of growth promoters and diet type on the Lactobacillus and Bifidobacterium populations within the gastrointestinal tract. There were no differences for duodenum or ileum villus heights (P > 0.05). Broilers fed EOFOS showed higher villus height in the jejunum at 21 days. There were no effects on blood parameters of different diets and growth promoters (P > 0.05), nor on carcass and cuts yield, abdominal fat and relative liver weight (P > 0.05). Broilers receiving the normal diet with EOFOS showed higher villus height in the jejunum at 21 days when compared to the normal diet with antibiotics and the normal diet without growth promoters. However, there were no effects of growth promoters and diet type on broiler performance at 42 days. O objetivo com este estudo foi avaliar o uso de uma combinação de óleos essenciais, prebióticos e antibióticos na produção de frangos de corte. Os tratamentos consistiram em uma dieta normal que atende as exigências nutricionais e uma dieta com redução de 5% das exigências nutricionais suplementada ou não com antibióticos (En+Sal) (10 g ton-1 enramicina e 125 g ton-1 salinomicina) ou um blend de óleos essenciais (EOFOS) (orégano, anis e limão) + frutooligossacarídeos (125 g ton-1). Um total de 1.152 frangos machos de um dia de idade foram casualizados no peso e distribuídos em um arranjo fatorial 2*3, consistindo em seis tratamentos com cada tratamento contendo oito repetições de 24 aves por unidade experimental. Os dados foram analisados pelo SAS - Versão 9.1, o teste Student Newman Keuls foi realizado a 5% de probabilidade. Aos 10, 21 e 42 dias, avaliou-se o desempenho dos frangos, a morfometria intestinal aos 21 dias, contagem microbiológica de ceco aos 33 dias, parâmetros sanguíneos aos 35 dias e rendimento de carcaça e cortes aos 42 dias de idade. Os frangos alimentados com dietas com redução nas exigências apresentaram uma redução no desempenho (P < 0.05). Ocorreu interação (P < 0.05) entre tipo de dieta e promotores de crescimento para a altura de vilo no jejuno e para a relação vilo:cripta em todos os segmentos intestinais. Não ocorreu efeito dos promotores de crescimento e tipo de dieta na população de Lactobacillus e Bifidobactérias do trato gastrointestinal. Não ocorreu diferença na altura de vilos no duodeno (P > 0.05). Aves alimentadas com EOFOS demonstraram maior altura de vilos no jejuno aos 21 dias. Não houve efeitos nos parâmetros sanguíneos de diferentes dietas e promotores de crescimento (P > 0.05), nem no rendimento de carcaça e cortes, gordura abdominal e peso relativo do fígado (P > 0.05). Frangos de corte que receberam dieta normal com EOFOS apresentaram maior altura das vilosidades no jejuno aos 21 dias quando comparados à dieta normal com antibióticos e à dieta normal sem promotores de crescimento. Entretanto, não houve efeito dos promotores de crescimento e tipo de dieta no desempenho dos frangos aos 42 dias.

The objective of this study was to evaluate the effects of five levels of condensed tannins (CT) from black wattle (Acacia mearnsii) in the diets of lactating dairy cows on intake, nutrient digestibility, ruminal microbial protein synthesis, milk production, composition, oxidative profile, and blood metabolites. Five Holstein cows (88 &plusmn, 26.8 days in milk) were allocated in a 5 x 5 Latin square design for a period of 20 days (14 days of diet adaptation and six for sampling). Treatments were the inclusion levels of CT at 0, 5, 10, 15 and 20 g/kg of dry matter (DM) in the diet. There was no effect of CT on DM intake. The digestibility of DM and neutral detergent fiber changed quadratically, with the maximum values at 12.2 and 11.4 g/kg of DM, respectively. There was no effect on ruminal microbial protein synthesis and milk production, however, milk casein concentration was reduced linearly. There was no effect on the milk oxidative profile. Inclusion of CT at levels up to 20 g/kg of DM did not affect intake or microbial protein synthesis, however, added CT depressed the production of energy corrected milk and milk casein concentration.

The objective of this study was to determine the optimal level of dried brewers' grains (DBG) to replace soybean meal in diets for lactating Holstein cows. Five cows, around 88±28 days in milk, were distributed in a 5 × 5 Latin square design and fed diets containing different levels of DBG (0, 25, 50, 75, and 100%). The forage:concentrate ratio of the diet was 50:50. Feed intake, dry matter, nutrient digestibility, microbial synthesis, milk production and composition, and the economic viability of the diets were evaluated. There was reduction in dry matter intake and, consequently, in crude protein and non-fiber carbohydrates with increased levels of DBG. This occurred due to physical limitation of rumen caused by increased neutral detergent fiber intake. Ether extract intake also increased with levels of DBG due to higher concentrations of this nutrient in the diet. Apparent dry matter, organic matter, ether extract, and neutral detergent fiber digestibility increased with replacement of soybean meal by DBG. Milk production showed a quadratic effect and the levels of fat, protein, and total solids reduced linearly. Each 1% of soybean meal replaced by DBG in concentrate led to a reduction of 0.04, 0.02, and 0.06 g kg-1 of milk fat, protein, and total solids, respectively. The milk production efficiency increased linearly and the microbial synthesis efficiency was not affected. The economic return increased along with the DBG levels. Thus, DBG levels replacing up to 75% of soybean meal can be used to feed lactating cows, since it provides improvements in digestibility, milk production efficiency, and economic return without affecting microbial efficiency.