RESUMO
Since their discovery, rumen ciliates of domestic cattle have been reported from various geographic locations. However, until now there is only one taxonomic inventory of ciliates associated with Brazilian cattle. The present study aimed to assess the community composition, relative abundance, richness, and density of rumen ciliates in Brazilian cattle, whose feeding diets were supplemented with crescent urea levels. Across all treatments analyzed, one subclass, two orders, three families, 11 genera, and 31 species of ciliates were identified. The ciliate community composition and species richness varied among the four treatments used. However, the total ciliate density was not affected by the experimental diets. We described a new entodiniid morphotype, Entodinium caudatum m. orbonuclearis, and recorded Oligoisotricha bubali for the second time in Brazil.
Assuntos
Cilióforos , Rúmen , Humanos , Bovinos , Animais , Brasil , Dieta/veterinária , UreiaRESUMO
Protozoa population, microbial synthesis efficiency and rumen degradability of dry matter and neutral detergent fiber in cattle fed on diets with different lipid rates were evaluated. Nine 16-month-old Nelore young bulls, cannulated in the rumen and duodenum, weighing 232 ± 35 kg, were used in the trial. Experimental design consisted of a 3 x 3 square in triplicate, comprising the following treatments: 2, 4 and 6% lipid in diet. In situ degradability was assessed by rumen incubation of corn silage, soybean, soybean meal and citrus pulp during 0, 3, 6, 12, 24, 48, 72 and 96h. The flow of microbial nitrogen and microbial efficiency were not influenced (p > 0.05) by the inclusion of lipid levels in the diet. When the animals received diet with 4% lipid, there was a reduction (p 0.05) in the potential and effective degradation of dry matter of corn silage (64.10 and 55.04%, respectively), soybean meal (94.55 and 60.83%, respectively) and soybeans (98.45 and 76.44%, respectively). Since the degradability of neutral detergent fiber was not affected, 4 and 6% lipid levels in the diet may be used without altering the parameters of rumen degradation of fiber.
RESUMO
Protozoa population, microbial synthesis efficiency and rumen degradability of dry matter and neutral detergent fiber in cattle fed on diets with different lipid rates were evaluated. Nine 16-month-old Nelore young bulls, cannulated in the rumen and duodenum, weighing 232 ± 35 kg, were used in the trial. Experimental design consisted of a 3 x 3 square in triplicate, comprising the following treatments: 2, 4 and 6% lipid in diet. In situ degradability was assessed by rumen incubation of corn silage, soybean, soybean meal and citrus pulp during 0, 3, 6, 12, 24, 48, 72 and 96h. The flow of microbial nitrogen and microbial efficiency were not influenced (p > 0.05) by the inclusion of lipid levels in the diet. When the animals received diet with 4% lipid, there was a reduction (p 0.05) in the potential and effective degradation of dry matter of corn silage (64.10 and 55.04%, respectively), soybean meal (94.55 and 60.83%, respectively) and soybeans (98.45 and 76.44%, respectively). Since the degradability of neutral detergent fiber was not affected, 4 and 6% lipid levels in the diet may be used without altering the parameters of rumen degradation of fiber.
RESUMO
Animal simulation models are sets of equations used to describe biological processes. A non-steady state simulation model of cattle digestion is presented in order to represent nutrient availability as a response to feed intake pattern and the kinetics of particle size reduction. Variables representing the particle size reduction and discontinuous voluntary feed intake were included in a mechanistic model created to optimize the supplementation of sugarcane based diets. In general the predicted values were very close to observed values for fibre and nitrogen flows. The model has not shown consistent bias in relation to the behavior of the observed data of duodenal flow of neutral detergent fiber and non-ammonia nitrogen. Milk production simulations were quite close to actual values. Predictions were improved by the non steady-state model, taking into account variable intake rate in relation to the previous steady-state model. The model can be used to select strategies for supplementation of cattle fed sugarcane based diets.
Modelos de simulação animal são conjuntos de equações utilizados para descrever processos biológicos. Um modelo de simulação da digestão de bovinos em condições de ingestão descontínua é apresentado com objetivo de representar a disponibilidade de nutrientes como resposta ao padrão de consumo de alimentos e à cinética da redução do tamanho de partícula. Variáveis representando a redução do tamanho de partículas e consumo de alimento descontinuo foram incluídas em um modelo mecanicista criado para aperfeiçoar a suplementação de dietas à base de cana-de-açúcar. Os valores estimados estiveram muito próximos dos valores observados para fluxos de fibra e nitrogênio. O modelo não apresentou desvios consistentes dos valores observados de fluxo duodenal de fibra em detergente neutro e nitrogênio não-amoniacal. A média geral das produções de leite foi estimada com precisão. As estimativas sob condições de disponibilidade variável de nutrientes apresentaram maior precisão quando comparadas com o modelo anterior que assumia consumo continuo de nutrientes. O modelo pode ser usado para selecionar estratégias de suplementação de dietas à base de cana-de-açúcar em vacas em lactação.
RESUMO
Animal simulation models are sets of equations used to describe biological processes. A non-steady state simulation model of cattle digestion is presented in order to represent nutrient availability as a response to feed intake pattern and the kinetics of particle size reduction. Variables representing the particle size reduction and discontinuous voluntary feed intake were included in a mechanistic model created to optimize the supplementation of sugarcane based diets. In general the predicted values were very close to observed values for fibre and nitrogen flows. The model has not shown consistent bias in relation to the behavior of the observed data of duodenal flow of neutral detergent fiber and non-ammonia nitrogen. Milk production simulations were quite close to actual values. Predictions were improved by the non steady-state model, taking into account variable intake rate in relation to the previous steady-state model. The model can be used to select strategies for supplementation of cattle fed sugarcane based diets.
Modelos de simulação animal são conjuntos de equações utilizados para descrever processos biológicos. Um modelo de simulação da digestão de bovinos em condições de ingestão descontínua é apresentado com objetivo de representar a disponibilidade de nutrientes como resposta ao padrão de consumo de alimentos e à cinética da redução do tamanho de partícula. Variáveis representando a redução do tamanho de partículas e consumo de alimento descontinuo foram incluídas em um modelo mecanicista criado para aperfeiçoar a suplementação de dietas à base de cana-de-açúcar. Os valores estimados estiveram muito próximos dos valores observados para fluxos de fibra e nitrogênio. O modelo não apresentou desvios consistentes dos valores observados de fluxo duodenal de fibra em detergente neutro e nitrogênio não-amoniacal. A média geral das produções de leite foi estimada com precisão. As estimativas sob condições de disponibilidade variável de nutrientes apresentaram maior precisão quando comparadas com o modelo anterior que assumia consumo continuo de nutrientes. O modelo pode ser usado para selecionar estratégias de suplementação de dietas à base de cana-de-açúcar em vacas em lactação.