AVALIAÇÃO DE SISTEMAS ENERGÉTICOS PARA VACAS LEITEIRAS

Objetivou-se avaliar a qualidade da predição das exigências de energia para vacas leiteiras do sistema de Oliveira (2015) para condições tropicais, em comparação aos sistemas AFRC (1993), NRC (2001), Feed into Milk (THOMAS, 2004), INRA (2007), CSIRO (2007) e Moraes et al. (2015). Utilizou-se observações de quatro experimentos de alimentação de vacas leiteiras do tipo rotativo, totalizando 181 observações de consumo de nutrientes digestíveis totais (NDT) de 16 dietas experimentais. O conjunto de dados construídos apresentou uma ampla variação nas características dos animais (produção de leite entre 6,1 a 36,5 kg/dia), dieta e consumo de NDT (4,0 a 16,6 kg/dia). O sistema energético de Oliveira (2015) explicou 83% do consumo de NDT observado, superestimou o consumo de NDT em média 0,35 kg/dia e apresentou raiz quadrada do erro médio de predição (RQEMP) de 12,2% do valor observado. Os sistemas AFRC (1993), NRC (2001), Feed into Milk (THOMAS, 2014) e Moraes et al (2015) apresentaram RQEMP similares (P > 0,05) ao sistema de Oliveira (2015), indicando similaridade na acurácia para predizer as exigências de energia para vacas leiteiras em condições tropicais. Recomenda-se ainda investigar a adequação destes sistemas energéticos em experimentos de longa duração.Palavras-chave: acurácia; energia; sistemas nutricionais. EVALUATION OF ENERGETICS SYSTEMS FOR DAIRY COWS ABSTRACT: The objective was evaluate accuracy and precision of the estimated energy requirements for lactating dairy of the Oliveira (2015) system to tropical condition, compared to AFRC (1993), NRC (2001), Feed into Milk (THOMAS, 2004), INRA (2007), CSIRO (2007) and proposed by Moraes et al. (2015). Four rotative feeding trials were used as dataset, totalizing 181 observations of total digestible nutrient (TDN) intake from 16 diets. Dataset had wide variation in animal performance (milk yield between 6.1 to 36.5 kg/day), diet and TDN intake (4.0 to 16.6 kg/day). The Oliveira (2015) system explained 83% of the observed TDN intake, over-predicted TDN intake by 0.34 kg/day and presented root mean square error of prediction (RMSPE) of the 12.2% of the observed TDN intake. AFRC (1993), NRC (2001), Feed into Milk (THOMAS, 2014) e Moraes et al (2015) systems had similar RMSPE (P > 0.05) to Oliveira (2015) system, indicating similar accuracy to predict energy requirement for dairy cows under tropical conditions. We recommended to investigate the adequacy these systems in long term feeding trials.Keywords: accuracy; energy; nutritional systems

MANEJO ECOFISIOLÓGICO DO PASTO NA PRODUÇÃO DE OVINOS

Objetivou-se com esta revisão de literatura apresentar alguns resultados de pesquisa, por meio de trabalhos que buscaram consolidar a melhor forma de manejo das pastagens e do pastejo. Buscou-se aliar estudos já existentes na área, para comparar com os resultados obtidos com as novas técnicas. Nas pesquisas são utilizadas os sitemas de pastejo sob lotação continua e sob lotação rotativa, com o âmbito de equilibrar o manejo com a fisiologia da planta. Conclui-se com os resultados de pesquisas que cada cultivar deve ter seu própio manejo, pois reagem de forma diferente após a desfolhação. Porém, sem um manejo adequado da estrutura do pasto, nem o animal e nem a planta poderão exercer seu máximo potencial produtivo. Neste sentido, estudos devem ser realizados para que possamos entender e aliar o manejo do pastejo com o manejo da pastagem, maximizando o sistema de produção.

ESTRATÉGIAS NUTRICIONAIS PARA AUMENTAR AS PROPRIEDADES NUTRACÊUTICAS DO LEITE: CONCENTRAÇÕES DE ENTEROLACTONA E ÁCIDO LINOLEICO CONJUGADO

This study aimed to describe nutritional strategies to increase milk nutraceutical properties, including mainly strategies to increase the concentrations of enterolactone (EL) and conjugated linoleic acid (CLA). Enterolactone and CLA are endogenously produced from dietary components and have been identified as nutraceutical compounds with the potential of improving human health through the prevention and treatment of diseases. The concentration of these compounds in milk can be modulated through nutritional strategies which enable to produce milk with greater potential for improving human health. The inclusion of vegetable lignans sources, such as flaxseed meal and the inclusion of sucrose sources in the diet of dairy cows increase the concentration of EL in milk. Feeding sources of polyunsaturated fatty acids, such as vegetable oils, results in increased concentration of CLA in milk. The application of animal nutrition to increase nutraceutical properties of milk is a valuable tool for promoting the association of milk with human health benefits and is of great interest.Objetivou-se descrever estratégias nutricionais para aumentar as propriedades nutracêuticas do leite, incluindo principalmente estratégias para o aumento nas concentrações de enterolactona (EL) e ácido linoleico conjugado (CLA). Os compostos EL e CLA, ambos produzidos endogenamente a partir de componentes da dieta, são compostos bioativos presente no leite e têm sido apontados como compostos nutracêuticos, capazes de melhorar a saúde humana através da prevenção e tratamento de doenças. Estratégias nutricionais aplicadas na alimentação de vacas leiteiras possibilitam o aumento da concentração destes compostos no leite, tornando possível a produção de leite com maior potencial de beneficiamento a saúde humana. A inclusão de fontes de lignanas vegetais, como por exemplo, o farelo de linhaça e a inclusão de fontes de sacarose na dieta de vacas leiteiras possibilitam aumentar a concentração de EL no leite. Da mesma forma, o fornecimento de fontes ricas de ácidos graxos polinsaturados, como por exemplo, os óleos vegetais, possibilita o aumento da concentração de CLA no leite. A temática da nutrição animal voltada para o aumento das propriedades nutracêuticas do leite, apesar de estar iniciando, apresenta grande perspectiva, e é uma ferramenta valiosa para promoção da associação do leite com benefícios a saúde humana. Palavras-chave: nutracêutico; compostos bioativos; lignanas; vacas de leite; benefícios do leite; redução do risco de doenças.   Nutritional strategies to improve nutraceutical proprieties of milk: improvements on milk enterolactone and conjugated linoleic acid   ABSTRACT: This study aimed to describe nutritional strategies to increase milk nutraceutical properties, including mainly strategies to increase the concentrations of enterolactone (EL) and conjugated linoleic acid (CLA). Enterolactone and CLA are endogenously produced from dietary components and have been identified as nutraceutical compounds with the potential of improving human health through the prevention and treatment of diseases. The concentration of these compounds in milk can be modulated through nutritional strategies which enable to produce milk with greater potential for improving human health. The inclusion of vegetable lignans sources, such as flaxseed meal and the inclusion of sucrose sources in the diet of dairy cows increase the concentration of EL in milk. Feeding sources of polyunsaturated fatty acids, such as vegetable oils, results in increased concentration of CLA in milk. The application of animal nutrition to increase nutraceutical properties of milk is a valuable tool for promoting the association of milk with human health benefits and is of great interest. Keywords: nutraceutical proprieties; bioactive compounds; lignans; dairy cows; health benefits of milk; disease risk reduction

Caroço de algodão em dietas sem volumoso para cordeiros confinados

The objective of this work was to evaluate the performance, intake, feeding behavior, costs of production and nutritional parameters of sheep fed diets containing different levels of whole cottonseed (WC): zero, 10, 20, 30 and 40%. Two experiments have been carried out, in which in the first trial we have used a completely randomized design with five treatments and six replicates each, which lasted 70 days. The animals were kept in collective stalls and all of them have been weighed at the beginning and end of the experiment. The second experiment was a 5x5 Latin square design with five treatments and five animals divided in five periods of 14 days, totaling 70 days of experimentation. The intakes of the DM, OM, EE, NDF and NFC ave been not affected by WC levels (P>0.01). The WC levels had quadratic affect only on EE digestibility (P0.05). There were no effects (P>0.05) of whole cottonseed on average daily gain with average of 200.8g/animal/day, as well as there was no effect of the WC levels on intake behavior. A gross margins of R$0.18 to 0.19 per animal / day was observed for WC levels of 10 to 20$ 0,18 e 0,19 por animal/dia, respectivamente para os níveis 10 e 20% de caroço de algodão. Recomenda-se a inclusão de até 20% de caroço de algodão na ração de cordeiros confinados sem o fornecimento de volumoso

Macromineral and trace element requirements for Santa Ines sheep

Abstract Minerals play an important role in animal metabolism. Knowledge of mineral requirements allows well-formulated diets to be provided, which is the main factor that affects performance. To determine the macromineral and trace element requirements for growth and maintenance, thirty-eight 2-month-old Santa Ines lambs with initial body weight (BW) of 13.0 ± 1.49 kg were distributed in a factorial design with feeding levels (ad libitum, 30% and 60% feed restriction) and sex classes [castrated (CM) and intact males (IM)]. The net mineral requirements for gain were higher (P  0.05) the maintenance requirement of the trace elements Co, Cu, Zn and Cr which were 0.0015, 0.037, 0.698, and 0.0055 (mg/kg EBW0.75), respectively. Our study indicated that the Santa Ines net mineral requirements are different from the main nutritional requirements established by committees for sheep, which may result in unbalanced diets