Nutritional performance of cattle under grazing during dry and rainy seasons supplemented with nitrogenous compounds and/or starch

Autor: Lazzarini, Isis
Přispěvatelé: Paulino, Mário Fonseca, Valadares Filho, Sebastião de Campos, Detmann, Edenio, Valadares, Rilene Ferreira Diniz, Rennó, Luciana Navajas
Jazyk: portugalština
Rok vydání: 2011
Předmět:
Zdroj: LOCUS Repositório Institucional da UFV
Universidade Federal de Viçosa (UFV)
instacron:UFV
Popis: Conselho Nacional de Desenvolvimento Científico e Tecnológico This study was prepared based upon two experiments with beef cattle in pasture constituted by Brachiaria grass (Uruchloa decumbens). One of them performed during the dry season, and the other during the rainy season. This work was carried out aiming to evaluate the effects of protein and/or starch supplementation relative to the nutritional performance of bovine under pasture during the dry and rainy seasons. The first experiment, performed during the months of July and September, five Dutch x Zebu half-breed young bulls with average body weight (BW) of 396.8 ± 13.4 kg, cannulated in the rumen and in the abomasum were used. The following experimental treatments were evaluated: 1. Control (for basal forage only). 2. Supplementation with nitrogen compounds supplied in the proportion of 1g of crude protein (CP) per kg of BW by ruminal infusion; 3. Supplementation with starch in the proportion of 2.5 g/kg of BW by ruminal infusion. 4. Supplementation with nitrogen compounds and starch as described for the treatments 1 and 2; and 5. Supplementation similar to the one described for the treatment 4 in which the starch was replaced by a mixture of starch and nitrogen compounds in such a way that the energetic portion of the supplement was 15% of the CP. The experiment was performed following the delineation in a 5 x 5 latin square, adopting a factorial scheme 2 x 2 +1 (addition or not of nitrogen supplement, addition or not of starch, and addition of energetic supplement containing 15% of the CP). The intake of pasture DM, pasture OM, NDFap, digested NDFap and NDFi were not affected (P>0.10) by any of the factors evaluated in this study. The CP consumption showed an effect of interaction of the supplement with nitrogen compounds and starch (P0.10) the CP consumption, while the additional supply of nitrogen compounds to animals supplemented with nitrogen and starch increased (P0.10), except for the CP, in which the interactive affect was observed (P0,10). Any of the other variables associated to the voluntary consumption. The supplementation with starch increased (P0.10) in respect to the control when nitrogen or starch were supplied separately, but was increased (P0.10) of the additional supply of nitrogen to the animals supplemented with nitrogen compounds and starch. The NB was increased (P0,10) por nenhum dos fatores avaliados. O consumo de nutrientes digestíveis totais (NDT) foi elevado (P0,10), com exceção da PB, no qual se observou efeito interativo (P0,10) nenhuma das demais variáveis associadas ao consumo voluntário. A suplementação com amido incrementou (P0,10) em relação ao controle quando nitrogênio ou amido foram fornecidos isoladamente, mas foi incrementado (P0,10) do fornecimento adicional de nitrogênio aos animais suplementados com compostos nitrogenados e amido. Os coeficientes de digestibilidade da MS e da MO e o nível dietético de NDT foram afetados de forma interativa (P0,10), a estimativa de BN se mostrou superior com a suplementação conjunta com amido e compostos nitrogenados em comparação à suplementação isolada com estes compostos. Diante dos resultados obtidos, concluiu-se que a suplementação com amido e compostos nitrogenados para bovinos mantidos a pasto durante o período das águas, considerando-se forragem com alto teor de proteína bruta, confere efeito interativo potencializando a digestão da matéria seca e o consumo de energia. Efeitos indiretos envolvendo aspectos metabólicos são observados, entre os quais se destaca a ampliação da retenção de nitrogênio no organismo animal.
Databáze: OpenAIRE
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