Avaliação de indicadores para estimativa das digestibilidades parciais e total de dietas em bovinos
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Data
2007-04-01
Autores
Brito, Rodolfo Marques de
Sampaio, Alexandre Amstalden Moraes [UNESP]
Resende, Kleber Tomás de [UNESP]
Fernandes, Alexandre Rodrigo Mendes [UNESP]
Henrique, Wignez
Routman, Karina de Souza [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Zootecnia
Resumo
Avaliaram-se os indicadores fibra detergente ácido indigestível (FDAi) e óxido crômico (Cr2O3) na estimativa das digestililidades parciais e total das frações nutritivas da dieta. Foram utilizados quatro tourinhos Santa Gertrudes canulados no rúmen e no duodeno, distribuídos em delineamento quadrado latino 4 × 4 (animais ´ período) para estimativa da digestibilidade de quatro dietas compostas de feno de capim-marandu e concentrados, ajustadas para proporcionar ganho de peso corporal diário de 0,5 e 1 kg/animal e potencial de fermentação microbiana de 9,5 e 11 g de PB microbiana/MJ em fermentável. Os suplementos foram formulados com mistura mineral, milho, soja e farelos de soja e algodão. Não houve interação significativa dietas ´ indicadores. À exceção dos coeficientes de digestibilidade intestinal da MS e da FDN, todos os outros coeficientes de digestibilidade (MS, PB e CT) diferiram significativamente entre os indicadores avaliados. Quando utilizado o indicador FDAi, foram registrados maiores valores de digestibilidade ruminal e total e menores coeficientes de digestibilidade intestinal. A FDAi possibilitou melhor estimativa dos coeficientes de digestibilidade dos nutrientes das dietas, quando compostas na sua maior parte de volumosos (57 a 70% da MS).
Four Santa Gertrudis young bulls fitted with ruminal and duodenal cannula were randomly assigned to a 4 x 4 Latin square to compare ruminal, intestinal, and total tract digestibility of nutrients estimated by the internal marker indigestible acid detergent fiber (IADF) or by the external marker chromic oxide (Cr2O3). Animals were fed palisadegrass hay (Brachiaria brizantha cv. Marandu) and concentrates formulated to allow daily body weight gain of 0.5 and 1 kg and potential of microbial fermentation of 9.5 and 11 g of microbial crude protein/MJ of fermentable metabolizable energy. Concentrates contained mineral mixture, ground corn, ground soybean, soybean and cottonseed meals. There was no significant interaction between diets and markers. Except for the apparent intestinal digestibility coefficients of dry matter and neutral detergent fiber, all remaining (OM, CP, and TC) digestibility coefficients differed significantly comparing IADF with Cr2O3. When IADF was used, ruminal and total tract digestibility of nutrients were greater while intestinal digestibility was lower compared to Cr2O3. Indigestible ADF yielded the best estimates of nutrient digestibility coefficients in diets with high proportion of forage (57 to 70% of total DM).
Four Santa Gertrudis young bulls fitted with ruminal and duodenal cannula were randomly assigned to a 4 x 4 Latin square to compare ruminal, intestinal, and total tract digestibility of nutrients estimated by the internal marker indigestible acid detergent fiber (IADF) or by the external marker chromic oxide (Cr2O3). Animals were fed palisadegrass hay (Brachiaria brizantha cv. Marandu) and concentrates formulated to allow daily body weight gain of 0.5 and 1 kg and potential of microbial fermentation of 9.5 and 11 g of microbial crude protein/MJ of fermentable metabolizable energy. Concentrates contained mineral mixture, ground corn, ground soybean, soybean and cottonseed meals. There was no significant interaction between diets and markers. Except for the apparent intestinal digestibility coefficients of dry matter and neutral detergent fiber, all remaining (OM, CP, and TC) digestibility coefficients differed significantly comparing IADF with Cr2O3. When IADF was used, ruminal and total tract digestibility of nutrients were greater while intestinal digestibility was lower compared to Cr2O3. Indigestible ADF yielded the best estimates of nutrient digestibility coefficients in diets with high proportion of forage (57 to 70% of total DM).
Descrição
Palavras-chave
digestibilidade intestinal, digestibilidade ruminal, fibra em detergente ácido indigestível, óxido crômico, chromic oxide, indigestible acid detergent fiber, intestinal digestibility, ruminal digestibility
Como citar
Revista Brasileira de Zootecnia. Sociedade Brasileira de Zootecnia, v. 36, n. 2, p. 445-451, 2007.