Consumo e digestibilidade total e parcial de dietas utilizando farelo de girassol e três fontes de energia em novilhos confinados
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Data
2005-04-01
Autores
Mendes, Ana Rosália [UNESP]
Ezequiel, Jane Maria Bertocco [UNESP]
Galati, Rosemary Laís [UNESP]
Bocchi, Adriana Luize [UNESP]
Queiróz, Mário Adriano Ávila
Feitosa, José Valmir [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Zootecnia
Resumo
Avaliaram-se o consumo alimentar, a digestibilidade parcial e total e o balanço de nitrogênio, em novilhos confinados. Foram utilizados três novilhos de corte cruzados, canulados no rúmen e no duodeno, distribuídos em dois delineamentos em quadrado latino 3 x 3. As dietas experimentais foram constituídas de 60% de silagem de milho, tendo como fonte de proteína o farelo de girassol e, como fonte de energia, o milho (MI). O milho foi substituído parcialmente pela casca de soja (CS) ou pelo farelo de gérmen de milho (FGM). Quatro indicadores internos (lignina e FDA, FDN e lignina indigestíveis) foram submetidos a 144 horas de digestão in vitro, para estimativa da digestibilidade parcial e total das dietas. Houve maior ingestão dos componentes fibrosos na dieta CS, porém não foi observado efeito sobre o consumo de matéria seca. A lignina subestimou significativamente a digestibilidade. A utilização da FDAi, FDNi e lignina-i para estimar a digestibilidade total é viável, no entanto, a FDAi e lignina-i não estimaram adequadamente as digestibilidades parciais. Houve efeito significativo na digestibilidade ruminal da FDA, com valores mais elevados para CS e semelhantes para FGM, em relação à dieta MI. A digestibilidade total da FDA foi maior na dieta CS, porém, as digestibilidades dos demais componentes não foram afetadas pelas diferentes fontes energéticas. Não houve diferença significativa para a digestibilidade da energia e nos valores obtidos de NDT, com média de 61,5%. A casca de soja e o farelo de gérmen de milho, em substituição parcial do milho, mostraram-se fontes alternativas satisfatórias para a inclusão na dieta de bovinos.
Feed intake, partial and total digestibility and nitrogen balance were evaluated in confined steers. Three crossbreed steers, rumen and duodenum cannulated, were allotted to two 3 x 3 Latin square experimental design. The experimental diets were composed by corn silage (60%) and concentrate with sunflower meal as protein source and ground corn as energy source (MI). The ground corn was partially substituted by soybean hulls (CS) or by corn germ meal (FGM). Lignin and indigestible ADF (iADF), NDF (iNDF) and lignin (i-lignin) determined by 144 h of in vitro digestion were used as markers to estimate the total and partial diet digestibility of diets. The fiber intake was higher on CS diet, however no effect on dry matter intake was observed. Lignin underestimated significantly the digestibility. Indigestible ADF, iNDF and i-lignin was able to estimate total digestibility, however iADF and i-lignina did not estimate adequately the partial digestibility. Ruminal ADF digestibility was influenced by diets with higher values for CS and similar values for FGM, in relation to MI. Total ADF digestibility was higher in diet CS, but the other nutrients digestibility were not affected by different energy sources. Energy digestibility and NDT values did not differ among diets, with average of 61.5%. Soybean hulls and corn germ meal, on partial substitution of ground corn, were satisfactory alternative sources for inclusion on steer diets.
Feed intake, partial and total digestibility and nitrogen balance were evaluated in confined steers. Three crossbreed steers, rumen and duodenum cannulated, were allotted to two 3 x 3 Latin square experimental design. The experimental diets were composed by corn silage (60%) and concentrate with sunflower meal as protein source and ground corn as energy source (MI). The ground corn was partially substituted by soybean hulls (CS) or by corn germ meal (FGM). Lignin and indigestible ADF (iADF), NDF (iNDF) and lignin (i-lignin) determined by 144 h of in vitro digestion were used as markers to estimate the total and partial diet digestibility of diets. The fiber intake was higher on CS diet, however no effect on dry matter intake was observed. Lignin underestimated significantly the digestibility. Indigestible ADF, iNDF and i-lignin was able to estimate total digestibility, however iADF and i-lignina did not estimate adequately the partial digestibility. Ruminal ADF digestibility was influenced by diets with higher values for CS and similar values for FGM, in relation to MI. Total ADF digestibility was higher in diet CS, but the other nutrients digestibility were not affected by different energy sources. Energy digestibility and NDT values did not differ among diets, with average of 61.5%. Soybean hulls and corn germ meal, on partial substitution of ground corn, were satisfactory alternative sources for inclusion on steer diets.
Descrição
Palavras-chave
carbohydrate source, corn germ meal, internal markers, soybean hulls, Casca de soja, farelo de gérmen de milho, fonte de carboidrato, indicadores internos
Como citar
Revista Brasileira de Zootecnia. Sociedade Brasileira de Zootecnia, v. 34, n. 2, p. 679-691, 2005.