Protein and starch sources varying in rumen degradability on nutrient digestibilities, ruminal and blood parameters of nelore steers. / Digestibilidade de nutrientes e parâmetros ruminais e sanguíneos de novilhos nelore alimentados com fontes protéicas e energéticas com diferentes degradabilidades ruminais.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

Four Nelore steers, cannulated in the duodenum and in the rumen, averaging 300 kg of live weight, were used in a 4x4 Latin Square design, to test the improvement of ruminal synchronization of starch and protein degradation. Two methods of corn processing (fine grinding (1,5mm) vs steam flaking (300g/l)) and 2 protein sources (soybean meal vs urea) were compared in a 2x2 factorial arrangement. The diets contained 13% of tropical grass hay and 87% of concentrate, averaging 13% CP and 83% TDN. Steam flaking of corn decreased (P<0,01) starch concentration in duodenal digesta, suggesting a higher ruminal degradation of this nutrient. This would explain the actual decrease in ruminal N-NH3 (P<0,01) and pH (P<0,15) and the increase in molar concentration of ruminal C3 (P<0,01). PUN concentration was decreased (P<0,01) by steam flaking of corn compared to fine grinding. The probable increase of starch degraded in the rumen and post rumen, due to steam flaking, increased (P<0,01) digestibility of this nutrient in the total tract (89,22 x 98,90%), compared to fine grinding. However, the total tract DM digestibility was not increased (P>0,05) by steam flaking, probably due to the decrease (P<0,01) in NDF digestibility. The replacement of soybean meal by urea had no effect (P>0,05) on ruminal fermentation and on intake and total tract digestion of nutrients.

ASSUNTO(S)

degradation dieta animal feedlot digestibility digestabilidade animal diet nelore steer novilho nelore fermentação ruminal fonte protéica nutrição animal ruminal fermentation confinamento animal animal nutrition degradação protein source

ACESSO AO ARTIGO

Documentos Relacionados