Estimation of protein intestinal digestibility of feeds by means of three-steps technique

[摘要] - The objective of this research was to estimate the intestinal digestibility of rumen-undegradable protein (RUDP) by a three-steps procedure. The evaluated feeds were the soybean meal, cottonseed meal, wheat middlings, corn meal, corn gluten meal, whole raw soybean, whole raw cottonseed, fishmeal, meat meal and blood meal. Firstly, the feeds were incubated in rumen during 16 hours to determine the rumen-undegradable protein, the residue was incubated with pepsin solution during 1 hour, and pancreatic solution during 24 hours at 380C, whose residues were analyzed for total nitrogen. The RUDP ranged from 18,83% to 94%, and the estimates of intestinal digestion of RUDP ranged from 25,07 to 83,25%. The corn gluten meal and soybean meal were the feeds that presented better intestinal digestibility, and the whole raw soybean and wheat middlings, the lowest digestibility. Although some formulation systems for ruminant diets suggest that the RUDP presents constant intestinal digestibility, the data obtained in this study suggest that this was changeable.

[学科分类] 兽医学

[关键词] digestibility;small intestine;protein;ruminant   IntroduçãoAs exigências em proteína metabolizável dos ruminantes são atendidas pela proteína microbiana produzida no rúmen;proteína dietética que escapa à fermentação ruminal e proteína endógena (DE BOER et al