Ruminal protein metabolism and intestinal amino acid utilization as affected by dietary protein and carbohydrate sources in sheep

Open Access
Publisher Website
Google Scholar
Abstract
Eight wether lambs fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 4 × 4 Latin square design to study the effects of carbohydrate and protein sources on ruminal protein metabolism and carbohydrate fermentation and intestinal amino acid (AA) absorption. Treatments were arranged as a 2 × 2 factorial. Carbohydrate sources were com and barley; protein sources were soybean meal (SBM) and fish meal (FM). Diets contained 15.5% CP, of which 40% was supplied by SBM or FM. Corn or barley provided 39% of dietary DM that contained equal amounts of grass hay and wheat straw. Fish meal diets produced a lower (P < .05) ruminal NH3 concentration and resulted in less CP degradation and bacterial protein flow to the duodenum man did SBM diets. Replacing SBM with FM increased (P < .05) ruminal digestion of all fiber fractions. In addition, cellulose and hemicellulose digestibilities in the rumen tended to increase (P > .05) when barley replaced corn in the FM diets. Carbohydrate × protein interactions (P < .05) were observed for OM digestion in the rumen and AA absorption in the small intestine (percentage of AA entering); these interactions were highest for the barley-FM diet. These results suggest that feeding FM with barley, which is high in both degradable carbohydrate and protein, might benefit ruminants more than feeding FM with com, which is high in degradable carbohydrate but relatively low in degradable protein.

This publication has 0 references indexed in Scilit: