Nitrogen Utilization and Digestibility by Growing Steer and Goats of Diets that Contain Monensin and Low Crude Protein

Abstract
Two digestion and metabolism experiments were conducted to determine effects of monensin in low-protein diets. Monensin supplementation (27 mg/kg of diet dry matter) of steers (303 kg) fed 8.7% crude protein increased (P<.01) apparent N digestibility and N retention and decreased (P<.01) percentage of N apparently absorbed lost in urine. Apparent digestibilities of dry matter, gross energy and acid detergent lignin were increased (P<.05). Digestibilities of neutral detergent and acid detergent fibers were not affected by monensin. In growing wether goats (15 kg) fed 8.5% crude protein, monensin (23 mg/kg of diet dry matter) improved (P<.01) apparent N digestibility and apparent N absorption. However, urinary N excretion also increased (P<.05), resulting in no difference in N retention. Monensin did not affect digestibilities of dry matter or gross energy. Efficiency of feed conversion and average daily gain were improved with monensin supplementation of growing goats fed a low-protein, high-roughage diet. Monensin resulted in typical shift of acetate-to-propionate ratio in both experiments. Results suggest that improved N utilization may account for some benefits of feeding monensin. Copyright © 1986. American Society of Animal Science. Copyright 1986 by American Society of Animal Science.

This publication has 0 references indexed in Scilit: