Effect of Bentonite Supplementation on Nitrogen Metabolism from Diets Containing Urea in Cattle

In an in vitro study three substrates viz. concentrate mixture with different levels of urea (a), synthetic diets with urea (b) and urea treated straw (c) supplemented with bentonite (0, 2, 3, 4 and 6% w/w) were evaluated. IVDMD and IVOMD did not differ Irrespective of diet or level of bentonite. Ammonia -N concentration from concentrate mixture containing 1% urea decreased with the increase in bentonite level, however, at the other levels of area it remained similar irrespective of bentonite level. The peak ammonia-N level was lower at all the levels of bentonite than those without bentonite but in synthetic diets as well as in treated straw no such variation was recorded.

In an in vivo experiment twelve ruminally fistulated crossbred calves, distributed in three equal groups, were fed concentrate mixture and wheat straw ad lib. Group II and III were supplemented with 2 and 4% bentonite, respectively in concentrate mixture. N excretion and balances were similar among groups. Lower total-N and ammonia-N (P<0.01) in rumen liquor In groups II and III than in group I indicated variation in N metabolism at rumen level, however, blood N parameters were similar among all the groups, Hence, this study Indicated that ammonia -N was not adsorbed on bentonite and decrease in ammonia -N with protein diets might be due to the decrease in protein degradability.