NITROGEN ADDITIVES TO CORN SILAGE FED TO GROWING CALVES

Abstract
Three separate experiments were conducted to investigate performance of light-weight calves fed corn silage supplemented with different non-protein nitrogen (NPN) sources added at ensiling time. In one experiment NPN was also added at feeding time. For calves up to approximately 290 kg body weight all supplements containing only NPN reduced weight gains by approximately 0.10–0.15 kg/day compared to soybean meal or low-urea supplements. Corn silage treated with NPN silage additives resulted in reduced dry matter intake compared to soybean meal supplementation. Thus, the effect on feed efficiency was not as great as on weight gains. Treated silages tended to be higher in pH and lactic acid but lower in acetic acid content. A large portion of the NPN added at ensiling time was analyzed as ammonia in the silages. Also, true protein content of the treated silages tended to be higher than that of the controls.