RUMINAL BYPASS OF BREWERS DRIED GRAINS PROTEIN

Two rumen bypass trials with abomasally cannulated steers demonstrated that the protein in brewers dried grains (BDG) is resistant to degradation in the rumen. In both trials animals fed BDG or a combination of BDG and urea had consistently higher levels of total and nonammonia N reaching the abomasum than did animals fed all urea supplements and levels equal to those fed soybean meal (SBM) and urea combinations. There were no significant differences in bacterial N flow to the lower tract between protein sources in either of the trials but BDG and BDG-urea supplements produced numerically smaller means for bacterial N than did urea or SBM urea supplements. In both trials BDG and BDG-urea supplementation resulted in greater plant N flow to the abomasum when compared to urea or SBM-urea. Feeding BDG and BDG-urea diets tended to produce more valine, leucine, phenylalanine and methionine entry into the intestinal tract than feeding urea or SBM-urea rations. BDG bypass in the 2 trials was calculated at 61 and 48%; SBM bypass in trial 2 was 24%.