Extrapolating Bypass Protein Potential of Treated Soybean Meal by Degradation in Rumen-Fistulated Brahman Cattle

Abstract

Loss of dietary proteins through microbial fermentation in the rumen may deprive the ruminant animals of valuable supply of amino acids at the intestinal level. This study was conducted to determine the effectiveness of three treatment methods (heat, formaldehyde, and tannic acid) in protecting dietary protein in soybean meal (SBM) from excessive microbial degradation in the rumen to extrapolate its bypass protein potential. The treated SBM samples were incubated for 24, 48, and 72 hr in rumen–fistulated cattle.

Results showed that the different treatment methods significantly reduced the rumen degradation of dry matter (DM) in SBM for 24-hr (p<0.01), 48 hr (p<0.01) and 72-hr (p<0.05) incubation, with tannic acid treatment showing the least. In terms of crude protein (CP) degradation, all the treatment methods showed significant reduction in 24-hr (p<0.01) while heat and formaldehyde in 48-hr (p<0.05) incubation, while tannin acid treatment did not differ significantly with that of the untreated, indicating their greater potential than tannic acid in protecting dietary protein from microbial degradation in the rumen. A similar pattern of differences were observed as that of actual values in terms of rates of DM and CP degradation. Overall, heat and formaldehyde treatments can effectively increase the potential of dietary protein to supply the needed amino acids in the intestines.