Influence of Tannins on the Nutritive Value of Soybean Meal for Ruminants1

Abstract

In vitro studies were conducted to determine the extent of proteolysis of tannin-treated soybean meal by rumen fluid and digestive enzymes. Treatment of soybean meal with 10% tannin resulted in a 90% decrease of deamination of the soybean meal. Pepsin digestion of tanned soybean meal was not affected by level or type of tannin used, however, pancreatin digestion of the protein decreased significantly (P<.01) with increasing levels of tannin. Average daily gains, feed efficiencies and nitrogen balances were greater in lambs receiving soybean meal tanned with 10% tara tannin. Efficiency of nitrogen utilization appeared to be enhanced due to tannin treatment.