Elect of heat treatment of soybean meal and fish meal on amino acid digestibility in mink and dairy cows.

Commercial soybean meal and fish meal were subjected to additional moist heat for 30 minutes at 120 degrees Centigrade. The heat treatment of soybean meal significantly reduced arginine, lysine and cysteine levels by 4.1, 8.2 and 12.5 percent, respectively. The digestibility of crude protein and most amino acids were reduced by heat treatment of the soybean meal in mink. In studies with dairy cows, heat treatment if soybean meal significantly reduces the rumen digestibility of crude protein and amino acids. These results demonstrate that excessive moist heat will denature soy proteins and damage selected amino acids in soybean meal. The end results are reduced amino acid digestibility in monogastric animals and greater rumen bypass in ruminants.

Ljokel, K., O.M. Harstad and A. Skreda. 2000. Elect of heat treatment of soybean meal and fish meal on amino acid digestibility in mink and dairy cows. An. Feed Sci and Techn. 84:83-95.