To heat the pods contains some undesirable substances, such as antitrypsin, substances that produce goiter, saponins and haemagglutinin. The presence of antitrypsin reduces the ability of the small intestine to digest and absorb proteins, reduces the amount of protein that can actually be absorbed by cattle in pods, and can easily cause diarrhea. Yak performance is even more pronounced. Feeding large amounts of raw soybean meal for a long period of time can also cause pathological enlargement and goiter of the bovine pancreas, leading to disordered metabolism of the cattle. The above-mentioned undesirable substances will lose their effect after a suitable heat treatment such as heating to 110°C for 3 minutes. And heat treatment can reduce protein digestion in the rumen, reduce ruminal ammonia loss, increase rumen protein content, thereby increasing the intestinal digestion and absorption of protein in soybean meal, significantly improve the conversion efficiency of soybean meal in feeding cattle. It should be noted that the heat treatment should be appropriate, and the overheating will denature the protein of the soybean meal and reduce its nutritional value.
The particle size of the soybean meal should be appropriate with a diameter of 0.9 to 2.5 mm (8 to 20 mesh). An excessively small particle size causes a large amount of ammonia to be produced in the rumen of the cow, resulting in the loss of protein, and in severe cases it may cause bovine ammonia poisoning. An excessively large particle size will lead to incomplete digestion, thereby lowering the feeding value.
When used with the taboo, raw soybean meal contains urease, which decomposes urea to produce ammonia and carbon dioxide. Therefore, raw soybean meal cannot be mixed with urea.