Study On Fermentation Method Of Soybean Residue And Application In Beef Cattle Feed

Bacillus subtilis natto has been used widely for producting soy food as a microbiological feed additive,but few reports were about the using effects of bacillus subtilis natto as feed additive for beef.Thus,the bacillus natto was selected for fermenting solid soybean dregs,then optimizing the fermentation conditions,finally feeding them to beef cattle in this experiment,in order to provide basic data for the production application of fermented soybean dregs.In this experiment,the water content of fermentation substrate,inoculation size,fermentation time and fermentation temperature were setup,the best fermentation technology of soybean dregs was confirmed by analyzing its nutritional composition and anti-nutritional factors after solid-state fermentation.The results showed that the best fermentation conditions were as follows:the water content in the fermentation substrate was 75%,the inoculation size was 9%,the fermentation temperature was 35? and the fermentation time was 21 h.At the moment,the content of soluble protein in fermented soybean dregs reached 13.96%.Under the optimized conditions,the contents of soluble fiber and soluble polysaccharides in fermented soybean dregs increased by 94%and 175%respectively,the content of phytic acid decreased by 50%,and the activity of trypsin inhibitor could not be detected.Crude protein,crude ash and other components changed,but the difference was not significant(P>0.05).A total of 40 Simmental cattle were randomly divided into 4 groups with 10 cows in each group in the feeding experiment of fermented soybean dregs instead of soybean meal.Fermented soybean dregs replaced 2%(experimental group 1),3.5%(experimental group 2)and 5%(experimental group 3)of soybean meal respectively,and the proportion of other components remained unchanged,and beef cattle were fed continuously for 70 days.then the effects of fermented soybean dregs on the growth,economic benefit and serum biochemical indexes of beef cattle were studied.By measuring the growth performance and serum biochemical indexes of beef cattle.The results of feeding experiment showed that compared with the control group,the daily gain of beef cattle in each test group increased by 12.63%,14.73%and 24.21%respectively,the feed-weight ratio of test group 1 and test group 2 was not significant(P>0.05),and the feed-weight ratio of test group 3 increased significantly(P>0.05).In terms of weight gain benefit,the average daily gain benefit of test group 3 was the highest,which was 30.84 yuan,and when the feed cost was 10.38 yuan,the feed cost of test group 1 and group 2 was higher than that of the control group,but the difference was not significant(P>0.05).There was no significant difference in serum biochemical indexes among the experimental groups(P>0.05),which indicated that fermented soybean dregs instead of different proportions of soybean meal had no harm to the health of beef cattle.Thus it can be seen that the soybean dregs fermented by Bacillus natto has potential application value in the production of beef cattle.