Effect And Mechanism Of Fermented Feed On Penaeus Vannamei

The increasingly polluted environment threatens the safety of cultured shrimp.The use of antibiotics not only disturbs the normal flora of the digestive tract of the shrimp,but also makes the pathogens resistant.The residues of the drug in the environment and the shrimp ultimately threaten human health and safety.The fermented feed is a biological fermented feed which is a biological feed fermentation strain,which converts feed protein into microbial bacterial protein,bioactive small peptide amino acid and microbial active probiotic,and can also remove anti-nutritional factors in feed.It is widely used in livestock and poultry farming.In view of this,we investigated the effects of fermented feed on the growth,immunity and intestinal flora of Penaeus vannamei by mixing the probiotics with the feed.In this paper,the basal feed was fermented with Bacillus licheniformis,Candida utilis,and Lactobacillus plantarum.The nutrients such as constant components,soluble protein content,amino acid content and fatty acid content of the feed before and after fermentation were compared and compared.Fermented feed was fed.Penaeus vannamei lasted for 6 weeks.At the end of the experiment,the growth index,non-specific immune index and immune-related factor gene expression of the shrimp were measured,and the digestive enzyme activity index was determined.The composition of the intestinal flora of the shrimp was analyzed to study the effect of the fermented feed on the shrimp.In order to study the effect and mechanism of fermented feed on Penaeus vannamei.The results showed that the contents of nutrients such as crude protein,soluble protein and polyunsaturated fatty acid in the fermented feed were significantly higher than those in the control group(p<0.05,p<0.01),which improved the quality of the feed.The fermented feed significantly improved the shrimp.The survival rate(p<0.05)also significantly enhanced the activity of non-specific immune enzymes in shrimp,significantly increasing the activity of lysozyme(LZM)and alkaline phosphatase(AKP)(p<0.01);The expression levels of the immunologically related genes proPO and IMD in the pancreas were also significantly increased(p<0.05,p<0.01).And the activities of four digestive enzymes in the stomach,hepatopancreas and intestine of shrimp were improved to different extents;the diversity index of intestinal flora of shrimp fed with fermented feed was significantly higher than that of the control group,beneficial microorganisms(Bacillus licheniformis and Lactobacillus plantarum)The abundance of species increased significantly.In summary,the fermented feed used in this experiment significantly improved the nutritional value of the feed,improved the bacterial environment in the intestinal tract of the Penaeus vannamei,and improved the digestion and absorption rate of the shrimp and the defense and disease resistance of the immune system.