Effects of Soybean Meal Replaced by Fermented Plant Protein Compound on Growth,Immune, Antioxidant and Intestinal Microflora Structure of Black Carp (Mylopharyngodon piceus)北大核心CSCD

This experiment was conducted to study the effects of soybean meal replaced by fermented plant protein compound on growth, immune, antioxidant and intestinal microflora structure of black carp (Mylopharyn-godon piceus). The different proportions (1∶1 and 2∶1) of fermented cottonseed meal and fermented rapeseed meal were used to replace 0 (control group), 50% and 75% soybean meal in the basic diet, respectively, 5 kinds of isonitrogenous and isoenergetic experimental diets were prepared, and the black carp with initial weight of (6. 04 ± 0. 18) g were fed for 8 weeks. The results showed that there were no significant differences on growth performance, morphological indicators and body composition among all group (P>0.05). There were no significant differences on serum complement 3, malondialdehyde, albumin contents and lysozyme activity among all group (P>0.05). The serum complement 4 content in 50% replacement group was significantly higher than that in other groups (P<0.05), and the serum immunoglobulin M content in 75% replacement group was significantly higher than that in the control group (P<0.05). There were no significant differences on hepatopancreas superoxide dismutase, catalase, alkaline phosphatase activities and total antioxidant capacity and total cholesterol content among all group (P>0.05). There were no significant differences on intestinal α-amylase and lipase activities among all group (P>0.05), and the intestinal pepsin activity in fermented cottonseed meal and fermented rapeseed meal replacing 75% soybean meal with 1 ∶ 1 proportion group was significantly higher than that in the control group (P<0.05). The dominant microflora in intestine of black carp at the phylum level were Proteobacteria, Firmicutes, Fusobacteria and Planctomycotes, and the dominant bacteria at the genus level were Aeromonas, Cetobacterium, Ralstonia and Plesiomonas. There were no significant differences on the relative abundances of intestinal main microflora among all group (P>0.05). To sum up, under the experimental conditions, the high proportion (75%) of fermented plant protein replacing soybean meal do not cause hepatopancreas damage and intestinal microflora structure change of black carp, and even improve the activities of some immune indicators in serum and intestinal protease activity, and the compound proportion of fermented cottonseed meal and fermented rapeseed meal have no significant effects on growth performance, morphological indicators, body composition, hepatopancreas antioxidant indexes and intestinal microflora structure of black carp. © 2023 Chinese Journal of Urology. All rights reserved.