Research On The Application Of Fermented Okara In The Diet Of Furong Crucian Carp

In order to investigate the effects of fermented okara on the growth performance,muscle quality,serum biochemistry,antioxidant,digestive enzyme activity,intestinal tissue morphology and hindgut microbial community of Furong crucian carp.750 healthy fish with an average body weight of(25.00±2.00)g were randomly divided into twenty-five cages(1.5×1.5×1.5m).There were five treatments with five replicates(cages)per treatment.All fish were fed 0% fermented okara for 7 days,following which each group was fed diets of0%,6%,12%,18% and 24% fermented okara.The feeding trial lasted for 56 days.The experiment result shows:1)Growth performance and whole fish nutrients The addition of fermented okara significantly affected the final average weight(FW),weight gain rate(WGR)and SGR of Furong crucian carp(P<0.05),significantly reduced feed conversion ratio and body crude fat content(P<0.05).Compared with the control group,the FW,WGR and SGR in6% group were significantly increased(P<0.05).Feed conversion ratio(FCR)and crude fat content of body were significantly decreased(P<0.05).There were no significant differences in fatness,hepatobody ratio,viscerobody ratio,water content and crude protein among all groups(P>0.05).According to the regression equation analysis,when the levels of fermented okara were 6.78%,7.06% and 7.23%,the WGR and SGR were the highest,and the FCR was the lowest.2)Muscle quality The fermented okara can significantly affect the muscle firmness,adhesiveness and 48 h drip loss of Furong crucian carp(P<0.05).Compared with the control group,the hardness of the 6% addition group was significantly increased(P<0.05);the hardness of the 24% addition group was significantly decreased(P<0.05);the adhesiveness of the 12%、18% and 24% addition groups was significantly reduced(P<0.05);the 48 h drip loss in the 24% addition group increased significantly(P<0.05).There was no significant difference in elasticity,cohesion,chewability and 24 h drip loss among the groups(P>0.05).3)Anti-oxidation The addition of fermented okara can significantly affect the Total antioxidant capacity(T-AOC)and Malondialdehyde(MDA)in serum and liver,total superoxide dismutase(T-SOD)in muscle of crucian carp(P<0.05).Compared with the control group,the serum T-AOC in the 6% and 12% addition groups was significantly increased(P<0.05),the serum MDA in the 24% addition group was significantly increased(P<0.05);The liver T-AOC in the 18% and 24% addition groups was significantly increased(P<0.05).The content of MDA in liver decreased in the 6%addition group(P<0.05).The activity of muscle T-SOD in the 24% addition group was significantly increased(P<0.05).There were no significant differences in serum and liver T-SOD,T-AOC and MDA of muscle among the groups(P>0.05).4)Intestinal digestive enzymes and morphological structure The addition of fermented okara can significantly affect the activities of amylase and chymotrypsin in the intestine,and the length of the intestinal villi and the thickness of the intestinal muscle layer(P<0.05).Compared with the control group,the amylase in the 6% and 12% supplement groups was significantly increased(P<0.05);the chymotrypsin in the 24% supplement group was significantly increased(P<0.05);the height of intestinal villi in the 6%、12%and 18% supplement groups significantly increased(P<0.05);The thickness of intestinal muscle layer in the 12% addition group was significantly increased(P<0.05).There were no significant differences in trypsin,fatty acid activity and number of goblet cells among all groups(P>0.05).5)Hindgut microbial community The Alpha diversity index OUT number,Chao1,PD,Shannon and Simpson in all groups were not affected by fermented okara supplemental level(P>0.05).At the phylum level,the dominant phyla in all groups were Fusobacterium,Proteobacteria,Cyanobacteria,and Firmicutes,have no statistical difference(P>0.05).At the genus level: Cetobacter,Aeromonas,unidentified,uncultured＿bacterium,ZOR0006,Photobacter,Romboutsia,Dielma,Paeniclostridium,LD29,Candidatus＿Competibacter,Clostridium＿sensu＿stricto＿1.Compared with the control group,the 6% and 24% supplement groups of Vibrio were significantly decreased(P<0.05),and the 12% added group of Vibrio was significantly increased(P<0.05).Romboutsia and Clostridium＿sensu＿stricto＿1 in the 6% addition group were significantly higher than other groups(P<0.05).Functional Predictive Analysis Using PICRUSt.Compared with the control group,the lipid metabolism,cofactor and vitamin metabolism,energy metabolism and amino acid metabolism in the 6% supplement group were significantly increased(P<0.05);carbohydrate metabolism,nucleotide metabolism,polysaccharide synthesis and metabolism were significantly increased(P<0.05).Significantly decreased(P<0.05).In environmental information processing,signal transduction was significantly increased(P<0.05);membrane transport was significantly decreased(P<0.05);in genetic information processing,folding,classification and degradation were significantly increased(P<0.05);translation and replication and repair were significantly reduced(P<0.05).In cellular processes,cell movement,transport and catabolism were significantly increased(P<0.05);there were no significant differences in organic systems and human diseases(P>0.05).In conclusion,adding fermented okara to the diet can improve the growth performance of Furong crucian carp,and the growth performance of Furong carp and crucian carp is the best when adding 6.78% ～ 7.23%;The research results provide scientific basis and reference for the utilization of plant feed raw materials.