Effect Of Crucian Carp Protein Peptide On Growth,Immune Response And Intestinal Microflora Of Yellow Croaker

Nibea albiflora,a genus Perciformes,Sciaenidae,and Nibea,is an important economic fish on the coast of China.This study investigated the effects of baical protein peptides on the growth performance,antioxidant capacity,immune response,and intestinal flora of yellow croaker,with the aim of providing reference value for the development of cheap and efficient aquatic feed,reducing feed costs,and improving feed quality.At the same time,it can reduce waste of resources and increase the value of use of Scutellaria baicalensis.The findings are as follows:1.The effect of baical protein peptide on the growth,antioxidant and immune response of yellow croaker.Juvenile yellow croaker larvae with an initial body weight of(5.90 � 0.08)g were randomly divided into three groups and each group consisted of three replicates for an 8-week breeding test.The results showed that:(1)There were no significant differences in survival rate,specific growth rate(SGR)and feed coefficient(FCR)among the treatment groups of juvenile yellow croaker(P> 0.05);There was no significant difference in the contents of crude fat,water and ash(P> 0.05);(2)There was no significant difference between the superoxide dismutase(SOD)activity,glutathione peroxidase(GSH-PX)activity and malondialdehyde(MDA)activity(P> 0.05);Catalase(CAT)activity in the serum of catfish was significantly higher than that of the control group(P <0.05).There was no significant difference in catalase(CAT)activity in the 2-fold group(P> 0.05).The serum alkaline phosphatase(AKP)activity in the 1-fold treatment group was significantly lower than that in the 2-fold treatment group and the control group.The acid phosphatase(ACP)and lysozyme(LZM)activities in the control group were significantly lower than the treatment group(P <0.05).(3)There was no significant difference in liver superoxide dismutase(SOD)enzyme activity and malondialdehyde(MDA)content in each treatment group(P> 0.05),and the catalase(CAT)activity in the treatment group was significantly higher than the control Group(P <0.05).The alkaline phosphatase(AKP)and lysozyme(LZM)activities of the 2-fold treatment group were significantly higher than those of the 1-fold treatment group and the control group(P <0.05).The acid phosphatase(ACP)activity of the control group was significantly lower than that of the treatment group(P <0.05).This study shows that adding a proper amount of baical protein peptide to aquatic feed does not significantly improve the growth performance and antioxidant capacity of yellow croaker,but it can significantly improve the immune capacity of larvae.2.The effect of baical protein peptide on intestinal flora of yellow croaker.The experimental design is the same as the previous experiment.After the breeding experiment,the diversity analysis was performed on the gut sampling of the zucchini.The results showed that:(1)there were 310 OUT clusters in the original feed group;320 OUT clusters in the 1-fold group;and 527 OUT clusters in the 2-fold group.(2)On the level of the phylum,the dominant intestinal flora in the three experimental groups of Pseudosciaena crocea were both soft-walled and proteobacteria,which accounted for about 90.94% of the total flora.Among them,the abundance of soft wall bacteria was larger in the original feed group and the 1-fold group,while the proteobacteria were larger in the 2-fold group.It showed that the baical protein peptide can change the abundance of the dominant phylum in the intestine of yellow croaker.(3)The genus level showed that the Mycoplasma genus was richer in the control group,and the Marivita genus and qidonghai fungus genus were increased in the treatment group.Mycoplasma are mostly pathogenic bacteria,and the Mycoplasma genus in the treatment group is significantly reduced,indicating that the baical protein peptide can inhibit the growth and reproduction of pathogenic bacteria and optimize the structure of the intestinal flora of the yellow croaker.