Effects Of Antimicrobial Peptide CC34 Engineered Bacteria Powder On Growth,Immunity,Antioxidant Capacity And Gastrointestinal Flora In Lambs

In order to explore the regulatory effect of antimicrobial peptide CC34 engineering bacteria powder on the growth,immunity and antioxidant properties of fattening lambs,as well as rumen and intestinal flora,this study adopted a single-factor completely randomized experimental design.Fifty-four male single-litter uncastrated lambs(small-tailed Han sheep × Northeast finewool sheep)of(50±2 days old)with good health and similar body weight were selected.Randomly divided into 3 groups: blank group(CON group),antimicrobial peptide CC34×3g group and antimicrobial peptide CC34×6g group.The fattening lambs in the control group were fed the basal diet,and the antibacterial peptide CC34×3g group and the antibacterial peptide CC34×6g group were supplemented with 3 g/kg and 6 g/kg antibacterial peptide CC34 engineering bacterial powder respectively in the basal diet.The pre-trial period is 7 days and the formal period is 30 days.On the 15 th and 30 th day of the formal period of the experiment,6 lambs were randomly selected from each group to collect samples.Through the determination of lamb apparent digestibility,serum immunity,antioxidant function,rumen fermentation parameters and gastrointestinal flora structure,the comprehensive effects of antimicrobial peptide CC34 engineered bacteria powder on the production performance of fattening lambs were explored.This test system evaluates the functional properties of the antibacterial peptide CC34 engineered bacteria powder.It is hoped to provide a theoretical basis for the application of antimicrobial peptides as antibiotic substitutes in the animal husbandry industry.Research indicates:(1)During the whole experimental period,there was no significant difference in the average daily feed intake(ADFI),average daily gain(ADG)and feed-to-weight ratio(F:G)among the groups(P>0.05).Compared with the CON group,the antimicrobial peptide CC34×6g group significantly increased the apparent digestibility of CP、ADF and Ca in fattening lambs(P<0.05),and the apparent digestibility of CP in the CC34×6g group was significantly higher than that of the CC34×3g group(P<0.05).(2)With the growth of fattening lambs,the contents of IL-2 and IL-6 in each group gradually decreased.On the 15 th day of the test period,compared with the CON group,the contents of IL-2,IL-6 and TNF-α in the CC34×3g group and CC34×6g group were significantly decreased(P<0.001);On the 30 th day of the experimental period,compared with CON,the levels of IL-2 and IL-6 in CC34×3g group and CC34×6g group were significantly decreased(P<0.001),and the content of TNF-α in CC34×6g group was significantly decreased(P<0.001).(3)During the whole test period,p H value and ammonia nitrogen concentration in the rumen fluid of fattening lambs in CC34×3g group and CC34×6g group were lower than those in control group,but the difference was not significant(P>0.05).The contents of total volatile fatty acids,acetic acid,propionic acid and butyric acid in each group increased with the extension of test time,and the contents of total volatile fatty acids,acetic acid,propionic acid and butyric acid in CC34×3g group and CC34×6g group were higher than those in the CON group(P>0.05),Among them,the CC34×6g group was the highest,and the addition of antimicrobial peptide CC34 could reduce the ratio of acetic acid/propionic acid in the rumen of fattening lambs,but the difference was not significant compared with the control group(P>0.05).(4)The addition of antimicrobial peptide CC34 engineered bacterial powder to the diet significantly reduced the diversity of gastrointestinal flora in lambs(P<0.05),and changed the richness of gastrointestinal flora;Although there was no significant effect on the gastrointestinal flora at the phylum and genus levels(P>0.05),it could increase the beneficial bacteria and reduce the relative abundance of harmful bacteria.Based on the above results,the addition of antimicrobial peptide CC34 engineered bacterial powder to the diet has a positive effect on the growth performance and apparent digestibility of fattening lambs.It can significantly enhance the immune and antioxidant properties of the body,improve the rumen fermentation capacity.Significantly adjusted the species abundance of rumen and rectal feces,and the CC34×6g group had the best effect...