Effects Of Active Peptide CC34 Yeast Culture On Antioxidant Capacity And Small Intestinal Barrier Function In Weaned Lambs

To investigate the effect of active peptide CC34 yeast culture on intestinal development,antioxidant capacity,and regulation of intestinal flora and nutrition in weaned lambs,this study adopted a single-factor completely randomized experimental design,twenty-four male lambs(small-tailed Han sheep×Northeast fine-wool sheep)of about 24 days of age in good condition and similar body weight(9.64±0.84 kg)were selected,they were randomly divided into 3groups,each group was 8 replicates,and they were reared in a single pen.The lambs in the control group were fed the basal diet,and the yeast culture group was supplemented with 2 g/kg of yeast engineering bacteria without the active peptide CC34 gene(the number of viable bacteria was 1×10~9CFU/g)in the basal diet.The basal diet was supplemented with 2 g/kg of active peptide CC34 yeast culture(the number of viable bacteria was 1×10~9CFU/g),the preliminary trial period was 8 days,and the formal period was 28 days.On the 14th and 28th day of the formal period of the experiment,3 lambs were randomly selected from each group for slaughter and the samples were collected,the jejunum and ileum of the lambs were analyzed by histomorphological analysis,blood antioxidant,liver antioxidant,and jejunum antioxidant indexes,amino acid transporter-related gene expression,and the determination and analysis of the bacterial community structure in jejunal chyme and ileal chyme,to explore the effect of active peptide CC34 yeast culture on weaned lambs,and to make functional characteristics of active peptide CC34 yeast culture,the data support and theoretical basis provide a certain theoretical reference value for the development of active peptides as functional additives for humans and animals in the near future.Research indicates:(1)The addition of active peptide CC34 significantly increased the villus height,villus width and villus surface area in the jejunum throughout the experimental period(P<0.05),significantly increased ileum villus width and decreased crypt depth(P<0.05).On the 14th day of the experimental period,the relative expression level of ZO-1 gene in the jejunum epithelial tissue of lambs in the active peptide CC34 yeast culture group was higher than that in the PY group and the CON group(P<0.05);the relative expression level of the Claudin-1 gene in the active peptide CC34 group;the relative expression of Claudin-1 gene in active peptide CC34group was significantly higher than that in CON group(P<0.05).(2)The addition of active peptide CC34 could significantly increase the contents of SOD,T-AOC,GSH-Px and MPO in lamb serum(P<0.05).Significantly decreased the content of MDA,NO and i NOS(P<0.05).Significantly increased the contents of T-AOC,GSH-Px and MPO in lamb liver(P<0.05),and significantly decreased the contents of MDA,NO and i NOS(P<0.05).Significantly increased the content of T-AOC in lamb jejunum(P<0.05),and significantly decreased the content of MDA and i NOS(P<0.05).(3)The addition of active peptide CC34 had no significant effect on the alpha diversity of lamb jejunum and ileum(P>0.05).However,it could increase the relative content of Firmicutes in the jejunum(P<0.05)and decrease the relative content of Actinobacteria(P<0.05)at the 14th day of the test period.The relative contents of Actinomycetes,Proteobacteria and Helicobacteria in the ileum were decreased on the 28th day of the test period(P<0.05).The relative content of Olsenella in the jejunum at the 14th day of the test period was significantly reduced(P<0.05).Significantly increased the relative content of Acetitomaculum in the ileum at 28 days of the test period(P<0.05).(4)The addition of active peptide CC34 can increase the relative expression of SMAP-29and SBD-1 genes on the 14th day of the test period(P<0.05);At 28 days,the relative expression of TLR4 gene in PY group was significantly higher than that in active peptide CC34 group and CON group(P<0.05).(5)The addition of active peptide CC34 can significantly increase the relative expression of SLC3A2 gene in the whole experiment(P<0.05);significantly increase the relative expression of SLC7A11 gene on the 14th day of the experimental period(P<0.05);significantly increase the relative expression of the SLC7A7 gene on the 28th day of the experimental period.Expression level(P<0.05).Significantly increased the relative expression of SLC7A9 gene on the 28th day of the test period(P<0.05).Significantly decreased the relative expression of SLC3A1 gene on the 14th day of the test period(P<0.05).Based on the above results,dietary addition of active peptide CC34 yeast culture can promote the development of the small intestine of weaned lambs,increase the antioxidant capacity of weaned lambs,and improve the diversity of jejunum and ileum bacteria at the phylum and genus levels.