This experiment aimed to investigate the effects of different feed additives(complex microecological preparations,antimicrobial peptides and acidifiers)on growth performance,immune performance,intestinal health,and fecal microorganisms of weaned piglets.A total of 240 weaned piglets[(9.52±1.30)kg]with the same batch of"Duroc×Landrace×Large White"of the age of 35 days were selected and randomly divided 4 groups,with 3 replicates in each group and 20 piglets per replicate.The control group was fed a basal diet,the experimental groups were fed the basal diet supplemented separately with complex microecological preparations(1 000 g/t,microecological group),antimicrobial peptides(1 000 g/t,antimicrobial peptide group)and po-tassium diformate(1％,acidifiers group)and the experimental period was 30 days.The results showed as fol-lows:1)compared with the control group,the final weight,average daily gain(ADG)and average daily feed intake(ADFI)in microecological group and antimicrobial peptide group were significantly increased(P＜0.05),and the ratio of feed to gain was significantly decreased(P＜0.05).The diarrhea rate in control group was significantly higher than that in experimental groups(P＜0.05),and that in antimicrobial peptide group was significantly lower than that of other groups(P＜0.05).2)Compared with the control group,the contents of serum immunoglobulin A(IgA),immunoglobulin G(IgG),immunoglobulin M(IgM),CD4+T lympho-cytes(CD4)and CD8+T lymphocytes(CD8)in microecological group and antimicrobial peptide group were significantly increased(P＜0.05);the contents of serum IgG and IgM in antimicrobial peptide group were sig-nificantly higher than those in other groups(P＜0.05),but the ratio of CD4/CD8 was not significantly differ-ent among all groups(P＞0.05).The immune organ index in microecological group and antimicrobial peptide group was significantly better than that in control group(P＜0.05).3)Compared with the control group,the villus length and ileum villus length/crypt depth ratio(V/C)of ileum and jejunum in microecological group and antimicrobial peptide group were significantly increased(P＜0.05),but the crypt depth of ileum and jeju-num and jejunum V/C were not significantly different among all groups(P＞0.05).4)Compared with the con-trol group,the richness,evenness and diversity of fecal microorganisms in microecological group,antimicrobi-al peptide group and acidifier group were significantly increased(P＜0.05).The relative abundance of Firmi-cutes and Bacteroidetes in microecological group and antimicrobial peptide group was significantly increased(P＜0.05).The relative abundances of Clostridium,Lactobacillus,Prevotella and Ruminococcus,which are related to growth and immunity,were significantly increased(P＜0.05).In conclusion,dietary adding com-plex microecological preparations and antimicrobial peptides can significantly improve the ADG and ADFI of weaned piglets,reduce F/G and diarrhea rates,and significantly improve immune performance;adding com-plex microecological preparations and antimicrobial peptides can regulate gut microbiota and improve intestinal health.The optimal feed additive for weaned piglets in this study is antimicrobial peptides,followed by com-plex microecological preparations.[Chinese Journal of Animal Nutrition,2024,36(9):5581-5593]
维普
万方数据