溶菌酶二聚体对产肠毒素大肠杆菌攻毒断奶仔猪生长性能、肠道形态和肠道微生物菌群结构的影响OA

The experiment aimed to investigate the effects of lysozyme dimer on the growth performance,organ indices,serum biochemical indices,intestinal mucosal antioxidant capacity,intestinal morphology,and intestinal microbiota counts of weaned piglets before and after challenge with enterotoxigenic Escherichia coli(ETEC).A total of 400 healthy DLY(Duroc×Landrace×Yorkshire)weaned piglets with an initial body weight of(6.82±0.10)kg were randomly divided into four groups,with 20 replicates per group and five piglets per replicate.The control group(group CON)was fed a basal diet,the group L was fed the basal diet+1 500 mg/kg lysozyme dimer,the group ET was fed the basal diet+orally administered with 20 mL of 0.01%Escherichia coli broth,the group LE was fed the basal diet+1 500 mg/kg lysozyme dimer+orally administered with 20 mL of 0.01%Escherichia coli broth.The pre-test period was three days,and the formal test period was 14 days.The results showed that compared with the group CON,the relative weights of the duodenum and jejunum in the group ET were significantly decreased(P<0.05).Compared with group ET,the relative weights of the duodenum and jejunum in the group LE were significantly increased(P<0.05).Compared with the group CON,the serum total protein(TP)and globulin(GLB)concentrations in the group L were significantly decreased(P<0.05),while the albumin/globulin(A/G)was significantly increased(P<0.05).Compared with the group ET,the serum TP and GLB concentrations in the group LE were significantly decreased(P<0.05),while the A/G was significantly increased(P<0.05).Compared with the group CON,the villus height to crypt depth ratios of the jejunum and ileum in the group L were significantly increased(P<0.05).Compared with the group ET,the villus height to crypt depth ratios of the jejunum and ileum in the group LE were significantly increased(P<0.05).Compared with the group CON,the number of Bifidobacterium in the ileum of the group ET was significantly decreased(P<0.05).Compared with the group ET,the number of Bifidobacterium in the ileum,as well as the numbers of Lactobacillus and Bifidobacterium in the colon of the group LE were significantly increased(P<0.05),while the number of Escherichia coli in the colon was significantly decreased(P<0.05).The study shows that dietary supplementation with 1 500 mg/kg lysozyme dimer can improve serum biochemical indices and intestinal morphology,and maintain intestinal microbiota homeostasis in weaned piglets.Moreover,lysozyme dimer can alleviate the disruption of intestinal morphology and microbial balance induced by ETEC challenge,thereby protecting the intestinal health of weaned piglets.