日粮添加复合益生菌对羔羊生长性能、胴体品质及肠道健康的影响OA

This experiment was conducted to investigate the effects of compound probiotics on growth performance,carcass quality,and intestinal health indicators of lambs.A total of 60 3-month-old Dorper×Small-tailed Han crossbred male lambs with similar body weights(28.5±2.1 kg)were randomly assigned to 4 treatment groups,each with 3 replicates of 5 lambs per replicate.Lambs in the control group(CON)received a basal diet,whereas those in the treatment groups(T1,T2,and T3)were offered the basal diet supplemented with 0.05％,0.10％,and 0.15％compound probiotics,respectively.The probiotic product contained Lactobacillus plantarum,Bacillus subtilis,and Saccharomyces cerevisiae,with a total viable count≥1.0×109 CFU/g.The adaptation period lasted 10 days,followed by a 70-day formal experimental period.Results indicated that:(1)lambs in the T2 and T3 groups exhibited significantly greater final body weight and average daily gain(P<0.05),along with a markedly lower feed-to-gain ratio(P<0.05),compared with the CON group;no significant differences were detected between the T1 and CON groups for these parameters(P>0.05).(2)Pre-slaughter body weight,carcass weight,dressing percentage,and loin eye area in the T2 and T3 groups were all significantly superior to those in the CON group(P<0.05).(3)Villus height in the duodenum,jejunum,and ileum was significantly increased in the T2 and T3 groups(P<0.05),while crypt depth was significantly decreased(P<0.05),resulting in a significantly elevated villus height-to-crypt depth ratio across all three intestinal segments(P<0.05).(4)Serum concentrations of immunoglobulin G(IgG)and immunoglobulin M(IgM)in the T2 and T3 groups were significantly higher than those in the CON group(P<0.05),whereas the diarrhoea rate was significantly lower(P<0.05).Collectively,these findings suggest that dietary supplementation with 0.10％compound probiotics effectively enhances growth rate,improves carcass characteristics,promotes small intestinal mucosal development,and strengthens humoral immune responses in lambs,simultaneously effectively reducing the incidence of diarrhea,with this inclusion level yielding the most favourable overall outcomes under the present experimental conditions.