本试验旨在研究饲粮中添加屎肠球菌对断奶仔猪生长性能、肠道菌群和免疫功能的影响。选用255头(35±1)日龄断奶的"杜×长×大"三元杂交仔猪,随机分为5个组,每个组3个重复,每个重复17头仔猪。对照组饲喂基础饲粮(不添加抗生素和屎肠球菌);抗生素组在基础饲粮中添加8 mg/kg黄霉素和90 mg/kg阿散酸;屎肠球菌3个试验组在基础饲粮中分别添加100、300、500 mg/kg屎肠球菌。试验期为35 d。结果表明:1)与对照组相比,饲粮中添加屎肠球菌对仔猪平均日采食量(ADFI)、平均日增重(ADG)、料重比(F/G)没有显著影响(P>0.05),但添加100、300 mg/kg的屎肠球菌有提高仔猪ADFI的趋势(P>0.05),添加500 mg/kg的屎肠球菌有降低仔猪F/G的趋势(P>0.05)。与抗生素组相比,饲粮中添加屎肠球菌对仔猪ADG、ADFI、F/G均无显著影响(P>0.05)。2)与对照组相比,饲粮中添加300、500 mg/kg的屎肠球菌显著增加仔猪盲肠中乳酸杆菌的数量(P<0.05);与抗生素组相比,饲粮中添加100、300、500 mg/kg的屎肠球菌对其数量没有显著影响(P>0.05)。与对照组相比,饲粮中添加500 mg/kg的屎肠球菌显著降低仔猪结肠中大肠杆菌的数量(P<0.05),添加300、500 mg/kg的屎肠球菌显著增加仔猪结肠中乳酸杆菌数量(P<0.05);与抗生素组相比,饲粮中添加300、500 mg/kg的屎肠球菌显著增加仔猪结肠中乳酸杆菌数量(P<0.05)。3)与对照组相比,饲粮中添加300 mg/kg的屎肠球菌显著提高仔猪脾脏重量和脾脏指数(P<0.05)。与抗生素组相比,饲粮中添加300、500 mg/kg的屎肠球菌可显著提高仔猪脾脏重量(P<0.05)。4)与对照组相比,饲粮中添加300、500 mg/kg的屎肠球菌显著提高仔猪血液中淋巴细胞数量及淋巴细胞比率(P<0.05),添加100、300、500 mg/kg的屎肠球菌显著提高血清中免疫球蛋白G(IgG)含量(P<0.05),添加300、500 mg/kg的屎肠球菌显著提高血清中免疫球蛋白M(IgM)含量(P<0.05)。与抗生素组相比,饲粮中添加300、500 mg/kg的屎肠球菌显著提高仔猪血液中淋巴细胞比率及血清中IgM含量(P<0.05),添加100、300、500 mg/kg的屎肠球菌显著提高血清中IgG含量(P<0.05)。综上所述,仔猪饲粮中添加屎肠球菌可以改善仔猪生长性能,维持仔猪肠道菌群平衡,有效增强仔猪免疫力,其中以添加500 mg/kg效果最好。

Two hundred and fifty-five weaner piglets [(35?1) days of age, Duroc譒andrace譟orkshire] were used to study the effects of Enterococcus faecium on the growth performance, intestinal flora and immune function. These piglets were randomly allocated into 5 groups with 3 replicates per group and 17 piglets per replicate in a complete randomized design. The control group was fed a basal diet only, antibiotic group was fed the basal diet+8 mg/kg flavomycin and 90 mg/kg arsanilic, and the three Enterococcus faecium groups were fed the basal diet+100, 300, 500 mg/kg Enterococcus faecium, respectively. The experiment lasted for 35 days. The results showed as follows: 1)compared with the control group, average daily gain (ADG), average daily feed intake (ADFI) and feed/gain (F/G) had no significant difference among 5 groups (P>0.05); the addition of 100 and 300 mg/kg Enterococcus faecium tended to increase ADFI (P>0.05); the supplementation of 500 mg/kg Enterococcus faecium tended to reduce F/G (P>0.05). Compared with the antibiotic group, there were no significant differences in ADG, ADFI and F/G when piglets fed diets with Enterococcus faecium (P>0.05). 2) Compared with the control group, diets supplemented with 300 and 500 mg/kg Enterococcus faecium significantly increased the number of Lactobacillus in caecum (P<0.05), and there was no significant difference between the Enterococcus faecium group and the antibiotic group (P>0.05). Compared with the control group, the diet supplemented with 500 mg/kg Enterococcus faecium significantly reduced the number of Escherichia coli in colon (P<0.05), and the supplementation of 300 and 500 mg/kg Enterococcus faecium significantly increased the number of Lactobacillus in colon (P<0.05). Compared with the antibiotic group, the supplementation of 300 and 500 mg/kg Enterococcus faecium significantly increased the number of Lactobacillus in colon (P<0.05). 3) Compared with the control group, the supplementation of 300 mg/kg Enterococcus faecium significantly increased spleen weight and spleen index of piglets (P<0.05). The addition of 300 and 500 mg/kg Enterococcus faecium in the diets significantly increased spleen weight compared with the antibiotic group (P<0.05). 4) Compared with the control group, adding 300 and 500 mg/kg Enterococcus faecium significantly improved the number of lymphocyte and lymphocyte rate in blood of piglets (P<0.05); the supplemetation of Enterococcus faecium significantly increased the content of immunoglobulin G (IgG) in serum of piglets (P<0.05); the supplementation of 300 and 500 mg/kg Enterococcus faecium significantly increased the content of immunoglobulin M (IgM) in serum of piglets (P<0.05). Compared with the antibiotic group, the addition of 300 and 500 mg/kg Enterococcus faecium in the diets significantly improved lymphocyte rate in blood and the content of IgM in serum of piglets (P<0.05), and the supplemetation of Enterococcus faecium significantly increased the content of IgG in serum of piglets (P<0.05). It is concluded that Enterococcus faecium will be an ideal feed additive to improve the growth performance, regulate intestinal microflora balance and the immune function in piglets and the optimum supplemental level of Enterococcus faecium is 500 mg/kg.