本试验旨在研究复合菌培养物及酵母β-葡聚糖对肉羊生长性能与免疫功能的影响。试验选取50日龄断奶健康公羔羊105只，随机分为3组，每组5个重复，每个重复7只羔羊。对照组饲喂全混合日粮（TMR），试验Ⅰ组在TMR中添加复合菌培养物（前期添加量为50 g/kg，中期与后期添加量为70 g/kg），试验Ⅱ组在TMR基础上额外添加酵母β-葡聚糖（75 mg/kg），试验期共137 d，其中预试期7 d，正试期130 d。在试验第1、30、60、90和130天空腹称肉羊体重，测定生长性能指标，并且在试验第1、30、60和90天采集血样，测定免疫指标。结果表明：1）与对照组相比，试验Ⅰ组和Ⅱ组平均体重分别提高了10.02%和5.05%（P<0.05），屠宰率分别提高了1.29%和1.10%（P>0.05），料重比分别降低了10.33%（P<0.05）和4.21%（P>0.05）。2）与对照组相比，试验Ⅰ组血清中酸性磷酸酶活性和溶菌酶含量显著提高（P<0.05），试验Ⅰ组血清中免疫球蛋白G（IgG）、免疫球蛋白M（IgM）、白细胞介素-lβ（IL-lβ）、白细胞介素-2（IL-2）、白细胞介素-6（IL-6）、干扰素-γ（INF-γ）、肿瘤坏死因子-α（TNF-α）、CD₃⁺含量及CD₄⁺/CD₈⁺显著提高（P<0.05），试验Ⅱ组血清中IgG、IgM、IL-lβ含量显著提高（P<0.05）。综上，复合菌培养物和酵母β-葡聚糖二者均可以显著提高肉羊平均体重；复合菌培养物显著提高肉羊的特异性免疫、非特异性免疫功能及降低料重比；酵母β-葡聚糖显著提高肉羊的特异性免疫功能。

The purpose of this experiment was to study the effects of compound bacteria culture and yeast β-glucan on the growth performance and immune function of mutton sheep. In the experiment, 105 healthy weaned male lambs aged 50 days were randomly divided into 3 groups. The control group was fed a basal total mixed ration (TMR) diet, while the test group I was fed diets supplemented with a compound bacteria culture (50 g/kg in the early stage and 70 g/kg in the middle and late stages) and the test group Ⅱ was fed the TMR diet added with yeast β-glucan (75 mg/kg). The test lasted for 137 days including a 7-d preliminary period and a 130-d test period. The growth performance indicators were evaluated by lamb weights at days 1, 30, 60, 90, and 130, and the blood samples were collected at days 1, 30, 60, and 90 to determine the immune parameters. The results showed as follows:1) compared with the control group, the average body weights in test groups Ⅰ and Ⅱ increased by 10.02% and 5.05% (P<0.05), respectively; the dressing percentages increased by 1.29%and 1.10% (P>0.05); the feed/gain decreased by 10.33% (P<0.05) and 4.21% (P>0.05). 2) Compared with the control group, the serum acid phosphatase activity and lysozyme content of test group Ⅰ significantly increased (P<0.05); the contents of immune globulin G, immune globulin M, CD₃⁺, interleukin-lβ, interleukin-2, interleukin-6, interferon-γ, tumor necrosis factor-α and CD₄⁺/CD₈⁺ in the serum of test group Ⅰ significantly enhanced (P<0.05), and the contents of immune globulin G, immune globulin M, interleukin-lβ, of test group Ⅱ significantly significantly increased (P<0.05). This results indicate that both the compound bacteria culture and yeast β-glucan can significantly increase the average body weight of lambs. Moreover, the compound bacteria culture not only markedly improve the specific and non-specific immunity but also reduce the feed/gain; yeast β-glucan dramatically increase the specific immunity of mutton sheep.