State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, 100093 Beijing, China.
Poult Sci. 2019 Jan 1;98(1):150-163. doi: 10.3382/ps/pey368.
This study evaluated the effects of dietary Enterococcus faecium NCIMB 11181 on growth performance and immune response in broiler chickens. A total of 360 1-day-old Arbor Acres male birds were randomly assigned to 4 treatments that administered different dosages of E. faecium (0, 5 × 107, 1 × 108, and 2 × 108 CFU E. faecium/kg diet). The results revealed that average daily gain (ADG) changed quadratically, while feed conversion rate (FCR) increased linearly from day 22 to 35 and day 1 to 35 (P < 0.05). Supplementation of E. faecium at 5 × 107CFU/kg diet resulted in increased ADG (P < 0.05) compared with the other groups. Birds fed with 2 × 108 CFU/kg E. faecium exhibited increased peripheral blood lymphocyte proliferation in response to concanavalin A (Con A) (P < 0.05) at day 35 and enhanced skin responses following phytohemagglutinin (PHA) injection (P < 0.05) at 12 h. Serum lysozyme activity at day 21 increased linearly with dietary E. faecium concentration (P < 0.05), the highest activity was observed in the 1 × 108 and the 2 × 108 CFU E. faecium groups (P < 0.01). Serum levels of proinflammatory cytokines IL-1β, IL-2, IL-6, IFN-γ, and anti-inflammatory IL-4, IL-10 changed linearly or quadratically both at the initial and final phases (P < 0.05). In addition, BSA antibody titers were significantly increased following both primary and secondary inoculation when birds were fed with 1 × 108 or 2 × 108 CFU/kg E. faecium (P < 0.05). In comparison with other groups, birds received 5 × 107 CFU E. faecium exhibited the highest levels of serum IgG (P < 0.05) at day 35. Together, our results revealed that broiler diet supplemented with 5 × 107 CFU/kg E. faecium NCIMB 11181 was appropriate in relation to growth performance under normal conditions. Upon administration with higher dosages of E. faecium NCIMB 11181, obvious immune-stimulatory effects were observed following both cell-mediated and humoral immunity.
本研究评估了饲粮中添加屎肠球菌 NCIMB 11181 对肉鸡生长性能和免疫反应的影响。选用 360 只 1 日龄雄性爱拔益加肉鸡，随机分为 4 个处理组，每个处理组 3 个重复，每个重复 30 只鸡。每个处理组分别饲喂添加 0、5×107、1×108、2×108CFU/kg 屎肠球菌 NCIMB 11181 的日粮。结果表明，肉鸡的平均日增重（ADG）呈二次曲线变化，而 22-35 日龄和 1-35 日龄的饲料转化率（FCR）均呈线性增加（P＜0.05）。与其他组相比，饲粮中添加 5×107CFU/kg 屎肠球菌 NCIMB 11181 可提高 ADG（P＜0.05）。在第 35 天，饲喂 2×108CFU/kg 屎肠球菌 NCIMB 11181 的肉鸡外周血淋巴细胞对刀豆蛋白 A（Con A）的增殖反应增强（P＜0.05），在第 12 小时，植物血球凝集素（PHA）注射后的皮肤反应增强（P＜0.05）。在第 21 天，血清溶菌酶活性随饲粮屎肠球菌 NCIMB 11181 浓度呈线性增加（P＜0.05），1×108 和 2×108CFU/kg 屎肠球菌 NCIMB 11181 组的溶菌酶活性最高（P＜0.01）。在初始和终期，血清中促炎细胞因子 IL-1β、IL-2、IL-6、IFN-γ和抗炎细胞因子 IL-4、IL-10 水平均呈线性或二次变化（P＜0.05）。此外，在首次和二次接种后，当肉鸡饲喂 1×108 或 2×108CFU/kg 屎肠球菌 NCIMB 11181 时，BSA 抗体滴度均显著增加（P＜0.05）。与其他组相比，饲喂 5×107CFU/kg 屎肠球菌 NCIMB 11181 的肉鸡在第 35 天血清 IgG 水平最高（P＜0.05）。总之，在正常条件下，饲粮中添加 5×107CFU/kg 屎肠球菌 NCIMB 11181 对肉鸡的生长性能是适宜的。当饲粮中添加较高剂量的屎肠球菌 NCIMB 11181 时，细胞免疫和体液免疫均表现出明显的免疫刺激作用。
