Department of Animal Science, University of Manitoba, Winnipeg, Canada.
Poult Sci. 2013 Aug;92(8):2084-90. doi: 10.3382/ps.2012-02947.
An experiment was conducted to investigate the supplementation of direct-fed microbials (DFM) as an alternative to antibiotics on growth performance, immune response, cecal microbial population, and ileal morphology of broiler chickens. A total of 800 one-day-old male broiler chicks (Ross × Ross) were randomly allotted to 4 dietary treatments with 4 replicate pens per treatment (50 birds/replicate pen). The 4 dietary treatments fed for 35 d were a corn-soybean meal basal diet (control); control plus 0.1% virginiamycin, as an antibiotic growth promoter (AGP); control plus 0.1% direct-fed microbials that contained Lactobacillus reuteri (DFM 1); and control plus 0.1% direct-fed microbials that contained a mixture of L. reuteri, Bacillus subtilis, and Saccharomyces cerevisiae (DFM 2). Results showed that dietary AGP and DFM supplementation significantly increased (P < 0.05) the BW gain of broilers during 0 to 21 d. The feed intake was reduced, whereas the feed conversion was improved significantly when birds were fed DFM 2 at 0 to 7 d of age. The white blood cell and monocyte levels were significantly higher in the DFM 2 group compared with the control. In addition, feeding DFM significantly (P < 0.05) increased the plasma immunoglobulin levels where a higher level was observed in DFM 2 compared with those of the other treatments. Neither DFM nor AGP treatments affected the cecal Lactobacillus and Salmonella content; however, cecal Escherichia coli content significantly decreased in broiler chickens fed DFM and AGP. The ileal villus height, and width and total thickness of muscularis externa were significantly increased when birds were fed DFM compared with AGP and control. These results indicate that the dietary supplementation of DFM increases the growth performance of birds at an early age, stimulates the immune response, decreases the number of E. coli, and improves the ileal morphology of broiler chickens. Thus, DFM that contained a mixture of several beneficial microorganisms could be a viable alternative to antibiotics in the broiler diets.
进行了一项实验，以研究直接饲喂微生物（DFM）作为抗生素替代品对肉鸡生长性能、免疫反应、盲肠微生物种群和回肠形态的影响。将 800 只 1 日龄雄性肉鸡（罗斯×罗斯）随机分配到 4 种日粮处理中，每个处理有 4 个重复栏（每个重复栏 50 只鸡）。在 35 天的试验期间，这些鸡分别饲喂 4 种日粮：玉米-豆粕基础日粮（对照组）；对照组添加 0.1%维吉尼亚霉素，作为抗生素生长促进剂（AGP）；对照组添加 0.1%含有罗伊氏乳杆菌的直接饲喂微生物（DFM1）；对照组添加 0.1%含有罗伊氏乳杆菌、枯草芽孢杆菌和酿酒酵母混合物的直接饲喂微生物（DFM2）。结果表明，日粮中添加 AGP 和 DFM 显著提高了 021 日龄肉鸡的体重增重（P＜0.05）。在 07 日龄时，饲喂 DFM2 降低了饲料摄入量，提高了饲料转化率。与对照组相比，DFM2 组的白细胞和单核细胞水平显著升高。此外，饲喂 DFM 显著（P＜0.05）提高了血浆免疫球蛋白水平，DFM2 组的水平高于其他处理组。DFM 和 AGP 处理均未影响盲肠乳酸菌和沙门氏菌含量，但饲喂 DFM 和 AGP 降低了肉鸡盲肠大肠杆菌含量。与 AGP 和对照组相比，饲喂 DFM 显著增加了肉鸡的回肠绒毛高度、宽度和外肌总厚度。这些结果表明，日粮中添加 DFM 可提高早期肉鸡的生长性能，刺激免疫反应，减少大肠杆菌数量，改善肉鸡回肠形态。因此，含有多种有益微生物的 DFM 可能是肉鸡日粮中抗生素的替代品。
