| 摘要: |
| 通过饲养试验研究微生物饲料添加剂益生康(YSK)对肉仔鸡营养代谢和免疫功能的调控机理。1000只肉仔鸡分为5个处理,在基础日粮中分别添加0,0.05%,0.1%,0.2%(质量分数,下同)的益生康和10mg/kg黄霉素。7和14日龄,在肉仔鸡胫部注射0.5mL含量为5g/L的牛血清白蛋白(BSA)抗原,试验结果表明:1)YSK的最佳添加量为0.1%,能显著提高肉仔鸡生长、增重和饲料转化效率(P<0.05),效果优于添加黄霉素;2)YSK能显著刺激肉仔鸡胸腺、脾脏和法氏囊的生长发育,增强T和B淋巴细胞活性,提高血清球蛋白的含量和抗体水平;3)YSK能明显增加血清总蛋白、球蛋白含量,并能提高血清脂肪酶活性,降低血清总胆固醇和甘油三酯含量,显著降低腹脂率(P<0.05);4)YSK可明显减少空肠和直肠中的大肠杆菌,增加乳酸杆菌数量,降低肠道pH(P<0.05),降低死亡率;5)YSK对肉仔鸡营养代谢和免疫调控的机理为:YSK有益微生物通过分泌消化酶和酸化作用提高消化酶活性来提高饲料营养的吸收利用率,并产生B族维生素、有机酸和其他活性物质提高肉仔鸡的生产性能和生长速度;通过刺激免疫器官发育、提高抗体水平和淋巴细胞活力以及优化肠道菌群结构(乳酸杆菌增加,大肠杆菌减少)提高肉仔鸡的抗病力。 |
| 关键词: 微生物饲料添加剂 益生康 肉仔鸡 细胞免疫 体液免疫 营养代谢 调控机理 |
| DOI：10.11841/j.issn.1007-4333.2005.03.067 |
| 修订日期：2004-12-06 |
| 基金项目:国家高技术研究发展计划项目(8190712)，国家“跨越计划”资助中试产业化项目(2001跨16) |
|
| Modulating mechanism of YISHENGKANG as feed additives on nutrient metabolism and immune function in broiler chickens |
|
|
|
| Abstract: |
| YISHENGKANG (YSK) is a microbial feed additive. A broiler feeding trial was conducted to test the mechanism of YSK in modulating nutrient metabolism and immune function in broiler chickens. The optimum dosage in feed was also studied. Five groups each having 200 broiler chickens were fed with basal diet added with 0, 005%, 01%, 02% YSK and 10mg/kg flavomycin. At 7d and 14d, 05mL beef serum of 5g/L albumin were injected into chicken shin as antigen. The results showed that optimal quantity of YSK was 01%. Comparing with flavomycin, YSK had better effects on promoting chicken growth and enhancing feed efficiency. The growth of thymus gland, spleen and the bursa of Fabricius were all stimulated by YSK. It was found that adding YSK resulted in activity increases of the chicken's T and B lymphocyte, globulin content and antibody level of the serum. YSK could increase the contents of total protein and the globulin in serum through regulating both protein fat metabolisms. The serum lipase activity increased, but the total cholesterol in serum and triglyceride content decreased due to adding YSK. YSK showed significant effects in modulating fat metabolism and lowering down abdominal fat rate (P<005). YSK could obviously depress E. coli, increase Lactobacillus quantity in the jejunum and the rectum, and lower the pH value of chicken gut (P<005). The mechanism of YSK in modulating nutrients metabolism and immune function was included as followings. 1. Some digestive enzymes and acids produced by the microorganisms in YSK could be benefit to both absorption and transformation of the feedstuff2. The microorganisms in YSK might produce vitamin B groups, organic acid and other active materials which enhanced productive performance and growth rate3. YSK might stimulate immune development and adjust gut microfloras. The chicken thus had higher ability against diseases. |
| Key words: microbial feed additive,Yishengkang,broiler chicken,cellular immunity,humoral immunity,nutrient metabolism,modulating mechanism |
