【作者】 邹晓娟；

【导师】 沈赞明；

【作者基本信息】 南京农业大学 ， 基础兽医学， 2010， 硕士

【摘要】 一、饲喂半胱胺制剂对新生母犊牛断奶成功率和生长指标的影响本试验在南京卫岗乳业集团有限公司卫岗生态牧场进行。选用8日龄荷斯坦母犊牛36头,按照体重相近的原则随机分为对照组(n=18,BW=37.68±0.88kg)和试验组(n=18,BW=37.59±0.86kg),研究半胱胺对犊牛早期断奶的影响,试验期自8日龄至50日龄。犊牛的饲喂和管理按照牧场方案,在此基础上试验组饲喂半胱胺盐酸盐(CT2000) 60mg/kg·BW·d。两组犊牛均于45日龄开始断奶,最终于50日龄完成断奶。结果显示,饲喂半胱胺的犊牛的日增重和断奶时的体高、胸围等指标与对照组相比没有明显变化,但断奶成功率达到100%,比对照组高出17%。表明,饲喂半胱胺对犊牛成功早期断奶有促进作用。二、半胱胺对早期断奶犊牛免疫功能和血清胰岛素的影响试验一饲喂半胱胺制剂对母犊牛早期断奶淋巴细胞转化率及血清中白细胞介素-2 (Interleukin-2, IL-2)、谷胱甘肽(Glutathione, GSH)和胰岛素(Insulin)的影响分别于28日龄、45日龄和50日龄(断奶时)采血,测定血清中IL-2、GSH和Insulin水平,并在50日龄时采血做淋巴细胞转化试验。结果显示,饲喂半胱胺的犊牛淋巴细胞转化率(50日龄)显著高于对照组(P<0.05)；45日龄时,血清IL-2和Insulin水平显著高于对照组(P<0.05)；血清GSH水平(50日龄),显著高于对照组(P<0.05)。研究表明,饲喂半胱胺制剂改善了犊牛断奶阶段的免疫功能,增强了机体抗氧化功能,对机体能量代谢水平有一定影响,上述结果可能与犊牛早期断奶成功率的提高有关。试验二半胱胺促进新生犊牛T淋巴细胞增殖和抗氧化功能的体外研究1)采集5头新生荷斯坦公犊牛和4头45日龄荷斯坦母犊牛新鲜血液,分离淋巴细胞进行培养。试验组添加半胱胺(终浓度为0.5 mM)培养72小时,测定淋巴细胞转化率。结果显示,与对照组相比,半胱胺处理分别提高了新生犊牛(P<0.05)和45日龄犊牛(P<0.05)T淋巴细胞转化率；2)采集4头45日龄荷斯坦母犊牛新鲜血液,分离淋巴细胞进行培养。试验组添加半胱胺(终浓度为0.5 mM)培养72小时,测定T淋巴细胞胞内GSH含量,结果显示胞内GSH含量显著升高(P<0.04)；3)采集4头45日龄荷斯坦母犊牛新鲜血液,分离淋巴细胞进行培养。试验组添加IGF-1(终浓度为25ng/mL)或Insulin(终浓度为60 ng/mL)进行处理,培养72小时后测定淋巴细胞转化率。结果显示,IGF-1显著提高了T淋巴细胞转化率(P<0.05)；Insulin对淋巴细胞增殖有一定影响。研究表明,半胱胺可以直接刺激犊牛外周血T淋巴细胞增殖,半胱胺对新生犊牛T淋巴细胞有同样的促增殖作用；半胱胺还可通过增加胞内GSH含量,促进T淋巴细胞增殖；也可通过IGF-1或Insulin介导对淋巴细胞的增殖作用。上述结果表明,饲喂半胱胺可提高犊牛早期断奶的断奶成功率,半胱胺提高犊牛早期断奶成功率与其增强犊牛免疫功能有关。更多还原

【Abstract】 1 The effect of feeding cysteamine on the successful weaning rate and growth parameters of calvesThe experiment was conducted in Nanjing Weigang campus diary farm.36 Holstein calves were allotted, based on age and body weight, to control(n=18, BW= 37.68±0.88kg) and experiment (n=18, BW=37.59±0.86kg) groups randomly. Both groups were fed according to the strategy of dairy farm, with the experiment group supplemented by CT2000 (60mg/kg·BW·d). The experiment was actualized from 8-day to 50-day old of the calves. The calves were weaned at 45-day old and the weaning process finished at 50-day old. The results showed that there were no differences between two groups in dairy body weight neither the body size. But the rate of successful weaning of experiment group was 100%, which is 17% higher than the control group. This predicted that the cysteamine had positive effect on the early weaning of calves.2 The effect of feeding cysteamine on the immune abilities and concentration of serum Insulin of calvesExperiment 1:The effect of feeding cysteamine on transformation of peripheral blood lymphocytes and concentrations of serum IL-2、Glutathione and Insulin in pre- and post- weaning calvesBlood samples were taken from calves at 28-day old,45-day old and 50-day old. We tested the concentration of IL-2、GSH and Insulin in serum. Transformation of peripheral blood lymphocytes was tested at 50-day old. The rate of transformation of peripheral in 50-day old calves was significantly enhanced in experiment group(P<0.05); the concentration of serum IL-2 and Insulin in 45-day old calves was remarkably higher in experiment group(P<0.05); the concentration of serum GSH was evidently increased in experiment group(P<0.05), too. The results indicated that feeding cysteamine improved the immune abilities and antioxidative capability of calves to elevate the successful weaning rate. Meanwhile, the energy metabolism of calves was also affected by feeding cysteamine.Experiment 2:In vitro study on the positive effect of cysteamine on the transformation of peripheral blood lymphocytes and antioxidative capability in neonatal calves1) In vitro, lymphocytes were separated from the peripheral blood in five newborn male Holstein calves and four 45-day female Holstein calves. The experiment wells were treated with cysteamine (at the concentration of 0.5 mM). The transformation of lymphocytes was tested after 72h. The result showed that the transformation of T lymphocytes was significantly increased (P<0.05).2) In vitro, we separated lymphocytes from four 45-day female Holstein calves. The experimental wells were treated with cysteamine (at the concentration of 0.5 mM), the intracellular GSH of T lymphocytes was detected after 72h. We founded that the concentration of intracellular GSH in experimental groups was observably hoisted (P<0.05).3) In vitro, we separated lymphocytes from four 45-day female Holstein calves. The experimental wells were treated with IGF-1 (at the concentration of 25 ng/mL) or Insulin (at the concentration of 60 ng/mL). The transformation of lymphocytes was tested after 72h. The result showed that the transformation of T lymphocytes was significantly increased (P<0.05) in the experiment groups.This study illuminated that cysteamine stimulate the proliferation of peripheral blood lymphocytes directly in calves, so does in the newborn calves in vitro; or exert its function indirectly via IGF-1 or Insulin and by increasing intracellular GSH in lymphocytes.In conclusion, feeding cysteamine could improve the successful early weaning of calves. The mechanism was relative to the improvement of immune ability in calves.更多还原