中草药与金霉素对生长猪的影响及其机理初探

75～80日龄体重相近仔猪150头，随机均分3组，每组5个重复，每个重复10只样本，研究中草药饲料添加剂与金霉素影响生长猪生产性能的免疫内分泌机制。以中草药添加剂（1％）和盒霉素（25mg／kg）分别添加饲喂组Ⅰ，Ⅱ猪群，组Ⅲ为对照，各组仔猪注射猪瘟疫苗2头份／头。分别于开始用药当天（d0）、35d（d35）时逐一称重，并各组前腔静脉采血10头，统计各组猪群生产性能，测定血清猪瘟抗体水平和胰岛素样生长因子-Ⅰ（IGF—Ⅰ）、胰岛素（Insulin）和三碘甲腺原氨酸（T3）和甲状腺素（T4）等与生长有关的内分泌激素。结果显示中草药组仔猪在净增重、日增重和增重率及料肉比方面都显著优于金霉素组和对照组猪群，而后2组间差异不显著。试验结束时，中药组猪群血清猪瘟抗体水平、IGF—Ⅰ、Insulin和T4水平显著高于金霉素组和对照组仔猪。表明该中草药添加刑可通过增强仔猪免疫功能．并显著提高仔猪血清IGF—Ⅰ和胰岛素的水平、减缓T4的下降，从而提高仔猪的生产性能，表现出1种整体调节效应。

EFFECTS OF A CHINESE HERB FEED ADDITIVE AND CHLORTETRACYCLINE ON THE GROWTH OF GROWING PIGLETS AND THEIR MECHANISM

One hundred and fifty piglets with similar body weight were divided at random into three groups.A Chinese herb feed additive at 1% was administered to Group I, chlortetracycline at 25 mg/kg to Group II,and Group III was used as the control.All the piglets were injected with swine fever vaccine at double dosage and stabled in similar environments.Blood samples were obtained via prosocoel vein.Serum hormones related to growth,namely,insulin-like growth factor-I(IGF-I), insulin and hormones of the thyroid gland(3,5,(3')-tetraiodothyronine,T_3; 3,5,3'5'-tetraodothyronine,T_4) and specific antibody in the piglets were quantified by radioimmunoassay and positive hemopexis test.The results showed that Group I showed a better performance in respect of body weight gain,live weight gain per pig per day,rate of body weight gain and feed conversion rate than Groups II and III.No significant difference was observed between Group II and Group III in the above listed indexes.As determined at the end of the experiment, Group I excelled Groups II and III in respect of the levels of specific antibody,IGF-I,insulin and T_4 in the serum of the animals.Therefore,the Chinese herb feed additive improved the overall performance of the growing pigs by stimulating the function of the immunity network,enhancing the values of IGF-I and insulin and retarding the decline of T_4 in the serum of the pigs.