不同锌源对猪早期生长及其相关基因表达的影响

利用不同的锌源饲喂早期断奶仔猪，研究其对仔猪早期生长的影响，并从激素水平及基因表达上探讨其可能的作用机制。选取28d断奶的猪45头，随机分为3组，每组设3个重复，每重复5头，对照组饲喂基础日粮（含锌101mg／kg），另外2组分别添加硫酸锌组（ZnSO4）、蛋氨酸锌组（Zn—Met）使日粮含锌240mg／kg。结果表明：日粮中添加不同形式的锌，均能显著提高仔猪日增重和胰岛素生长因子-Ⅰ（IGF—Ⅰ）基因表达量（P〈0．05），蛋氨酸锌组IGF—ⅠmRNA表达量显著高于硫酸锌组（P〈0．05）；而对猪血浆生长激素（GH）水平及其生长激素受体（GHR）表达影响均不显著。表明添加锌可以通过IGF—Ⅰ对生长的调控作用而影响机体生长发育。

Effect of Different Zinc Sources on Early Performance and Correlative Gene Express of Piglet

To estimate effect of different zinc sources on early performance and correlative gene express of piglet,forty-five 28-day-old weaned piglets were randomly divided into three groups of 15 each. The control was fed on corn-soybean basal diet at 101 mg/kg zinc. Treatments of ZnSO4 and Zn-Met were supplemented with zinc sulfate and zinc-methionine at 240 mg/kg zinc. The results showed that the both forms of zinc had no effect on GH concentration and the expression of GHR mRNA ( P >0.05),while they significantly up-regulated the expression of IGF-I mRNA and the weight gain. As compared to ZnSO4,Zn-Met significantly increased and the level of IGF-I mRNA expression ( P <0.05). It was therefore concluded that supplementing zinc in basal diet could enhance weight gain by regulation of IGF-I.