日粮不同蛋白质水平对绵羊IGF-1和GH分泌及基因表达的影响

Effects of Different Dietary Protein Levels on the Secretion and mRNA Expression of IGF-1 and GH in Sheep

本研究旨在探讨不同蛋白质水平日粮对绵羊胰岛素样生长因子-1(IGF-1)和生长激素(GH)分泌及基因mRNA表达量的影响,为科学配置肉羊饲料及研究肉羊生长发育提供基础。选择6月龄体重相近的多胎萨福克公羔18只,随机分为3组,分别饲喂不同蛋白质水平的日粮(低蛋白日粮、中蛋白日粮和高蛋白日粮)。采用ELISA方法和SYBR Green Real-time PCR方法检测日粮不同蛋白质水平对不同生长发育阶段(30、60、90和120d)羔羊外周血中IGF-1、GH浓度和皮肤组织中基因表达的影响。结果显示,日粮蛋白质水平显著影响绵羊平均日增重、外周血中IGF-1和GH的浓度以及皮肤组织IGF-1基因的表达丰度,而未显著影响GH基因的表达丰度。结果提示,随着日粮蛋白质水平的升高,绵羊生长发育快,外周血中IGF-1浓度增加,GH浓度降低,IGF-1基因表达量增加。

The objective of this study was to discuss the effects of different dietary protein levels on insulin-like growth factor-1(IGF-1)and growth hormone(GH)secretion and mRNA expression in sheep,to provide a theoretical basis for scientific preparation of feed and study the growth in sheep.Eighteen 6-month-old prolific Suffolk rams were randomly allocated into 3treatments with different dietary protein levels(low protein,medium protein and high protein).The concentrations in peripheral blood and mRNA expression levels in skin of IGF-1and GH were detected at different growth stages(30,60,90 and 120d)with different dietary protein levels by ELISA and SYBR Green Real-time PCR methods.The results showed that the average daily gain,the concentrations of IGF-1and GH in peripheral blood,the mRNA expression of IGF-1in skin were significantly affected by dietary protein levels.However,mRNA expression of GH gene did not change significantly.With the increased protein intake,the growth of sheep was faster,the con-centration of IGF-1was increased,but the concentration of GH was decreased in peripheral blood,mRNA expression of IGF-1gene was up-regulated.