日粮赖氨酸对70~90日龄肉兔生长性能、血清IGF-Ⅰ浓度及其基因表达的影响

Effects of Dietary Lysine on Growth Performance,Serum Insulin-like Growth Factor-Ⅰ(IGF-Ⅰ) Concentration and IGF-Ⅰ mRNA Expression in Meat Rabbits from 70 to 90 days of Age

为研究玉米-豆粕型日粮中赖氨酸水平对70~90日龄生长肉兔生产性能、血清类胰岛素生长激素浓度及其基因表达的影响。选择100只体重接近、前期饲养相同的70日龄新西兰肉兔为试验动物,随机分成5组,以赖氨酸含量分别为0.55%、0.65%、0.75%、0.85%和0.95%的5种日粮为试验处理,进行为期20 d的饲养试验。结果表明,随日粮赖氨酸水平的增加,90日龄生长肉兔生长性能组间差异不显著（P〉0.05）;血清胰岛素、生长激素、类胰岛素生长激素浓度显著提高（P〈0.05）,分别在0.85%,0.75%和0.95%达到最大值;肝脏和肌肉IGF-Ⅰ相对表达量也明显增加（P〈0.05）。综上所述,70~90日龄生长肉兔血清IGF-Ⅰ浓度和基因表达受日粮赖氨酸水平的影响。

The experiment was conducted to study the effects of different amounts of dietary lysine on production performance,serum insulin-like growth factor-Ⅰ（IGF-Ⅰ） concentration and IGF-Ⅰ mRNA expression of growing rabbits.One hundred of 70 days New Zealand rabbits were allocated to individual cages and randomly divided into five groups.Five diets containing 0.55%,0.65%,0.75%,0.85% and 0.95% lysine respectively,were formulated as experimental treatments.The results suggested there was no significant difference in daily weight gain,feed/gain ratio（P0.05） with the increasing dietary lysine,however serum GH,IGF-Ⅰ and insulin（Ins） content increased significantly（P0.05） and reached the largest value under the lysine adding content of 0.85%,0.75% or 0.95% respectively.The IGF-Ⅰ relative expression level in the liver and muscle was up-regulated accompanying with the dietary lysine level increased.The present study suggested that the dietary lysine levels have significant effect in the IGF-Ⅰ expression and serum content.