不同蛋白源对断奶大鼠生长性能和血液生化指标的影响

本研究旨在考察饲料蛋白品质与断奶大鼠生长性能和养分代谢之间的关系。选用80只清洁级SD雄性断奶大鼠,通过饲喂酪蛋白(CAS)、大豆分离蛋白(SPI)、玉米醇溶蛋白(ZEIN)为唯一蛋白源的半纯合日粮,研究不同蛋白源对机体产生的代谢效应。结果表明:相对于CAS组(对照组)而言,采食ZEIN具有较低的的养分消化率(P<0.05);血浆尿素氮显著升高(P<0.01);血浆胰岛素和类胰岛素生长因子水平分别低于和高于CAS对照组(P<0.05)。采食ZEIN引起血浆赖氨酸水平较CAS组显著降低(P<0.05),而亮氨酸水平显著升高(P<0.05)。试验表明,蛋白品质影响养分代谢的营养生理原因在于机体内分泌水平和体液氨基酸营养状态存在差异,从而引起大鼠生长性能发生相应变化。

Effects of Different Dietary Proteins on Growth Performance and Plasma Characters in Growing Rats

The aim of this study was to determine growth performance and plasma characters of growing rats induced by casein,soya protein isolate(SPI) and zein protein diets.Eighty male weaning Sprague-Dawley rats were divided to homogeneous four groupsbased on the average body weight in a completely randomized design to clarify different effects on metabolic responses caused by protein sources.Apparent and true nitrogen digestibility,protein efficiency ratio(PER),dry matter and energy digestibility were significantly lower in zein meal group compared to casein control group(P<0.05).Plasma concentration of PUN was increased(P<0.01)in zein-fed group.T However,the insulin was reduced but IGF-Ⅰ was elevated in plasma of growing rats when given zein meal(P<0.05).The Lys concentration in plasma was lower but Leu was much higher in zein-fed group(P<0.05).These results demonstrated that reasons for such metabolic responses induced by protein sources may be partly related to amino acid profiles in plasma and endocrine situation,resulting in different growth performance.