淀粉补饲引起的组合效应对湖羊生长性能和血液生化指标的影响

选用36头3.5月龄的生长期湖羊,根据体重分为4组,以稻草为粗饲料,以等量菜籽粕为蛋白补充料,以玉米淀粉为能量补充料,研究淀粉补饲引起的组合效应对湖羊生长性能和血液生化指标的影响,并探讨组合效应在代谢层次的产生机理。结果表明:淀粉补饲,显著提高了湖羊日增重(P<0.05),但日增重不随淀粉的增加而线性升高,过多的淀粉不会带来额外增重;淀粉补饲显著降低血中的尿素氮浓度(P<0.05),提高血糖水平(P<0.05)。上述结果显示,对于生长期的反刍动物,在日粮等氮的情况下,适当的能量补饲会对生长性能产生正组合效应,但过多的能量补饲将会产生负效应;提高日粮的能量水平可以促进机体蛋白质的利用效率和沉积,这可能是能量在机体代谢层次发挥正组合效应的主要机理。

Effects of Associative Effect Caused by Starch Supplementation on Growth and Blood Biochemical Indexes of Hu Lambs

Thirty-six male Hu lambs were divided into four equal groups according to body weight,fed with rice straw ad libitum,equal amount of rapeseed meal,and supplemented with different level of cornstarch to study the associative effects caused by starch supplementation on growth,feed intake and blood biochemical indexes of Hu lambs,and tried to probe into the mechanism of associative effects on metabolic level.Rice straw intake was not affected by supplemental cornstarch,while growth performance was significantly increased(P < 0.05),the average daily gain of body weight was not increased linearly with supplemental starch,overfeeding of starch showed no additional weight gain.Blood total protein and triglyceride were not affected by cornstarch,while urea nitrogen was significantly decreased(P < 0.05),indicating higher efficiency of protein utilization with supplemental cornstarch.Blood glucose was increased significantly by supplemental cornstarch(P < 0.05).These results suggested that,for growing animal consuming equal level of protein,proper energy supplementation will show positive associative effect on growth,while overfeed of energy will show negative effect.Increment in energy will improve the efficiency of protein utilization and deposition,and this might be the main mechanism of positive effect at metabolic level resulting from energy supply.