断奶日龄对舍饲羔羊小肠内容物中主要消化酶活性的影响

为研究早期断奶日龄对羔羊小肠各段pH及主要消化酶活性的影响，选用55只初生重为（3.43±1.15）kg的甘肃现代肉羊育种群哺乳公羔，按同质原则分成3组，即对照组（正常吮乳组，25只）、Ⅰ组（28日龄断奶组，15只）和Ⅱ组（42日龄断奶组，15只）。在断奶12 h、7 d和14 d后从每个处理中随机抽取5只羔羊屠宰，测定小肠各段pH、α-淀粉酶、胰蛋白酶、糜蛋白酶和脂肪酶活性变化。结果显示，十二指肠食糜能够更为敏感地表达断奶对小肠pH及主要消化酶活性的影响。从小肠近端至远端，断奶对各肠段内容物pH及主要消化酶活性的影响逐渐减弱；断奶对小肠内容物pH、胰蛋白酶活性和脂肪酶活性影响较小；断奶日龄对羔羊小肠主要消化酶活性恢复所需要的时间影响不大，28日龄断奶组小肠α-淀粉酶活性恢复时间较42日龄断奶组短。本试验条件下，对羔羊实施28日龄断奶可行，且羔羊小肠主要消化酶活性恢复能力不逊于42日龄断奶羔羊。

Effect of Different Weaning Ages on Main Digestive Enzymes Activities in the Small Intestinal Contents of Lamb

The objective of this study was to determine the effects of different weaning ages on pH and the main digestive enzymes activities in the small intestinal contents of lamb. Fifty-five male lambs of Gansu modern breeding sheep group with(3.43±1.15)kg initial body weight were divided into 3 treatments randomly that were control group (sucking,25 lambs), group Ⅰ (weaning at 28 days old, 15 lambs), and group Ⅱ(weaning at 42 days old,15 lambs).5 lambs from each group were slaughtered at 12 h,7 d and 14 d after weaning,respectively,and the the change of pH and activities of α-amylase,trypsin,chympotrypsin and lipase were measured in the small intestinal contents. The results showed that the effects of pH and the main digestive enzymes activities could be expressed sensitively in the contents of duodenum. From duodenum to ileum,the effects of weaning turned weakening gradually,and it did not show a high-impact on pH,trypsin and lipase activities. There was no significant influence in the recovery time to the normal levels of the main digestive enzymes activities in the small intestinal contents by different weaning ages,the recovery time of α-amylase in group Ⅰ was shorter than group Ⅱ. In this trail condition,it was feasible to wean at 28 days of age,and it had no significant difference in the recovery ability of main digestive enzymes in the small intestinal contents weaning at 28 and 42 days old.