中文摘要：

本试验对21、42和56日龄的2个品种肉鸡胰腺、十二指肠和空肠前段食糜脂肪酶活性及回肠末端食糜粗脂肪表观消化率进行了测定和比较。以AA肉鸡和北京油鸡为试验动物，将不同日龄的每个品种肉鸡随机分为3组，每组4个重复，每个重复8只鸡。分别于21、42和56日龄宰杀每个重复5只体重相近的肉鸡，获取的胰腺、十二指肠、空肠前段和回肠末端食糜分别用于测定脂肪酶活性和粗脂肪表观消化率。结果表明：AA肉鸡胰腺脂肪酶活性在42日龄时达到最高，从42到56日龄开始逐渐降低；小肠食糜脂肪酶活性21日龄极显著高于42和56日龄（P〈0．01），粗脂肪表观消化率与胰腺脂肪酶活性变化趋势相同。北京油鸡56日龄胰腺脂肪酶活性最高，小肠食糜脂肪酶活性42和56日龄低于21日龄，但3个日龄间粗脂肪消化率差异不显著（P〉0．05）。整个试验期间，3个相应日龄北京油鸡小肠食糜脂肪酶活性高于AA肉鸡，其中21和56日龄时差异显著（P〈0．05），粗脂肪消化率同样高于AA肉鸡，但只有56日龄时差异显著（P〈0．05）。

英文摘要：

To compare pancreas and intestinal chyme lipase activities, crude fat digestibility between Arbor Acres （AA） broil ers and Beijing fatty chickens at 21, 42 and 56 days of age, 96 birds for each broiler breed were randomly allotted to 3 groups with 4 replicates of 8 birds per replicate. Five birds from each replicate were killed and sample were taken at 1, 42 and 56 days of age. Lipase activities and crude fat digestibility were determined. The results showed that pancreas lipase activities of AA broilers achieved maximum at 42 days of age, and then from 42 to 56 days of age, gradually decreased. Lipase activities in intestinal chyme at 21 days of age were higher than those at 42 and 56 days of age（P〈0.01）. The crude fat digestibility changed following the same trend of pancreas lipase activity. Pancreas lipase activities of Beijing fatty chickens achieved maximum at 56 days of age. Lipase activities in intestinal chyme at 42 and 56 days of age were lower than those at 21 days of age. However, crude fat digestibility was not different at different days of age （P〉0.05）. During this experiment, lipase activities in intestinal chyme of Beijing fatty chickens were higher than those of AA broilers at each day of age, but at 21 and 56 days of age were significantly higher （P〈0.05）. Crude fat digestibility of Beijing fatty chickens was also higher than those of AA broilers, but only at 56 days of age was higher significantly （P〈0.05）.