太行鸡、海兰灰蛋鸡生长期消化道主要酶系变化规律比较

Comparison of Main Digestive Enzymes between Taihang Layer and Hy-Line Layer in Growth Period

以1日龄的太行鸡和海兰灰蛋鸡为对象,测试第5、9、14、21、28、35、42、49、56、63、77、91天十二指肠和空肠内的淀粉酶、脂肪酶、胰蛋白酶及盲肠内的纤维素酶活性,探讨太行鸡与海兰灰蛋鸡营养物质利用率差异的原因以及消化道酶的变化规律。结果表明,太行鸡粗脂肪、粗蛋白、Ca、P等营养物质消化率分别比海兰灰蛋鸡低2.50%、8.99%、8.40%和10.90%。太行鸡和海兰灰蛋鸡消化道酶的发育规律基本一致,消化道内各酶随日龄增长逐渐增加,达到峰值后趋于稳定。但各酶活性达到峰值的时间不同。太行鸡和海兰灰蛋鸡十二指肠淀粉酶、脂肪酶、胰蛋白酶活性达到峰值的时间分别为第35、35、42天和第35、35、42天,空肠则分别为第21、35、35天和第28、35、35天;盲肠内纤维素酶活性达峰值时间为第49、56天。太行鸡十二指肠和空肠淀粉酶、脂肪酶活性均比海兰灰蛋鸡低,胰蛋白酶活性比海兰灰蛋鸡高,盲肠纤维素酶活性比海兰灰蛋鸡高。太行鸡、海兰灰蛋鸡空肠内淀粉酶、脂肪酯和胰蛋白酶活性比十二指肠内相应的酶高。

120 1-day-old Taihang layers and 120 1-day-old Hy Line layers were randomly allocated two groups for four replicates with 30 each. On 5, 9, 14, 21, 28, 35, 42, 49, 56, 63, 77 and 91 d, activi- ties of amylase, lipase, trypsin and cellulase in intestinal contents were measured. The results were as follows： （i） By contrast with Hy-Line layer, digestibility of fat, crude protein, Ca and P in Taihang layer decreased by 2. 50%, 8. 99%, 8.40% and 10. 90%, respectively; （ii） Activities of digestive enzymes in intestinal contents in Taihang layer and Hy-Line layer increased with age. In Taihang and Hy-Line layers, duodenum maximal values were attained on 35 d for amylase, 35 d for lipase, and 42 d for trypsin. In Taihang layers, jejunum maximal were attained on day 21 d for amylase, 35 d for lipase, and 35 d for trypsin, In Hy-Line layers, jejunum maximal were attained on 28 d for amylase, 35 d for lipase, and 35 d for trypsin. In Taihang and Hy Line layers,Caecum maximal were attained on 49 d and 56 d for cellulose respectively; （iii） As to layer breed, Taihang layer had a lower activities of amylase and lipase in duodenum and jejunum, but had a higher activities of cellulose in cecum; （iv） As to intestinal , activities of amylase, lipase and trypsin in Taihang and Hy-Line layer jejunum were 9.2, 5.3, 2.0 folder and 8.2, 5.3, 2.0-folder greater than that in duodenum, respectively.