0～3周肉仔鸡消化道酶发育规律的研究

STUDIES ON DEVELOPMENT OF DIGESTIVE ENZYMES IN BROILER CHICKS

本试验以０～３周Ａｖａｉｎ商品代肉仔鸡公雏为研究对象，测试０，４，７，１０，１４，１７和２１日龄肉仔鸡体重，消化道器官重量，胰腺和肠道食糜中淀粉酶、胰蛋白酶、糜蛋白酶和脂肪酶活性的变化，基本摸清了０～３周肉仔鸡体重、消化器官的生长规律及消化道酶的发育规律。试验结果表明：（１）肉仔鸡在４～１０日龄日均相对生长率达到最大值（平均每天增重达１９％），１０日龄后下降，到１４～２１日龄，基本维持在１３％～１４％左右；（２）各器官的相对重量（ｇ／ｋｇ体重）达到峰值的时间并不一致，腺胃和肌胃的相对重量在４～７天为最高，肝和胰在７～１０天，小肠在７天左右；（３）从异速生长的指标看，肌胃的最大增长倍数是体重增长倍数的１．５倍，腺胃是２倍，肝脏是２．３倍，小肠是３倍，胰腺达６倍；（４）小肠内容物的相对重量（ｇ／ｋｇ体重）在４～１０日龄达到最大值，以后呈下降趋势；（５）胰腺和肠道的消化酶活性（活性单位／ｋｇ体重）基本上随着日龄的升高而上升。在胰腺，淀粉酶、胰蛋白酶、糜蛋白酶和脂肪酶活性均在１０，７，２１和１０日龄达到峰值。在肠道，淀粉酶、胰蛋白酶、糜蛋白酶和脂肪酶活性均在１０日龄达到峰值。从消化道酶的分泌情况看，肉仔鸡早期消化酶?

Avain male broiler chicks of 0～3 weeks were used as experimental animals.On day 0,4,7,10,14,17and 21,ten chicks were weighed and killed,respectilely,then the liver,pancreas,small intestine,gizzard,proventriculus,residual yolk and chyme in the small intestine were weighed,and the activities of amylase,lipase,trypsin and chymotrypsin were measured.The results were as follows:(1)Relative daily growth rate peaked at 4～10 d of age(19% gain/d)and then decreased gradually;at 14～21 d of age maintained in the range of 13%～14% gain/d.(2)Relative weight(g/kg body weight) of various organs peaked at different days.i.e.at 4～7 d for the proventriculus and gizzard,at 7～10 d for the liver and pancreas,7 d for the small intestine.(3)Maximal allometric growths,of the gizzard ,proventriculus,liver,small intestine and pancreas were 1.5,2,2.3,3 and 6-fold greater than that of the body.(4)Relative weight(g/kg body weight)of chyme in the small intestine peaked at 4～10 d of age and then decreased.(5)Activities(units/kg body weight)of the digestive enzyme measured in the pancreas and intestinal contents increased with age.In the pancreas maximal values were attained on day 10 for amylase on day, 7 for trypsin,on day 21 for chymotrypsin and on 10 for lipase.In the small intestine maxima were attained on day 10 for amylase,trypsin,chymotrypsin and lipase.