【摘要】 罗斯鸡受精蛋９００枚孵化至第１３ｄ时随机分为３组。第１组为正常对照组，孵化过程中不作任何处理；第２组在孵化第１３ｄ向气室内注射甲状腺激素（Ｔ＿４）；第３组向气室内注射硫尿嘧啶。分别测定孵化第１７ｄ、第１９ｄ及１、５、１０、１５、２０日龄小鸡的腺胃、十二指肠与胰腺匀浆消化酶的活性，检查啄壳迟早、孵化率与雏鸡卵黄囊吸收情况。结果表明：鸡胚胎后期淀粉酶活性增加很快，出生后２０ｄ内随日龄增加酶活性仍有少量增加。胚胎后期至５日龄前鸡脂肪酶活性增加较快，１５日龄后活性不再增加。胚胎后期至２０日龄间鸡胃蛋白酶活性随日龄而逐渐增加。胚胎后期至１０日龄鸡胰蛋白酶活性逐渐增加，１０日龄后酶活性不再增加。甲状腺素与硫尿嘧啶处理鸡胚对小鸡消化道酶活性无显著影响（Ｐ＞０．０５）。甲状腺素处理使鸡啄壳延迟、孵化率降低（Ｐ＜０．０５），雏鸡对卵黄囊内的卵黄的吸收显著减慢（Ｐ＜０．０５），一直到１５日龄３０．２％处理鸡仍有０．４～３．８９卵黄尚未吸收。硫尿嘧啶处理对鸡的孵化性能和对卵黄囊吸收无显著影响。更多还原

【Abstract】 Experiments were conducted with fertile chicken eggs to determine the effects ofthyroxine and thiouracil on chicken digestive enzyme activity,hatchability and yolk-absorption. On the l3th day of incubation, 900 eggs were randomly divided into threegroups.Eggs in group I(control) were hatched with Out any treatment.Eggs in groupⅡ,were injected with thyroxine(200ng per egg)in the air cells,while eggs in groupⅢwere injected with thiouracil(200μg per egg).Amylase activity increased during thelater embryo stage,but increased only slightly when the chicks were 1 to 20 days ofage。Lipase activity increased quickly starting from the later embryo stage to about 5days of age,with a slower increase after l0 days of age. Pepsin activity increasedgradually from the embryo stage to 20 days of age. Trypsin activity increased startingfrom the later embryo stage to l0 days of age, but did not increase thereafter.Thyro-xine and thiouracil treatment did not significantly affect digestive enzyme activity.However,injection of T4 on the l3th daY of incubation significantly(P<0.05) postpo-ned the pipping and depressed hatchability,and also significantly(P<0.05) postponedthe absorption of the yolk sac after hatching.At l5 days of age, 30.2%of the chickstreated with T4 still had yolk sacs ranging in size from 0.4 to 3.8g.Injection ofthiouracil on the l3th day of incubation had no significant effect on hatchability andyolk absorption in embryos or chicks.更多还原