Singh R P, Kumar J, Dwarkanath P K, Balaine D S
Br Poult Sci. 1983 Oct;24(4):477-82. doi: 10.1080/00071668308416764.
The housing system, age of pullets and their interaction had a significant effect on plasma 5'-nucleotidase and alkaline phosphatase activities. Activities were higher in birds in cages than in those on the floor, reflecting perhaps the stress of caging. Activities increased with age. Activities were higher in pullets selected for higher production. The type of housing had no effect on egg production, but age at first egg, egg weight and 40-week body weight were found to be affected significantly.
饲养系统、蛋鸡年龄及其相互作用对血浆5'-核苷酸酶和碱性磷酸酶活性有显著影响。笼养鸡的酶活性高于地面平养鸡，这可能反映了笼养带来的应激。酶活性随年龄增长而增加。高产蛋鸡品系的酶活性更高。饲养方式对产蛋量没有影响，但开产日龄、蛋重和40周龄体重受到显著影响。
