Mashaly M M, Webb M L, Youtz S L, Roush W B, Graves H B
Poult Sci. 1984 Nov;63(11):2271-4. doi: 10.3382/ps.0632271.
The response of adrenal glands of Single Comb White Leghorn laying hens housed under different population densities was studied. The birds were reared in floor pens until they were 19 weeks of age, after which they were housed in cages. Cage size was 30.5 X 50.8 cm. Three, four, or five birds were housed per cage. Corticosterone concentrations were measured in all birds 48 and 96 hr following housing in cages and weekly thereafter for 6 weeks. Corticosterone concentrations were consistently higher in the serum of birds housed five per cage than in birds housed three or four per cage. It was concluded that in order to minimize physiological stress in cage layers, more than 387 cm2 per bird should be considered.
研究了单冠白来航蛋鸡在不同饲养密度下肾上腺的反应。这些鸡在地面围栏中饲养至19周龄，之后转入笼中。笼的尺寸为30.5×50.8厘米。每个笼子饲养三只、四只或五只鸡。在转入笼中48小时和96小时后，以及此后每周持续6周，对所有鸡的皮质酮浓度进行测量。每笼饲养五只鸡的血清皮质酮浓度始终高于每笼饲养三只或四只鸡的血清皮质酮浓度。得出的结论是，为了使笼养蛋鸡的生理应激最小化，每只鸡应考虑超过387平方厘米的空间。
