3Adams A W,Craig J V. Effect of crowding and cage shape on productivity and profitability of caged layers:A survey [J]. Poult Sci, 2985,64(2) :238-242.
4Glatz P C,Barnett J I. Effects of perches and solid sides on production,plumage and foot condition of laying hens in conventional cages in a naturally ventilated shed [J]. Aust J Agrie Res, 1996,36(3) :269-275.
5Tauson R. Furnished cages-pros and cons [A]. Proceedings poultry information exchange [C]. Department of Primary Industries, 2000.
6Craig J,Adams A. Behaviour and well-being of hens(Gallus Domesticus)in alternative housing environments [J]. World's Poult Sci, 1984,40:221-240.
7Tauson R. Avoiding excessive growth of claws in caged laying hens [J ]. Acta Agrie Seandinaviea, 1986,36 ( 1 ) : 95-106.
8Meneh J A,Tienhoven A V. Effects of cage and floor pen management on behaviour,production,and physiological stress responses of laying hens [J ]. Poult Sei, 1986,65 (6) : 1058-1069.
9Koelkebeek K W,Amoss M J. Production, physiological,and behavioural responses of laying hens in different managementenvironments[J ]. Pouh Sei, 1987,66 : 397-407.
10Gregory N C,Wilkins I J,Kestin S C,et alEffects of husbandry system on broken bones and bone strength in hens[J]. Vet Record, 1990,128(17 ) :397.