6Wise D R. Nutrition -Disease interaction of leg weakness in poultry[A]. In:Recent Development in Poultry Nutrition[M], Essex: Anchor Press, 1989.303-319.
7Drs S V Rama Rao, M V L N Raju, R P Sharma, et al. Lameness in chickens: alliviation by dietary manipulation[J]. Poultry International, 2003, 42 (9) : 56- 61.
8Classen H L. Photoperiod effects on performance and leg abnormalities in broiler chickens[J]. Poultry Science, 1989, 68: 873-880.
9Bruce Boren. Nutritional aspects of leg weakness[J]. Poultry International, 1992, 31 (13) : 24-33.
10Haye V & Simons P C M. Twisted legs in broiler[J]. British Poultry Science, 1978, 19: 549-557.