2Vucemilo M,Matkovic K,Vinkovic B,et al.Effect of microclimate on the airborne dust and endotoxin concentration in a broiler house[J].Journal of Animal Science,2008,53(2):83-89.
4Meluzzi A,Fabbri C,Folegatti E,et al.Survey of chicken rearing conditions in Italy:effects of litter quality and stocking density on productivity,foot dermatitis and carcase injuries[J].British Poultry Science,2008,49(3):257-64.
5Dawkins M S,Donnelly C A,Jones T A.Chicken welfare is influenced more by housing conditions than by stocking density[J].Nature,2004,427 (6972):342-4.
2Appleby M C,Hughes B O,Elson H A. Poultry production systems : behaviour, management and welfare [ M ]. Wallingford : CAB International, 1992,238.
3Webster A J F. Meat and right, farming as if the animals mattered[J]. Canadian Veterinary Journal,1987,28:462-466.
4Savory C J,Maros K,Rutter S M. Assessment of hunger in growing broiler breeders in relation to a commercial restricted feeding programme [J]. Anim Welf, 1993,2 : 131-152.
5Dillman D A. Mail and intemet surveys:the tailored design method[M].2^nd ed,New York:John Wiley & Sons,Inc,2000.
6Babbie E. Survey Research methods [M]. 2^nd ed. Belmont: Wadsworth Publishing, 1990.
7Hocking P M. Assessment of the effects of separate sex feeding on the welfare and productivity of broiler breeder females[J] British Poultry Science, 1990,31:457-463.
8Hocking P M. Assessment of the welfare of food restricted male broiler breeder poultry with musculoskeletal disease[J]. Res Vet Sci, 1994,57:28-34.
9Hocking P M. Welfare of broiler breeder[C]. Proceedings of the WPSA Spring Meeting,1999,24-25,18-23.
10Hocking P M,Maxwell M H,Mitchell M A. Welfare assessment of broiler breeder and layer females subjected to food restrict-ion and limited acess to water during rearing [J]. Br Poult Sci, 1993,34:443-458.
8BrambeI1 F W R. Report of the Technical Committee to En quire into the Welfare of Animals kept under Intensive Hus bandry Systems[M]. London Command 2836. HMSO,1965 13.
9Dawkins M. From an animal's point of view motivation, fit- ness, and animal welfare[J]. Behav Brain Sci, 1990,13: 1-61.
10Broom D. Animal welfare defined in terms of attempts to cope with the environment [J]. Acta Agric Scand Supl, 1996,27: 22-28.