EFFECTS OF HOUSING CONDITIONS ON HEALTH AND WELFARE OF CAGED LAYING HENS

摘要

China is a country with great amount of livestock and poultry rearing. With the development of Chinese intensive animal husbandry during the decades, and the concern about animal welfare from the worldwide, the health and welfare conditions of our livestock and poultry have attracted the attention of people. Now cage system is still the main rearing mode of laying birds in our country, the purpose of the study is to investigate the effects of different housing conditions on health and welfare of caged layers under commercial conditions. Three commercial layer farms of Yanqing District, Beijing were chosen (total layer number is 534,500), and the health and welfare conditions of caged layers were subsequently assessed. Among the three commercial layer farms, two of which adopted the way of ladder-cage with three tiers, and another one adopted the way of cascade-cage with eight tiers, the stocking density are 411 cm~2, 420 cm~2, 450 cm~2, respectively. There are differences among housing construction, facility and establishment, feed and management, environmental conditions, etc. We measured wind speed, maximum wind gust, average wind speed, temperature, wind chill, relative humidity, heat stress; measured NH_3, CO_2, and H_2S concentration in the air; and recorded laying performance., mortality and abnormal behavior of caged layers. The result shows that great differences among the 3 housing conditions the farmers provided for caged layers have greater effects on health and welfare of layers thanthe stocking density and cage way themselves.