Welfare of layers housed in small furnished cages on Danish commercial farms: the condition of keel bone,feet, plumage and skin

1. An on-farm assessment of keel bone, feet, plumage and skin damage was conducted in layers in small furnished cages to evaluate welfare implications.

2. Thirteen farms participated, all housing Lohmann LSL layers in systems allowing 8 or 10 hens per cage.

3. Each flock was visited at three different ages: 32, 62 and 77 weeks. During each visit, 100 hens were examined for keel bone fractures and deviations, plumage damage, body wounds, foot pad lesions, bumble feet, missing toes and toe wounds.

4. A deterioration with age of the condition of the plumage and keel bone was found (P < 0.001). At 77 weeks of age, 16% of the birds had poor plumage, and 43% of the birds had keel bone damage. In contrast, foot pad lesions were most prevalent at 32 weeks of age (13%), whereas the other foot injuries and body wounds remained at a relatively low level throughout the three ages examined.

5. Prevention of damage to the keel bone, plumage and foot pads should therefore be considered when aiming to improve welfare of laying hens housed in small furnished cages.     

小型远洋渔船外龙骨的研究

渔船在海上的安全与舒适性越来越被重视。研究了小型远洋鱿钓渔船外龙骨的结构形式,结合特定航行区域的波浪散布图,采用三维势流理论对有外龙骨的渔船进行船体运动响应计算,并与无外龙骨时的船体运动响应进行比较,为外龙骨的设计与应用提供合理的依据。