Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA.
Poult Sci. 2013 Aug;92(8):1972-80. doi: 10.3382/ps.2013-03008.
A major skeletal problem of conventionally caged hens is increased susceptibility to osteoporosis mainly due to lack of exercise. Osteoporosis is characterized by a progressive decrease in mineralized structural bone. Whereas considerable attention has been given to enriching laying cages, little research has been conducted on providing caged pullets with furnishments, in particular perches. The objective of the current study was to determine if metal perches during all or part of the life cycle of White Leghorns affected hen musculoskeletal health, especially at end of lay. Treatments during the pullet phase (hatch to 16.9 wk) entailed cages with and without perches. Four treatments were used during the laying phase (17 to 71 wk of age). Treatment 1 chickens never had access to perches at any point during their life cycle, typical of egg industry practices in the United States for conventional cages. Treatment 2 chickens had access to perches only during the egg-laying phase, which was from 17 to 71 wk of age. Treatment 3 chickens had access to perches only during the pullet phase (0 to 16.9 wk of age). Treatment 4 chickens had perch access throughout their entire life cycle (0 to 71 wk of age). Musculoskeletal health was assessed by measuring muscle weights, bone mineralization, bone fracture incidence, and keel bone deviations. Muscle deposition of 71-wk-old hens increased when given access to perches as pullets. Bone mineralization of 71-wk-old hens also increased if given perch access as adults. However, the disadvantage of the adult perch was the higher incidence of keel deviations and keel fractures at end of lay. The increase in bone mineralization of the keel bone as a result of perch access during the pullet and laying phases was not great enough to prevent a higher incidence of keel bone fractures at end of lay. Perch redesign and placement of perches within the cage to minimize keel fractures and deviations are possible solutions.
笼养蛋鸡的一个主要骨骼问题是易患骨质疏松症，主要是由于缺乏运动。骨质疏松症的特征是矿化结构骨逐渐减少。尽管人们对丰富产蛋鸡笼的环境给予了相当多的关注，但对笼养育成鸡提供铺料，特别是栖木的研究却很少。本研究的目的是确定在白来航鸡的整个生命周期或部分生命周期中使用金属栖木是否会影响母鸡的肌肉骨骼健康，特别是在产蛋后期。育成期（孵化至 16.9 周）的处理方法是在有栖木和没有栖木的笼子里进行。在产蛋期（17 至 71 周龄）使用了四种处理方法。处理 1 的鸡在其生命周期的任何时候都没有机会接触栖木，这是美国传统笼养蛋鸡行业的典型做法。处理 2 的鸡仅在产蛋期（17 至 71 周龄）才有机会接触栖木。处理 3 的鸡仅在育成期（0 至 16.9 周龄）才有机会接触栖木。处理 4 的鸡在整个生命周期（0 至 71 周龄）都有机会接触栖木。通过测量肌肉重量、骨矿化、骨骨折发生率和龙骨骨偏差来评估肌肉骨骼健康。作为育成鸡，如果允许接触栖木，71 周龄母鸡的肌肉沉积量会增加。如果成年后允许接触栖木，71 周龄母鸡的骨矿化也会增加。然而，成年栖木的缺点是在产蛋后期龙骨偏差和骨折的发生率更高。由于在育成期和产蛋期接触栖木，龙骨骨的骨矿化增加，但不足以防止产蛋后期龙骨骨骨折的发生率增加。对栖木进行重新设计和在笼内放置栖木以尽量减少龙骨骨折和偏差是可能的解决方案。
