Knowles T G, Wilkins L J
School of Veterinary Science, University of Bristol, Langford, United Kingdom.
Poult Sci. 1998 Dec;77(12):1798-802. doi: 10.1093/ps/77.12.1798.
The major welfare concern during the handling of laying hens is that of broken bones. With particular reference to the United Kingdom, this paper reviews the work that has been done to quantify the problem, to examine the causes, and to investigate factors that affect it. The number of freshly broken bones found in live birds prior to slaughter and the number of old healed breaks found at slaughter are unacceptably high. End-of-lay hens from battery cages have especially fragile bones and these are easily broken during the rough handling that is received during depopulation. Birds from more extensive laying systems have stronger bones and suffer fewer breaks during depopulation but have a greater prevalence of old healed breaks. The old breaks occur as a result of collisions due to poor design within these housing systems. The number of fresh breaks can be reduced by increasing bone strength and handling birds with more care. The numbers of old breaks can be reduced by better design of housing systems and the physical environment within them.
在处理产蛋母鸡过程中，主要的福利问题是骨折。本文特别以英国为例，回顾了为量化该问题、研究其成因以及调查影响因素所开展的工作。在屠宰前活禽身上发现的新骨折数量以及在屠宰时发现的陈旧愈合骨折数量高得令人无法接受。来自层架式鸡笼的产蛋末期母鸡骨骼尤其脆弱，在清栏时受到的粗暴处理过程中很容易骨折。来自更宽敞养殖系统的母鸡骨骼更强壮，在清栏时骨折较少，但陈旧愈合骨折的发生率更高。这些陈旧骨折是由于这些养殖系统设计不佳导致碰撞造成的。通过增强骨骼强度和更加小心地处理禽类，可以减少新骨折的数量。通过优化养殖系统及其内部物理环境的设计，可以减少陈旧骨折的数量。
