The problem of broken bones during the handling of laying hens - A review

The major welfare concern during the handling of laying hens is that of bro ken bones. With particular reference to the United Kingdom, this paper revi ews the work that has been done to quantify the problem, to examine the cau ses, and to investigate factors that affect it. The number of freshly broke n 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 batt ery cages have especially fragile banes and these are easily broken during the rough handling that is received during depopulation. Birds from more ex tensive laying systems have stronger bones and suffer fewer breaks during d epopulation but have a greater prevalence of old healed breaks. The old bre aks 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 stre ngth and handling birds with more care. The numbers of old breaks can be re duced by better design of housing systems and the physical environment with in them.