The Farm Animal Welfare Council of the United Kingdom has issued an opinion on osteoporosis and bone fracture in laying hens. The FAWC is a science-based consortium representing leading research specialists in aspects of management, physiology, welfare and behavior and advises the UK government on proposed regulations.
In 2009, 46% of UK hens were housed in conventional cages, 6% in enriched cages, 4% in barns and 32% under free range/pasture management.
A survey conducted in 2006 to evaluate the prevalence of “old fractures” including healed keel bones, wing and leg bones showed a relatively high rate of previous injury. The survey showed 23% of hens from conventional cages with healed fractures. The corresponding value from enriched cages was 27% and inexplicably, 42% from barns and 44% from free range.
Similar results were obtained by scientists at the University of Bristol surveying 67 flocks in enriched and non-confined housing. A total of 36% of hens from enriched cages showed fractures of the keel bone, ranging from 45% to 86% of hens examined. Investigators attributed the high proportion of fractures of the sternum to poorly designed and inadequately positioned perches.
The report considers osteoporosis in relation to genetics, nutrition, management and housing with an evaluation of contributory factors. The chairman of the FAWC, professor Christopher Wathes, concluded “the Council would ideally like to see bone damage in live birds eliminated entirely and to that end the egg industry and the government should be working towards a strategy of time-related reduction in bone fractures during laying and at depopulation.”