FEBRUARY 7, 2008: More than a quarter of broiler chickens have difficulty walking, according to a study funded by Defra.
The Bristol University paper on leg disorders in broiler chickens says this is due to the consequence of modern breeding practises ofintensively-reared birds that has resulted in a huge increase in growthrates.The news will bolster the Chicken Out! campaign by celebrity chefs which calls for higher standards of chicken welfare and aims to get consumers to demand free range birds at supermarkets.Broiler chickens have been subjected to intense genetic selection. In the past 50 years, broiler growth rates have increased by over 300% (from 25g per day to 100g per day). Recently a growing concern that many broiler chickens have impaired locomotion has led to a comprehensive survey of commercial flocks quantifying risk factors.Throughout the world the majority of broilers are reared using very similar, modern, intensive systems of production where birds are confined for their lifetime within high density housing and reared from hatch to slaughter weight within approximately 40 days. However, there is evidence that in optimising traits for production the resulting birds, whilst producing meat at a low cost, have a reduced viability and reduced welfare, with poor walking ability, or locomotion, a primary concern.The project assessed the walking ability of 51,000 birds, representing 4.8 million birds within 176 flocks. It also obtained information on approximately 150 different management factors associated with each flock. At a mean age of 40 days, more than 27% of birds in the study showed poor locomotion and 3.3% were almost unable to walk.The high prevalence of poor locomotion occurred despite culling policies designed to remove severely lame birds from flocks. According to Defra this shows that the primary risk factors associated with impaired locomotion and poor leg health are those specifically associated with rate of growth.The British Poultry Council have claimed that these findings are already put into practise by chicken producers. They say that chicken producers have continued to work with Bristol and have changed flock management practices in line with the study’s findings.These changes, such as longer dark periods to give the birds more rest, meal-time feeding in the earlier weeks, and the addition of whole wheat to chickens’ feed have significantly improved overall leg health. Since the study was undertaken, new genetic stock has been introduced into the UK chicken sector which has improved the leg health of the breed highlighted in the study.According to the British Poultry Council British chicken producers take welfare very seriously as the companies’ full participation in these welfare studies demonstrates. It said chicken producers heed the practical findings of these studies and implement them to improve the overall health and welfare of their flocks.