The modern commercial broiler is reared in enclosed sheds that may contain 50,000 birds to reach killing weight at an age of 42 days. This rate of production has been achieved mainly by genetic selection for rapid growth, and it has created a number of welfare problems, the most serious of which is "leg weakness": an industry euphemism for a range of painful limb disorders sufficient to cause lameness.
Fifteen years ago, I wrote that "approximately one-third of the heavy strains of broiler chicken are in chronic pain for approximately one-third of their lives". This view was shared by the UK Farm Animal Welfare Council (Fawc), who stated: "The current level of leg problems in broilers is unacceptable. The Council intends to look at this aspect of broiler production in five years' time, when significant improvements should be apparent. If no reduction in leg problems is found, we may recommend the introduction of legislation to ensure the required improvements."
New evidence presented to Defra reveals that, with notable exceptions, fast-growing strains of broiler chickens are as prone to leg disorders as ever. Moreover, research from Bristol University shows the problem is worse than we thought. Birds that appear only slightly lame will select food containing drugs to ease their pain. All lameness hurts.
Many of the welfare abuses that arise from the factory farming of broilers are faults of management. However the biggest problem is simply that the birds outgrow their strength. Some companies have reduced the problem through control of feeding and lighting, driven, in effect, by the need to reduce the risks of working with birds that are not fit for purpose.
Pressure of public opinion has achieved notable successes in the drive to improve farm animal welfare. Free-range eggs now account for 50 per cent to 100 per cent of total sales in most supermarkets. It is high time to extend our compassion to chickens reared for meat rather than eggs. Much can be achieved through consumer pressure: insistence on buying meat from slow-growing strains of birds reared under proven conditions of high welfare. These birds are in the shops now.
However there is also a need for political action. Fawc called for it 15 years ago but nothing has happened since. The most serious welfare abuse in the broiler industry has been the breeding of animals that are unfit for purpose.
Since the industry is dominated by fewer than five breeding companies that supply more than 80 per cent of the world market, we could remove the greatest abuse of chicken welfare through a ban on the production of birds unfit for purpose. I see no difference in principle between existing law that required egg producers to provide a better cage for laying hens within 10 years and a law that requires broiler breeders to produce a healthier bird.
John Webster is emeritus professor of animal husbandry at the University of Bristol, and author of Animal Welfare: Limping towards Eden