Professor Hutchinson explains what the research will involve: "The poultry industry is a rapidly expanding enterprise (over 870 million broilers slaughtered in the UK annually; DEFRA 2012 statistics) in which artificial selection (also known as selective breeding) has resulted in an extreme organism with noticeable changes to its anatomy, as well as an increase in growth rate (reaching slaughter weight in around 35 days rather than around 15 weeks in the 1960s).

"Unfortunately, coupled with this success of harnessing the power of selection are a number of welfare concerns. Impaired walking ability or lameness is often highlighted as a major problem, affecting up to 30 per cent of broiler populations.

"Beyond these obvious welfare concerns are also economic losses and concerns for future production, especially when continued practice relies on customer and consumer acceptance of the farming practices involved. The pressure to develop ‘healthier’ broiler strains and generally improve welfare standards is therefore paramount.

"Our previous research has led us to conclude that part of the problem these broilers have is related to their anatomy, i.e. creating birds with large breast muscles and increased bodyweight has ultimately changed the way these birds walk and is part of the complex puzzle which surrounds their walking ability and/or lameness.

"We suggest a better relationship between these desired production traits (high meat content and fast growth) and ‘healthy’ walking-related traits could be achieved through targeted artificial selection, ultimately allowing industry to produce chickens with high production efficiency and optimal welfare," added Professor Hutchinson.

Computer model of the right leg and pelvis of a broiler chicken, shown in side view.
(The whitish objects are bones and the red lines represent the lines of action of leg muscles that generate and control walking. The model includes the anatomy, physiology and physics of chickens and their motion, and can predict resulting movements based on those.)

He explained: "We propose to use 3D biomechanical, musculoskeletal computer simulations of a broiler chicken to predict what the effects of selection for specific anatomical traits would have on its locomotion.

"We would focus on the loads placed on leg joints and the metabolic energy costs incurred during walking, because these should directly correlate with (1) the incidence of certain leg pathologies (greater loads should incur greater risks of pathology) and (2) the level of activity or fatigue in broilers (animals with higher costs should walk less often, with knock-on detriments to general health; likewise, animals with greater joint loads also might walk less).

"We would then establish which traits cause the most significant problems and use this information to propose a 'redesign' compromise between the needs of the industry and those of the chicken for improved walking ability," concluded Professor Hutchinson.