About us

The Royal Veterinary College and The University of Manchester have a group of researchers (found here) dedicated to answering why almost 30% of our broiler chicken population (800 million bred for human consumption in the UK alone) develop some form of lameness, as well as suffering from heart and lung problems.

This is a major welfare concern for the poultry industry and there is controversial evidence that slaughter-age broilers are in pain.  It also has an economic impact costing the UK industry around £20 million per year.

Leg health issues and heart/ lung problems are linked to selective breeding for rapid growth rates- broilers take only 6 weeks to reach a slaughter mass of almost 3kg (6.6 lbs), a threefold increase in growth rate in about sixty years. Broilers can suffer from heart failure and leg weakness (an umbrella term used for conditions associated with a lack of walking ability/ lameness), and activity levels decline steeply as broilers age.

Interested in what we do, how we do it and what we’ve found out? Read all our latest research news here.

We are developing a new scientific framework for understanding how the bodies of broilers change as they grow, focusing on the functions of the legs and their muscles during standing and walking, and the functions of the chest muscles during breathing when standing, sitting and walking.

This framework is founded on an extremely rigorous three-dimensional analysis (using x-rays, force platforms and other tools) of how the skeleton actually is moved by the muscles during locomotion and breathing.  It combines cutting-edge techniques for the experimental analysis of gait (including stability) and breathing (including metabolic energy cost for different activities) with anatomically-realistic 3D computer simulations of how the musculoskeletal system produces observed motions.

Our novel synthesis of these approaches allows us to tease apart how the body shape and posture of broilers changes as they grow and how these changes influence standing, moving and breathing. It will reveal tradeoffs between growth, health and behaviour, by filling a major gap in our understanding of broiler biology.

We suspect that at 2 weeks of age broilers are quite adept at locomotion and breathing but these abilities tend to decline at 4 weeks and approach limits of viable performance at 6 weeks old. These declines could be driven by the rapid growth of edible breast muscles that make the body “front heavy,” destabilizing the animal and causing the legs to work harder for support, and concurrently incurring breathing difficulties. This vicious cycle would lead to fatigue, inactivity and poor health that has parallels with the human obesity crisis, but there is no simple solution to it.

Understanding what selective breeding has done to the detailed anatomy of broilers and how this has affected their functional abilities is pivotal to any solution to the two related crises of leg and lung health in broilers. Furthermore, there may be an optimal body structure (such as larger legs, different breast muscle distribution) at some point early in chicken growth. This optimum could be promoted by selective breeding to reduce these problems if it were determined scientifically- as we intend.

Our study will provide a new understanding of the linkages between anatomy, growth, standing and moving, breathing and metabolic energy consumption in broiler chickens that would enable us to forge a new way of assessing which chickens move and breathe the best and why. This will help scientists, veterinarians and industry to work together to promote better broiler health and welfare while still feeding the world.

Above: 3D image of a junglefowl’s anatomy (lungs and air sacs involved in breathing in blue; bones in orange; skin/feathers/muscle in yellow). We are using similar imaging techniques to measure the anatomy of chickens, and then using such measurements to determine how they breathe and move.