How much space does a meat chicken need?

Stocking density (i.e. the space available to the bird) is widely recognised as one of the key welfare determinants for meat chickens. High stocking densities can have negative impacts on many aspects of meat chicken welfare including walking ability, skin lesions due to contact with poor litter, scratches, increased disturbance, greater difficulty managing litter quality, and heat stress. High stocking density also influences the extent to which birds will explore, forage, and express comfort behaviours.

When birds are placed in the shed at one day old, they have lots of space. However, as these chicks grow over the course of 4-5 weeks, the available space relative to their body size gets smaller. Therefore, a common practice in Australia is to remove a portion of the birds from the shed on multiple occasions – this is called ‘thinning’. Removal of birds from the shed is stressful for both the birds being caught and the birds remaining in the shed. The entire flock must often be feed restricted to meet the food safety requirements of the birds being caught, and the presence of the catching team in the shed with their various equipment (including forklifts) is a substantial stressor. Thinning allows the maximum stocking density to be reached on more than one occasion throughout the life of the flock and risks diseases being introduced to the shed.

More space per bird (lower stocking density) is associated with increased activity and reduced lameness, footpad and hock burn, skin scratches, fearfulness, and heat stress in meat chickens.

Rather than thinning, the use of an all-in all-out system where the number of birds placed in the shed on day one takes into account their final market weight such that stocking density is not exceeded throughout their lifecycle) will avoid the unnecessary disruption and stress that multiple thinning events cause to birds. For all-in all-out systems to be successful, all birds should reach the required market weight at the same time. And, because the practice of thinning to meet varying market (consumer) requirements is entrenched in the Australian meat chicken production system, meaningful improvements will require consumers to demand higher welfare and asking retailers for change.