High ammonia concentrations in broiler sheds cause painful eye conditions including keratoconjunctivitis in a significant proportion of intensively housed chickens.
Ammonia-induced eye damage in broilers is a significant and preventable welfare problem that receives insufficient attention. Birds with conjunctivitis experience eye pain that is chronically disabling - visually impaired birds cannot navigate flocks, find resources or avoid threats. The condition develops progressively over the growing period as ammonia concentrations accumulate in poorly managed sheds. Good litter management, appropriate ventilation and reduced stocking density prevent most cases. Including eye condition scoring in welfare assessment provides a welfare outcome measure that reflects real in-shed conditions and can be used to hold producers accountable.