Broiler breeders — the parent birds that produce commercial broiler chickens — are selectively bred for rapid growth but must be kept hungry to prevent fatal weight gain. This creates one of the most profound and under-recognised welfare problems in the poultry industry.
Broiler breeder welfare represents a paradigm case of a welfare problem created entirely by genetic selection decisions. The birds themselves did not evolve this way — they were bred into a physiology that is incompatible with normal feeding behaviour and health. The chronic hunger they experience is not mild background hunger but a powerful, frustrated motivation that drives persistent food-seeking behaviour throughout their lives. Research using cognitive bias tests — which measure whether an animal's overall emotional state is positive or negative — shows broiler breeders in restricted feeding conditions have markedly negative affective states compared to normally fed birds. The welfare cost is not incidental or unavoidable: it is a direct, predictable consequence of the genetics chosen by the poultry industry for commercial reasons. Transitioning to slower-growing genetics that do not require severe feed restriction to survive to reproductive age is technically achievable and would dramatically reduce the welfare burden on the hundreds of millions of breeder birds kept globally.