Broiler breeder chickens — the parents of meat chickens — are feed-restricted to prevent obesity while carrying fast-growing genetics, causing chronic hunger that is among the most severe welfare problems in poultry.
Broiler breeder welfare represents a particularly acute welfare problem because the chronic hunger caused by feed restriction is severe and prolonged. Feed-restricted breeders show stereotypic behaviors, persistent foraging activity in bare environments, and behavioral indicators of hunger throughout their breeding lives. Their motivation for food is so strong that they accept bitter-tasting water rather than going without fluid — a behavioral measure of how highly motivated they are to consume anything edible. This is a system-level welfare problem created by the genetics of modern broiler lines — the same rapid growth that causes problems in broilers creates an insoluble dilemma for breeders. Transitioning to slower-growing broiler lines simultaneously improves broiler welfare and reduces the feed restriction severity needed in breeders.