Broiler breeders — the parent birds of meat chickens — are kept in chronic hunger to prevent obesity-related health problems.
Broiler breeders experience a fundamental welfare dilemma: they are genetically programmed to eat constantly, but unrestricted feeding kills them. The solution — chronic food restriction — keeps them in a constant state of hunger and frustration. This is an engineered welfare problem with no good solution under current genetics, motivating breed-change campaigns.