Parent broiler chickens are kept chronically hungry throughout their lives to prevent obesity and health problems driven by genetic selection for rapid growth in their offspring.
Broiler breeder feed restriction represents one of the most clearly documented cases of chronic suffering in commercial animal farming. The hunger is not incidental but designed: parent birds must be kept in a state of permanent caloric restriction because their genetics — selected for maximum growth in their offspring — would otherwise cause fatal obesity in themselves. The welfare harm is both scientifically well-documented and paradoxical: we have created animals that must be chronically hungry or die, and the solution to the welfare problem is to change the breeding programme rather than to change the management. Some producers are developing moderate-growth parent lines, but the commercial pressure toward maximum growth genetics is difficult to overcome without regulatory intervention or market incentives.