Male chicks in laying hen hatcheries are killed at hatching because they cannot lay eggs and are the wrong breed for meat.
The mass killing of male chicks represents one of the most ethically troubling practices in conventional food production. The scale — billions of deaths annually — is difficult to comprehend. Maceration and CO2 gassing are the most common methods; both kill effectively but the scale of the operation is a welfare concern in itself. In-ovo sexing technology offers a welfare-positive alternative by identifying male eggs before hatching, eliminating the need to kill hatched chicks. The cost premium is trivial relative to the welfare benefit.