In the egg industry, the sex of day-old chicks is determined at the hatchery. Sexing chicks (determining whether they are a hen or a rooster) requires considerable skill and is done at this very early stage to determine their fate.
If strong and healthy, the female chicks remain in the hatchery, they are grown to a suitable size and then transferred to a laying facility — which could be a caged, free-range or barn set up. Male chicks are considered an unwanted byproduct of egg production and are killed and disposed of shortly after birth.
Male chicks are killed for two reasons: they cannot lay eggs and they are not suitable for chicken-meat production. This is because layer hens — and therefore their chicks — are a different breed of poultry to chickens that are bred and raised for meat production. Layer hens are bred to produce eggs whereas meat chickens are bred to grow large breast muscle and legs.
Chick hatcheries breed one or the other type of chick depending on which poultry industry they supply — egg or meat. At the layer-hen hatcheries supplying the egg industry with layer hens, the eggs are developed in industrial incubators. Once hatched, the newborn chicks pass down a production line to be sexed and sorted. Sick or weak female chicks and all male chicks are separated from the healthy female chicks and then killed.
The Model Code of Practice for the Welfare of Animals: Domestic Poultry states that all culled or surplus newly hatched chicks that are destined for disposal must be treated as humanely as those that will be retained or sold. They must be destroyed promptly by a recommended humane method such as carbon dioxide gassing or quick maceration. Chicks must then be carefully inspected to ensure they are all are dead.
Quick maceration ensures the chick is killed within a second and, if carried out effectively and competently, this method may be considered more humane than gassing with high concentrations of carbon dioxide. Gassing results in gasping and head shaking and, depending on the mixture of gases used, it may take up to two minutes for the chick to die.
The RSPCA continues to urge the egg industry to invest in alternatives that avoid the potential for pain and suffering with current killing methods of male chicks. For example, research into alternatives to allow chick sex to be determined in the early egg incubation phase should be urgently progressed.