A hatchery is used to raise eggs under controlled conditions. Most poultry hatcheries in the United States operate under a vertically integrated system, where the company that owns or supplies the hatchery also owns the breeder chickens. Companies typically enter contracts with poultry farmers to produce hatching eggs or hire employees to operate the hatchery.
Once eggs arrive at a hatchery facility they are moved through a process of stages. Because the eggs are fragile, all handling is minimized. Once arranged on trays, the eggs are then stored at 55-65° F and 70% humidity for 10 days in egg holding or “egg-cooler” rooms. From here, eggs are moved into a pre-incubation warming room to dry any condensed humidity in the warmer air. Next, the eggs are “loaded” to a setter. Inside the incubator, strict environmental conditions are maintained for 20 days. From here “candling” can be performed in order to assess quality by shining a bright light through the eggs. The eggs are moved to hatching baskets on the 21st day when the chicks are ready to hatch. The last 15% of their time in the process the eggs spend in the hatcher where the chicks emerge from the eggs. Once most of them are hatched and dry, “pulling the hatch”, or removal of the chicks takes place.
Next, in the case of layer hens, “sexing” takes place – separation of chicks into male and female. In many cases, male chicks are killed mechanically by a “macerator” or a rotating “grinder” that crushes the day-old chicks to death.