First things first, a rooster does not impregnate a hen. Hens do not get pregnant, they lay eggs which can be fertile or not. Eggs are fertilized when a rooster mates with a hen. read more
The chicken sexer takes one quick look and slides the chick down one chute or the other. A skilled chicken sexer can sex 1200 chicks per hour, which gives them three seconds per chick. read more