However, in some cases, artificial insemination is practiced. The turkey industry especially depends on artificial insemination since natural mating is virtually impossible as a result of intense genetic selection for confirmation and body weight. The completed mating occurs when the rooster dips his tail to the side of the hen's tail and spreads his tail feathers so that their cloacae come in contact. At this point the rooster's ejaculate is released directly into the hen's vagina via cloaca. In the typical breeder house with thousands of birds, the entire sequence of behaviors does not always occur, and the courtship dance is frequently left out of the sequence.
Chickens are polygamous, but certain males and females selectively mate regularly.
Some females in the flock will show avoidance to specific males, and therefore are rarely mated by those males. The rooster usually ejaculates between 100 million and 5 billion sperm at a time with greater concentrations produced at the beginning than at the end of the day, when depletion occurs due to multiple matings. A rooster may mate from 10 to 30 or more times per day, depending on the availability of hens and competition from other roosters. The numbers of sperm per ejaculate and the volumes of semen should be lower in natural matings as compared to semen collection by stimulation and massage. The frequency of mating follows a diurnal pattern with mating frequency reaching peaks early and late in the day.