accurate colour sexing without compromising economic traits was achieved. Artificial insemination Artificial insemination is a mechanism in which spermatozoa are deposited into the reproductive tract of a female. Artificial insemination provides a number of benefits relating to reproduction in the poultry industry. Broiler breeds have been selected specifically for growth, causing them to develop large pectoral muscles, which interfere with and reduce natural mating. The amount of sperm produced and deposited in the hen's reproductive tract may be limited because of this. Additionally, the males' overall sex drive may be significantly reduced due to growth selection. Artificial insemination has allowed many farmers to incorporate selected genes into their stock, increasing their genetic quality. Abdominal massage is the most common method used for semen collection. During this process, the rooster is restrained and the back region located towards the tail and behind the wings is caressed. This is done gently but quickly. Within a short period of time, the male should get an erection of the phallus. Once this occurs, the cloaca is squeezed and semen is collected from the external papilla of the vas deferens. During artificial insemination, semen is most frequently deposited intra-vaginally by means of a plastic syringe. In order for semen to be deposited here, the vaginal orifice is everted through the cloaca. This is simply done by applying pressure to the abdomen of the hen. The semen-containing instrument is placed 2–4 cm into the vaginal orifice. As the semen is being deposited, the pressure applied to the hen's abdomen is being released simultaneously. The person performing this procedure typically uses one hand to move and direct the tail feathers, while using the other hand to insert the instrument and semen into the vagina. General biology Modern commercial broilers, for example, Cornish crosses and Cornish-Rocks, are artificially selected and bred for large-scale, efficient meat production. They are noted for having very fast growth rates, a high feed conversion ratio, and low levels of activity. Modern commercial broilers are bred to reach a slaughter-weight of about 2 kg in only 5 to 7 weeks. As a consequence, the behaviour and physiology of broilers reared for meat are those of immature birds, rather than adults. Slow growing free-range and organic strains have been developed which reach slaughter-weight at 12 to 16 weeks of age. Typical broilers have white feathers and yellowish skin. Recent genetic analysis has revealed that the