Sex Identification of Barred Plymouth Rock Baby Chicks by Down, Shank, and Beak Characteristics

Abstract POULTRYMEN have been interested in segregating male and female chicks at hatching time for practical reasons. This has been accomplished by making sex linked crosses involving color of plumage, by mating rapid-feathering males to slow-feathering females, and by observing the copulatory organ, a method of sex prediction known as the Japanese method. Bureau of Animal Industry investigators at the National Agricultural Research Center have been interested for some time in the possibilities of distinguishing the sex of baby chicks, of standard breeds and varieties, by the observation of such external characteristics as down color, down striping, beak color, or shank color. It has been shown previously (Byerly and Quinn, 1936) that spotting and striping may be used to determine sex in Rhode Island Red baby chicks, 84.9 percent of the striped and spotted chicks being females, and 77.8 percent of the non-spotted, non-striped chicks being males. It was also demonstrated . . .