Sex Identification of Jersey Black Giant, Jersey White Giant, and White Plymouth Rock Chicks by Down, Shank, and Beak Color

Abstract

IN A previous paper by Quinn and Knox,**Quinn, J. P., and C. W. Knox, 1939. Sex identification of Barred Plymouth Rock chicks by down, shank, and beak characteristics. Poul. Science, 18:259. it was shown that intensity of down color and shank pigment in Barred Plymouth Rock chicks enabled the investigators to identify the sexes of 307 unselected hatchery chicks with an accuracy of 91.8 percent. Among the Barred Plymouth Rock chicks observed, the down characteristics proved to be fully as reliable an index of sex as the shank characteristics. It was known that in certain other colored as well as white varieties, considerable variability was evident in the down color of the chicks and that an apparent relationship between the down color groups and the sexes seemed to exist. Observations on down, shank, and beak characteristics were made, therefore, on three varieties of chicks, one colored, the Jersey Black Giant, and two white, the Jersey White Giant, and the White Plymouth Rock. After the observations were made, the chicks were dissected to ascertain .