Rate of Growth and Calcification of the Sternum of Male and Female New Hampshire Chickens Having Crooked Keels

WARREN (1937), at the Kansas Agricultural Experiment Station, reported experiments which showed that tendency of chickens to develop crooked keel was definitely hereditary and was influenced by early roosting conditions. He also reported that crooked keel usually developed before maturity and most frequently when the chickens were between the ages of 6 and 12 weeks. In the keel bones he analyzed, of eight-weeks-old chicks, he found the percentage of ash in the crooked keel was less than in the straight keel bones. He further showed that crooked keel occurred more frequently in male chickens. The results of a study (Buckner, et al., 1946) at the Kentucky Experiment Station which concerned the larger bones of 20-week-old laying hens having straight and crooked keels, were consistent with the findings of Warren and together showed that the sternum in the chicken is slower to calcify than the leg bones and that crooked keel . . .