Inheritance of Broodiness in Japanese Nagoya Fowl, with Special Reference to Sex-Linkage and Notice in Breeding Practice

IT IS obvious that broody instinct is a heritable trait from the facts that there exist breed or strain differences in the degree of broodiness and it can be eliminated by selection. Many investigators reported the non-broody birds to be higher in annual egg production than the broody ones (Hays and Sanborn, 1926, 1927; Hays, 1933; Knox, Jull and Quinn, 1935). Hays (1944) and Lanson (1948) reported that the average year’s record of the non-broody group was only slightly higher than that of the broody one. The genetic mode of broodiness has not yet been clarified. In an earlier study, Goodale et al. (1920) reported that broodiness may be manifested by complementary genes from the results of interbreed crossing. From the proportion of broody to non-broody birds in various crossings, Punnett and Bailey (1920) showed broodiness to be expressed by more than one independent autosomal gene. Since sex-linkage of broodiness …