Individual heterosis for birth weight of N’dama crossbred calves in Sub Sahara region of Africa.

Birth weight records of 1137 calves of which 94 were straight bred and 1043 were crossbred (545 males and 592 females) from crosses with two indigenous breeds Muturu and Keteku and seven breeds, Brahman, Angus, Charolais, German Brown, Hereford, Jersey and Santa Getrudis collectedfrom Fasola Stock Farm were analyzed for individual heterosis on birth weight and survivability. Statistical model used for the analysis include sex of calf, calf genotype, year of birth, and season of birth. It also includes interaction between calf sex by year of birth and calf sex by season of birth. The effect of sex of calf, calf genotype and year of birth were highly significant (