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 collected from 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 (P<0.001) on birth weight. The interaction of calf sex by year of birth was also highly significant (P<0.01), while season of birth was significant (P<0.05) on birth weight. Among the F1 crossbred calves 50% Muturu - 50% N’Dama have the highest individual heterosis of 17.66% while the least (-26.82%) was from calves with 50% charolais - 50% N’Dama blood. In the F2 crosses the highest individual heterosis of 4.96% was recorded for 25% Brahman-25% N’Dama x 50% Muturu calves and the least (-4.50%) was recorded for 52% Brahman - 25% N’Dama x 50% Keteku. For F3 crosses the only crossbred calves that survived was 12.5% Brahman - 87.5% N’Dama with individual heterosis of -2.95%.