Asian Journal of Biochemistry, Genetics and Molecular Biology

The aim of this study was to investigate the effects of animal trait and level of local cattle gene inheritance on the expressed levels of heterosis in crossbreeding of exotic German brown and local N’dama. Records from 199 pure bred German brown and N’dama and 308 crossbred calves from the Teaching and Research Farm of the University of Ibadan, Nigeria, were analyzed. Individual Heterosis (IH) calculated, first, on the basis of their Parental means, and secondly, on the basis of the purebred N'Dama mean. Eight traits of critical importance studied were mortality rate, calving rate, age at 1^st calving, calving interval, birth weight, 12-month weight, average daily weight gain from 1-12 months, lactation milk yield and length.  On the basis of the Parental means, IH was positive in all traits for 50% Ndama-bred, positive in 7 out of 8 traits for 75% N’dama-bred, positive in 4 out of 8 for 37.5%- and 25% Ndama-bred each. On the basis of local N’dama mean, it was positive in all traits for 50%- and 75% N’dama-bred, positive 7 out of 8 for 37.5% N’dama-bred and 6 out of 8 for 25% N’dama-bred. It can therefore be concluded that genotypes with 50%- and 75% N’dama blood demonstrated the most consistent performance, exhibiting positive heterosis in all eight traits studied. The findings recommend the use of N’dama crossbreds with approximately 50% to 75% local inheritance for commercial breeding purposes, as these combinations offer superior overall performance and stability across multiple traits in Ibadan environment.