Utilization of exotic germplasm for milk production in the tropics

Results from 80 Reports in the literature on crossbreeding in the tropics were summarised to study the relationship between dairy performance and proportion of exotic genes. Grades higher than 1/2 exotic did not perform any worse than the Fl in all traits, except calving interval which was longer in higher grades. The relationship between performance and proportion of European genes differed among breeds. The Friesian crosses were not any better than crosses involving Jersey, Brown Swiss, Ayrshire or Red Dane. F2 performance was lower than that of F1 but subsequent generations (F3 and F4) were not any worse than F2. .