A study was carried out on data collected between 1970 and 1979 on the crossbreeding of cattle in Vom using British Friesian, Brown Swiss and Jersey bulls. Only crossbreeding involving Friesian bulls was successful. There were progressive increases in lactation yield, yield per day of lactation length, lactation length, daily fat yield, birth weight and calving interval in the grades with increases in the Friesian contribution. The daily fat concentration however decreased with the increase in Friesian proportion. Most of the genotypes namely, pure White Fulani, 0·5 Friesian: 0·5 White Fulani; 0·75 Friesian: 0·25 White Fulani, 0·875 Friesian: 0·125 White Fulani and pure Friesian calved regularly each year. Phenotype correlations between lactation length and yield for most of the genotypes were high, positive and significant.