Abstract
Lactation and reproductive data of 573 Bunaji (White Fulani) and 315 Bokoloji (Sokoto Gudali) calvings were studied for three years at the Shika Agricultural Research Station. Zaria, Nigeria. Milk yield was significantly different between breeds, the means being 1144 and 1070 kg in Bokoloji and Bunaji breeds, respectively. Lactation lengths were also significantly different, the respective values were 266 and 255 days in Bokoloji and Bunaji breeds. The difference in milk yield between the two breeds cannot be solely explained in terms of the variation in lactation length since breed differences were significant even when lactation length was included as a covariate. Milk yield increased with parity in both breeds, especially in Bokoloji breed, the percentage increase in the second and third parities over the first for Bokoloji was 23. 7 and 48.4%, while that for Bunaji breed was 0.35 and 2.6%. Adjustments for lactation length resulted in milk yields being very similar in all parities. The overall calving interval for the two breeds was 365 days and did not differ between breeds; parity had a significant effect on calving interval the calving interval after the first parity being longer by ? 18 days than after later parities.
