Abstract
Pregnancy rates (PR) were studied in cattle of Bunaji (White Fulani} and Bokoloji (Sokoto Gudali) breeds following artificial insemination (Al) with semen of indigenous, exotic or crossbred bulls. Herds were classified into supplemented or unsupplemented depending on whether or not they received supplementary concentrates during the dry season. The effect of season (dry, November-April; and wet, May-October) on pregnancy rates was also determined. Overall PR were 59.3 and 32.8%, for supplemented and unsupplemented herds respectively. PR of animals inseminated in the wet season was 56.0% significantly higher than the PR of cattle inseminated in the dry season (32.3%). Seasonal differences were also observed for both supplemented and unsupplemented groups, but the effect of season was more marked in the supplemented than in the unsupplemented group. The implications of these results in Al programmes in Nigeria are discussed.
