Evaluation of fertility and calving ease of small holder indigenous cattle herds in semi-arid zone of Nigeria

This study had the objective of determining the fertility and calving ease of small holder indigenous cattle herds inseminated with imported semen from proven sires. Sixty one indigenous cows of different breed origin (Bunaji, Sokoto Gudali and Rahaji) were selected from different herds across Jigawa state-Nigeria, and were used for this study. The selected dams were inseminated with semen from proven bulls of three exotic breed origin (Holstein-Friesian, Brown Swiss and Gwuzera) using artificial insemination technique. Pregnancy diagnosis was conducted by rectal palpation 40 days after insemination to ascertain the pregnant ones; those that were not pregnant were re-synchronized and inseminated. The number of inseminations per cow per conception was recorded. Calving ease was evaluated and coded in two classes; 1 (unassisted calv-ing) and 2 (assisted calving) while calf survival was 0 if the calf died within 24 hours from birth and 1 oth-erwise. The results showed that 54% of the cows had normal calving while 46% were assisted. Amongst the assisted calving, 89% of the calves survived while 11% died. The age, parity and dam body condition had significant effect (P < 0.01) on calving ease of the dams. Calving ease increased with age, parity and body condition of the dam. The sire breed origin had no significant (P > 0.05) effect on the number of insemina-tion per conception but significantly influenced gestation length. Dam breed origin significantly (P < 0.05) influenced number of insemination per conception and gestation length. The sire-dam breed combination showed that Holstein-Friesian-White x Fulani cross had the lowest percentage of calving difficulty (17%) with 0 mortality, indicating the high compatibility of these two breed origins. However, Sokoto Gudali was more compatible with all the 3 exotic sire breed origin Holstein friesian, Brown Swiss and Gwuzera stud-ied with no mortality recorded. Therefore, results of this study on Bos taurus cattle and their crosses (Bos taurus x Bos indicus) suggests that the Sokoto Gudali dams are much more compatible with all the three exotic sire breeds, (Brown Swiss, Holstien-Friesian and Gwuzera) for crossbreeding purposes than White Fulani and Red Bororo dams.