Factors Influencing Conception Rates of Cameroonian Zebu Cattle (Bos Indicus) Following Oestrus Synchronisation and Artificial Insemination.

Abstract

A study was carried out to identify and evaluate factors affecting variation in conception rate (CR) in Cameroonian Zebu cattle following oestrus synchronisation and artificial insemination (AI). Two hundred and six local female Zebu cattle were evaluated to determine relationship among lactation number, age, body condition score (BCS), days postpartum and conception rate. Animals received an intravaginal progesterone release device (PRID^®) containing 1.55mg of progesterone and a capsule with 10mg estradiol benzonate for 10 days and were treated with luteolytic dose of PGF2∝ and 1000mg IU PMSG at the time of PRID^® withdrawal. Animals were inseminated 48 hours after PGF2∝ and PMSG injection. Pregnancy status was assessed by observed non-return to oestrus and confirmed by rectal palpation 55-60 days after insemination. The overall CR was 47.6%. CR was influenced (p< 0.05) by lactation number, age and days postpartum of cows. The multivariate logistic regression model used revealed that CR was optimum in primiparous cows, those between 4.5 -7 years old and 151-300 days postpartum.