Evaluating the success rates of embryo transfer in recipient cows under farming conditions in Rwanda

Embryo transfer (ET) presents promising opportunities for enhancing dairy production in small-scale farms in Rwanda. This study evaluated the success rates of ET interventions in both on-station and on-farm settings. Conducted in 2018 to 2019, the research involved 26 superovulated embryo donor cows and 208 recipient females (181 cows and 27 heifers) across Board (RAB) in the Southern and Northern Provinces. Additionally, the study included 60 smallholder farms (each under 1 ha) in Nyanza and Musanze districts. The findings revealed an overall pregnancy rate (PR) of 36.2% (n = 127) for both fresh and frozen-thawed embryos, with a significant discrepancy between RAB farms (44.8%, n = 67) and smallholder farms (26.7%, n = 60). Factors such as embryo type, farm ownership, and body condition score significantly influenced PR (P = 0.01, 0.03, and 0.04 respectively), while other variables, including breed, body weight, age, parity, postpartum interval, corpus luteum status, and estrus intensity did not show significant impact (P > 0.05). The study concludes that ET can be effectively implemented within local dairy production systems.