Assessing the Feasibility of Using Ambient Temperature Semen and Prostaglandin-Based Synchronisation in Beef Cattle under Tropical Conditions of Tanzania

Abstract

Artificial insemination (AI) services for the Mpwapwa breed of cattle in Tanzania have been in abeyance for many years, largely due to difficulties of supply of liquid nitrogen to remote and rural areas. Historically, AI using unfrozen ambient temperature or chilled semen have been effective alternatives to cryopreserved (frozen) semen, subsequently, AI using ambient temperature semen could form the basis of an AI service for the Mpwapwa region (and other similar areas across East Africa). However, the feasibility of using ambient temperature semen needs testing in field conditions. In this study 151 Mpwapwa cows were synchronised using a standard 14-day double prostaglandin (PG) programme and inseminated using ambient temperature semen (AT). Cows showing oestrus after the first PG injection were inseminated accordingly; all other cows were inseminated at ~56 hours after second PG. Bulls were then run with the cows for 60 days, after which conception rates to AI and overall pregnancy rates were determined by transrectal ultrasonography. Conception rates to AI with AT semen were 62% (94/151), while final pregnancy rates (after natural mating) were 96% (145/151). In this study, the conception rate to AI with ambient temperature semen was at least as good as that which has been achieved with frozen semen under similar conditions, and costs were at least half of the costs to create and use frozen semen, demonstrating the potential of AT semen to be used in rural Tanzania.