Ejaculate characteristics, short-term semen storage and successful artificial insemination following synchronisation of oestrus in the Indian blackbuck antelope (Antilope cervicapra)

Abstract

The blackbuck (Antilope cervicapra) is a small (20-30 kg) Indian antelope that is listed on Schedule I of the Indian Wildlife Protection Act, 1972. Studies were undertaken to develop assisted reproductive technologies, such as synchronisation of oestrus and non-surgical AI, to support the conservation and genetic management of this Indian antelope. Semen characteristics, testosterone levels and the feasibility of short-term cold storage of semen were investigated. Furthermore, different oestrous synchronisation protocols (norgestomet implants and prostaglandin injections) were evaluated for successful AI, defined as the birth of live young. Norgestomet ear implants and i.m. administration of pregnant mare's serum gonadotropin (PMSG) resulted in successful pregnancies in two of five inseminated females, but both had twin pregnancies that were delivered prematurely. In contrast, two injections of prostaglandin 11 days apart were effective in synchronising oestrus in the blackbuck. Transcervical AI in oestrous-synchronised animals 72 and 96 h after the second prostaglandin injection resulted in successful pregnancies in four of six inseminated females (67%) and resulted in the delivery of three live fawns. These studies demonstrate the potential application of AI technology for the conservation of endangered ungulates. To our knowledge, this is the first report regarding the synchronisation of oestrus and successful non-surgical AI in blackbuck.