Fundamental aspects of ovum transfer in cattle
Newcomb, R.
Veterinary Record 99(3): 40-44
1976
ISSN/ISBN: 0042-4900 PMID: 785792 Document Number: 108505
Although it may ultimately be possible to fertilize ovarian follicular oocytes in vitro, superovulation and insemination are currently the only practical methods for obtaining a supply of fertilized ova. It is likely that this will remain true for some time to come. Pregnant mares serum gonadotrophin (PMSG) is almost universally used for inducing superovulation, and response to it has recently been more reliably achieved by using, in addition, prostaglandin F2 alpha to induce oestrus in superovulated donors. The recovery of fertilized ova from donors depends on the expected site of the ova within the genital tract, but both surgical and non-surgical methods involve suspending the ova in a stream of fluid which is collected into glass cups and examined microscopically. A variety of in vivo and in vitro environmental conditions affect the success of transfer of fertilized ova. These include the healthy state of the recovered ovum, the storage medium, the method and length of storage, the age of the ovum and the synchronisation of oestrus of donor and recipient.