Effect of Gonadotrophin-Releasing Hormone and Human Chorionic Gonadotrophin on the Response of the Ewe to Pregnant Mare Serum Gonadotrophin

Abstract

An experiment was conducted to determine whether gonadotrophin-releasing hormone (Gn-RH)

Superovulation and embryo production in ewes using a commercial p-FSH

“…A decrease in the number of ova fertilized and transferable embryos at high doses of exogenous gonadotrophins has also been reported in other reports in both sheep (Moor et al, 1985) and cattle (McGowan et al, 1983;Donaldson and Ward, 1985;Donaldson et al, 1986). It has been demonstrated that high levels of gonadotrophins alter endocrine profiles (Quirke and Hanrahan, 1975;Whyman and Moore, 1980 ;McNatty et al, 1982), biochemical functions of oocytes (Moor et al, 1985) and sperm transport (Armstrong and Evans, 1984). All this may negatively influence the number and quality of fertilized ova.…”

Ovarian Response to PMSG Treatment in Ewes Immunized against Oestradiol-17ß

“…It is possible that by giving an ovulating agent such as human chorionic gonadotrophin or luteinizing hormone releasing hormone (Nancarrow et af. 1984;Quirke and Hanrahan 1975) advantage may be taken of the increased ovarian response that was exhibited by some groups of ewes, particularly group A after treatment with 1500 i.u. PMSG.…”