Abstract

This study investigated apparent reproductive failure occurring in seasonally anoestrous progesterone-primed red deer hinds when they were induced to ovulate with the GnRH analogue, buserelin. In March 1988 (non-breeding season), each of 11 progesterone-primed red deer hinds(Groups B and BO) were injected i.m. with 4, 3, 2, 2 and 10 ug buserelin (Receptal, Hoechst) at -48, -24, 0, 24, and 48 h relative to the time injected i.m. with 500 ug oestradiol benzoate. During the breeding season (April), ovulation was synchronised in another 4 hinds (Group C) using CIDRs. Oestrous behaviour was less noticeable and delayed (P>0.05) in Group B hinds and peak LH levels were lower (P>0.01) and occurred later (P>0.01) relative to Group ), BO and C hinds. Two weeks after CIDR withdrawal 3/5 B, 2/4 O, 3/6 BO and 4/4 C hinds had a corpus luteum present. During theses two weeks plasma progesterone levels were elevated in B, BO and C hinds but were low in the O hinds. None of the buserelin- and/or oestradiol-induced ovulations resulted in pregnancy. These results show that ovulations induced in these anoestrous red deer hinds by the use of a GnRH analogue or oestradiol were not accompanied by normal hormonal and behavioural patterns.

T, Wuliji, RN Andrews, GH Davis, and PA Farquhar

Proceedings of the New Zealand Society of Animal Production, Volume 50, , 495-498, 1990