Abstract :
The effect of a short pre-treatment with a GnRH antagonist (Cetrorelix acetate) and the
induced superovulation response was evaluated in goats. A total of 16 nanny goats were
allocated to two groups. The goats in the antagonist treatment group (n = 8) received 6
doses of the GnRH antagonist, once daily, as a pre-treatment to superovulation. The does in
the control group were provided with saline only. Natural mating was implemented using
three fertile bucks. Large follicles on the ovaries were detected via ultrasound at 3.5 MHz.
All goats were laparotomized and the CL’s and cystic follicles visually recorded. Embryos
were recovered via flushing and recorded 6 days after sponge removal. The number of large
follicles induced and embryos produced were significantly increased by treatment. However,
no differences were noted regarding the numbers of cystic follicles, indicating a lack
of negative side-effects following the use of GnRH. In general, the number of large follicles
and embryos were significantly (P < 0.05) higher in the treated group. It was demonstrated
that a GnRH antagonist treatment can improve the superovulatory response by 64% and
embryo recovery rate by 90% in goats.
