Abstract :
The objective of this study was to evaluate a protocol for superovulation in goats designed
to use the animals’ endogenous progesterone production, compared to a common protocol
that utilized exogenous progesterone. The numbers of non-ovulated follicles, ova
ovulated, and ova collected for each protocol were compared. In addition, the effect on
these parameters of the day of first FSH administration, relative to the second follicular
wave was investigated in the endogenous progesterone group. Forty alpine goats were
divided into two groups. The +CIDR group (n = 20) received PGF2 7 days prior to CIDR®
insertion (CIDR insertion = day 0). The CIDR® was inserted for 14 days, and during this
period PGF2 was injected on day 7 and FSH given in 8 equal doses over 4 days, starting
on day 12. For the −CIDR group (n = 20), estrus was checked daily after an initial dose of
PGF2 to allotted females that were approximately 7 days (range: 6–9 days) from estrus,
when the first dose of FSH was administered. FSH (8 equal doses over 4 days) was administered,
and PGF2 given on the second day of FSH administration. In both groups GnRH
was given approximately 15–17 h after the last dose of FSH and surgery to collect early ova
was performed 27–30 h later, to evaluate the superovulatory response. No significant differences
in the mean numbers of non-ovulated follicles (+CIDR: 5.4 ± 0.8, −CIDR: 5.6 ± 1.0)
and ovulation points (+CIDR: 13.8 ± 1.0, −CIDR: 13.7 ± 1.4) per doe were observed, nor in
the total number of ova collected per female (+CIDR: 9.6 ± 1.2, −CIDR: 9.3 ± 1.4). In addition,
no relationship of these parameters with the day of initial FSH administration in the −CIDR
group was found. In conclusion, it was shown that if the time of estrus can be identified,
superovulation can be reliably produced in goats, without the need for an exogenous source
of progesterone.
