Abstract:
This study was conducted to evaluate the use of one shot follicle stimulating hormone (FSH)
plus equine chorionic gonadotrophin (eCG) (simplified) superovulation protocol in mature
Boer goat does. Eighteen does used were allocated into two groups, during the natural
breeding season (autumn). The two group were Group 1: the control (n = 9); multiple FSH
protocol and Group 2: treatment group (n = 9); one shot FSH plus eCG protocol. All does were
synchronised for oestrus, using controlled internal drug release dispensers (CIDR’s) for 9
days. Does in the multiple FSH protocol group were superovulated with 200 g pFSH/doe,
administered i.m. in 7 dosages at 12 h intervals, starting 48 h prior to CIDR removal. In
the treatment group (one shot FSH plus eCG protocol), the superovulation treatment was
administered once as 200 g FSH plus 350 IU eCG, 48 h prior to CIDR removal. All does
were then observed for oestrous behaviour twice daily, at 12 h intervals following CIDR
removal for a period of 72 h. Cervical inseminations (with 0.1 ml fresh undiluted Boer goat
semen) were performed 36 h and 48 h following CIDR removal. Embryos were then surgically
flushed on day 6 following the second artificial insemination. The time interval
from CIDR removal to onset of oestrus was not affected by treatment. The duration of the
oestrous period however was significantly longer in the one shot group, compared to the
multiple FSH protocol. Does from the one shot FSH plus eCG protocol recorded a significantly
(p < 0.05) lower mean number of CL’s, structures (unfertilised ova plus embryos) and
(p < 0.01) embryos recovered. A significantly (p < 0.01) higher number of unfertilised ova
were observed from the one shot FSH plus eCG group (4.06
±
0.9), compared to the multiple
FSH group (0.24
±
0.1). However, the number of degenerated embryos was not affected
by treatment. The total number of transferable embryos was significantly lower in the one
shot FSH plus eCG protocol (0.22
±
0.2), compared to the multiple FSH protocol (9.56
±
1.9).
The size of follicles was not affected by treatment, however the total number of follicles
at CIDR removal was significantly lower in the one shot FSH plus eCG group (11.67
±
0.7),
compared to the multiple FSH group (14.83
±
0.7). AI might have been performed at the
wrong time, because of the duration of the oestrous period being longer in Group 2. The
multiple FSH superovulation protocol overall seemed to be more efficient in the Boer goat.
More research is needed on the doses of gonadotrophins administered and the time of AI,
in order for the simplified protocol (Group 2) to be effective.
