Abstract
Seventeen Boer goat does were used in this study to compare the effect of an intramuscular
or subcutaneous route of administrating a superovulation treatment during the natural
breeding season (autumn). The oestrous cycles of all does were synchronised for 17 days
using CIDR dispensers and superovulated with pFSH administered in 7 dosages, at 12 h
intervals—initiated 48 h prior to CIDR removal. Does were teased to test for the onset of
oestrus at 8 h intervals, starting at CIDR removal. All does were cervically inseminated
with fresh undiluted Boer goat semen at a fixed time (36 h and 48 h), following CIDR withdrawal.
Embryos were surgically flushed on day 6 following the second AI, evaluated and
classified according to their morphological appearance. The route of gonadotrophin (pFSH)
administration had no effect on the response to oestrous synchronisation. The number of
ovulations, structures and embryos recovered and fertilisation rate were also similar via
both routes of gonadotrophin administration. The number of unfertilised ova per donor on
the other hand, was significantly higher in does administered pFSH using the intramuscular
(3.3±4.8), rather than the subcutaneous route (0.3±0.8). However, the number of
degenerated embryos was higher when pFSH was administered subcutaneously (5.9±4.5),
compared to intramuscularly (2.6±2.3). The overall number of transferable embryos was
not affected by the route of gonadotrophin administration. The subcutaneous route of
gonadotrophin administration led to a lower number of unfertilised ova, this beneficial
effect was negated by an increase in the number of degenerate embryos—resulting in both
routes of administration leading to a similar number of transferable embryos. Although
no significant differences were found between subcutaneous and intramuscular routes of
gonadotrophin administration regarding the number of transferable embryos, the subcutaneous
route resulted in lower variances which may indicate a more predictable response.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:tut/oai:encore.tut.ac.za:d1001677 |
| Date | 17 November 2009 |
| Creators | Lehloenya, KC, Greyling, JPC |
| Publisher | Elsevier |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | |
| Rights | © 2009 Elsevier B.V. |
| Relation | Small Ruminant Research |
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