FOUR TRIALS WERE CONDUCTED AT THE UFSâS
EXPERIMENTAL FARM TO EVALUATE, AND DEVELOP
A MORE EFFICIENT PROTOCOL FOR
SUPEROVULATION AND EMBRYO
CRYOPRESERVATION AND TRANSFER METHODS IN
BOER GOATS. EACH TRIAL WAS CONDUCTED WITH
SPECIFIC OBJECTIVES. THE FIRST TWO TRIALS WERE
CONDUCTED DURING THE AUTUMN AND SPRING
SEASONS OF 2005, TO EVALUATE THE OVARIAN
RESPONSE OF BOER GOAT DOES TO
SUPEROVULATION AND EMBRYO RECOVERY
PROCEDURES FOLLOWING A PRE-TREATMENT WITH
A GNRH AGONIST. FURTHER ALSO TO EVALUATE THE
EFFECT OF SEASON ON THE OVARIAN RESPONSE TO
SUPEROVULATION. TWENTY-ONE MULTIPAROUS
MATURE BOER GOAT DOES WERE USED AS DONORS
DURING THE NATURAL BREEDING SEASON
(AUTUMN). IN ALL DOES, THE ONSET OF THE
OESTRUS WAS SYNCHRONISED WITH CIDRâS
INSERTED INTRAVAGINALLY FOR A PERIOD OF 17
DAYS. DOES WERE ALL SUPEROVULATED WITH 200 MG PFSH/DOE ADMINISTERED I.M. IN 7 DOSAGES, AT
12H INTERVALS, STARTING 48H PRIOR TO CIDR
REMOVAL. THE TREATMENT GROUP RECEIVED A
GNRH AGONIST (GNRHA) (40μG/DAY/DOE)
TREATMENT, ADMINISTERED AS 2 INJECTIONS PER
DAY FOR 7 DAYS, STARTING ON DAY 8 OF CIDR
INSERTION. THE CONTROL DOES WERE
SYNCHRONISED AND SUPEROVULATED, BUT
RECEIVED NO GNRHA.
OESTROUS DETECTION WAS PERFORMED TWICE
DAILY PRIOR TO PROGESTAGEN TREATMENT (CIDR
APPLICATION) AND AT 8H INTERVALS FOLLOWING
CIDR REMOVAL FOR A PERIOD OF 72H. FIXED-TIME
LAPAROSCOPIC AI WITH DILUTED BOER GOAT SEMEN
WAS PERFORMED 36 AND 48H FOLLOWING CIDR
REMOVAL. BLOOD SAMPLES WERE ALSO COLLECTED
FROM 5 ANIMALS IN EACH GROUP AT 4 DAY
INTERVALS DURING PROGESTAGEN TREATMENT AND
AT DAY 14 OF PROGESTAGEN TREATMENT TO
EVALUATE THE HORMONAL EFFECT OF GNRHA
TREATMENT. FROM SUPEROVULATION TREATMENT
UNTIL CIDR REMOVAL, BLOOD SAMPLES WERE
COLLECTED TWICE DAILY AND THEN AT 8H
INTERVALS FROM CIDR REMOVAL FOR A PERIOD OF 3
DAYS. THE BLOOD SAMPLES WERE ALSO TAKEN AT
24 H INTERVALS FOLLOWING THE SECOND AI UNTIL
EMBRYO FLUSHING (DAY 6 FOLLOWING AI). SERUM
PROGESTERONE AND OESTROGEN CONCENTRATIONS
WERE DETERMINED VIA RADIOIMMUNOASSAY.
EMBRYOS WERE THEN FINALLY SURGICALLY
RECOVERED (DAY 6) UNDER GENERAL ANAESTHESIA.
THE OESTROUS SYNCHRONISATION RESPONSE WAS
EVALUATED BASED ON THE OCCURRENCE OF
OESTRUS, TIME TO ONSET OF OESTROUS AND
DURATION OF THE INDUCED OESTROUS PERIOD. THE
EMBRYO YIELD AND QUALITY WAS ALSO
EVALUATED. ONLY 81% OF THE DOES EXHIBITED OVERT SIGNS OF
OESTRUS PRIOR TO SYNCHRONISATION TREATMENT
APPLICATION (INDICATION OF CYCLIC ACTIVITY).
THE MEAN DURATION OF THESE NATURAL OESTROUS
CYCLES WAS RECORDED AS 20.1±3.5D, WHILE THE
NATURAL OESTROUS PERIOD LASTED FOR 37.7±11.9H.
FOLLOWING SYNCHRONISATION AND
SUPEROVULATION TREATMENT, 100% AND 80% OF
THE DOES IN THE FSH/GNRHA AND FSH-TREATED
DOES SHOWED SIGNS OF OESTRUS, RESPECTIVELY.
THE TIME INTERVAL FROM CIDR REMOVAL TO ONSET
OF OESTRUS AND DURATION OF THE INDUCED
OESTROUS PERIOD DID NOT DIFFER SIGNIFICANTLY,
ALTHOUGH THE DURATION OF THE INDUCED
OESTROUS PERIOD IN THE FSH/GNRHA GROUP
(19.6±5.5H) TENDED TO BE SHORTER, COMPARED TO
THE FSH-TREATED DOES (25.0±7.4H). THE
OCCURRENCE OF ABNORMAL CLâS WAS 38.1% IN
TOTAL, WHILE 23.8% OF THE DOES DID NOT HAVE
ANY CLâS. THERE WERE NO SIGNIFICANT
DIFFERENCES IN EMBRYO YIELD AND QUALITY
PARAMETERS MEASURED. IN DOES PRE-TREATED
WITH GNRHA HOWEVER, THE NUMBER OF
DEGENERATE EMBRYOS TENDED TO BE HIGHER,
WHILE THE NUMBER OF TRANSFERABLE EMBRYOS
TENDED TO BE LOWER, COMPARED TO THE CONTROL
(FSH) DOES (6.6±4.2 VS. 1.7±1.5 AND 3.4±2.7 VS. 9.3±6.1,
RESPECTIVELY).
THE SECOND TRIAL REPEATING ALL THE
PROCEDURES PERFORMED IN THE FIRST TRIAL WAS
CONDUCTED IN THE SPRING OF 2005 (OUTSIDE THE
BREEDING SEASON), USING 22 MULTIPAROUS BOER
GOAT DOES AS RECIPIENTS. ONLY 45.5% OF THE DOES
SHOWED OVERT SIGNS OF OESTRUS PRIOR TO THE
APPLICATION OF OESTROUS SYNCHRONISATION AND
SUPEROVULATION TREATMENT. GNRHA TREATMENT
HAD NO BENEFICIAL EFFECT IN RESPONSE TO OESTROUS SYNCHRONISATION AND OVULATION
RATE. THE TOTAL MEAN STRUCTURES FLUSHED WAS
SIGNIFICANTLY (P<0.05) LOWER IN THE DOES PRETREATED
WITH GNRHA (12.6±6.0 PER DOE, COMPARED
TO THE CONTROL DOES (17.6±4.9 PER DOE). THE MEAN
TOTAL NUMBER OF EMBRYOS COLLECTED PER
DONOR AND THE FERTILISATION RATE WERE
SIGNIFICANTLY (P<0.05) LOWER IN DOES PRETREATED
WITH GNRHA THAN IN THE FSH-TREATED
DOES (11.5.±5.3 VS. 16.5±6.1 AND 81.6±32.2% VS.
92.6±19.5%, RESPECTIVELY). GNRHA TREATMENT HAD
NO EFFECT ON THE MEAN NUMBER OF UNFERTILISED
OVA PER DONOR. PRE-TREATMENT OF DOES WITH
GNRHA HOWEVER RESULTED IN A SIGNIFICANTLY
(P<0.01) HIGHER MEAN NUMBER OF DEGENERATIVE
EMBRYOS WHEN COMPARED TO THE CONTROL DOES
(6.9±4.5 VS. 3.2±4.2 PER DOE). SUBSEQUENTLY, THE
NUMBER OF TRANSFERABLE EMBRYOS AND
TRANSFERABLE RATE (4.3±4.0 AND 32.7±26.9%) WAS
LOWER IN DOES PRE-TREATED WITH GNRHA,
COMPARED TO THE CONTROL DOES (13.1±5.3 AND
75.2±26.8%). THE MEAN TIME TO ONSET OF OESTRUS
WAS SIGNIFICANTLY (P<0.05) EARLIER DURING THE
NATURAL BREEDING SEASON (24.9±4.8H), COMPARED
TO OUTSIDE THE BREEDING SEASON IN DOES
(30.5±9.1H). SIMILARLY, THE MEAN DURATION OF THE
INDUCED OESTRUS WAS SIGNIFICANTLY (P<0.05)
LONGER DURING THE NATURAL BREEDING SEASON
(24.0±5.7H) - THAN OUTSIDE THE BREEDING SEASON
(18.2±3.7H). SEASON DID NOT HAVE ANY SIGNIFICANT
EFFECT ON THE TOTAL NUMBER OF CLâS INDUCED,
ALTHOUGH THE NUMBER OF CLâS ON THE RIGHT
OVARY WAS SIGNIFICANTLY (P<0.05) LOWER DURING
THE NATURAL BREEDING SEASON. SEASON DID NOT
HAVE EFFECT ON THE NUMBER OF STRUCTURES
RECOVERED, EMBRYOS, DEGENERATIVE AND
TRANSFERABLE EMBRYOS PER DONOR. THE MEAN NUMBER OF UNFERTILISED OVA PER DONOR (3.3±2.8)
WAS SIGNIFICANTLY (P<0.05) HIGHER IN GOATS
TREATED OUTSIDE THE NATURAL BREEDING SEASON
THAN DURING THE NATURAL BREEDING SEASON
(0.9±2.4).
IT COULD BE CONCLUDED THAT PRE-TREATMENT
WITH GNRHA DOES NOT HAVE ANY BENEFICIAL
EFFECT ON OESTROUS RESPONSE, TIME TO ONSET
AND DURATION OF THE INDUCED OESTROUS PERIOD.
THE ADDITION OF THE GNRHA INTO THE FSH GOAT
SUPEROVULATION PROTOCOL REDUCED THE
NUMBER OF STRUCTURES RECOVERED, EMBRYO
YIELD, AND THE FERTILISATION RATE (THE NUMBER
OF EMBRYOS PER STRUCTURES ON OVARIES). THE
PRE-TREATMENT WITH GNRHA ALSO INCREASED THE
NUMBER OF DEGENERATE EMBRYOS - WHICH
ULTIMATELY REDUCED THE TOTAL NUMBER OF
TRANSFERABLE EMBRYOS. IT COULD THUS BE
RECOMMENDED THAT A PRE-TREATMENT WITH A
GNRH AGONIST IN A BOER GOAT MOET PROGRAMME
IS NOT WARRANTED. THE SERUM PROGESTERONE
CONCENTRATIONS DID NOT DIFFER BETWEEN THE
TREATMENT GROUPS, THROUGHOUT THE OESTROUS
SYNCHRONISATION PERIOD. AT 48H FOLLOWING THE
SECOND AI (96H AFTER CIDR REMOVAL), THE
CONTROL DOES RECORDED A SIGNIFICANTLY (P<0.05)
HIGHER MEAN SERUM PROGESTERONE
CONCENTRATION (11.3±4.9 NG/ML), THAN IN THE
FSH/GNRHA-TREATED DOES (4.3±2.1 NG/ML). THE
SERUM PROGESTERONE CONCENTRATIONS
INCREASED FOLLOWING THE SECOND AI AND WERE
HIGHEST ON THE DAY OF EMBRYO FLUSHING IN
BOTH GROUPS â WITHOUT ANY SIGNIFICANT
DIFFERENCES. THE MEAN SERUM OESTROGEN
CONCENTRATION WAS SIGNIFICANTLY (P<0.05)
HIGHER ON DAY 12 OF SYNCHRONISATION (5TH DAY
OF GNRHA TREATMENT) AND AT THE 4TH PFSH (SUPEROVULATION) INJECTION IN THE FSH/GNRHA
TREATED GROUP COMPARED TO THE CONTROL DOES.
AT THE TIME OF THE FIRST AI (36H FOLLOWING CIDR
REMOVAL) THE MEAN SERUM OESTROGEN
CONCENTRATION WAS SIGNIFICANTLY (P<0.05)
HIGHER (58.3±26.9 PG/ML) IN THE CONTROL (FSHSTIMULATED)
DOES, COMPARED TO THE FSH/GNRHATREATED
DOES (15.7±17.4 PG/ML). THE BLOOD
HORMONAL LEVELS INDUCED DURING
SUPEROVULATION WERE DEPENDENT ON VARIOUS
OVARIAN FACTORS WHICH ULTIMATELY DETERMINE
THE COMPETENCE OF THE OOCYTES AND
EVENTUALLY VIABILITY OF THE EMBRYOS.
A THIRD TRIAL WAS CONDUCTED DURING THE
NATURAL BREEDING SEASON (AUTUMN, 2006).
SEVENTEEN MULTIPAROUS MATURE BOER GOAT
DOES WERE USED AS DONORS IN THIS TRIAL TO
EVALUATE AND REFINE THE FSH SUPEROVULATORY
TREATMENT BY COMPARING TWO ROUTES OF
GONADOTROPHIN (PFSH) ADMINISTRATION. HERE 27
RECIPIENTS WERE USED TO EVALUATE THE
SURVIVAL RATE OF THE GOAT EMBRYOS FOLLOWING
CRYOPRESERVATION USING THE CONVENTIONAL
SLOW FREEZING OR VITRIFICATION METHOD. DOES
RECEIVED A PFSH SUPEROVULATION TREATMENT
INTRAMUSCULAR OR SUBCUTANEOUS, WHILE
RECIPIENTS RECEIVED FRESH, SLOW FROZENTHAWED
OR VITRIFIED-THAWED EMBRYOS. THE
ROUTE OF ADMINISTERING GONADOTROPHIN
TREATMENT DID NOT AFFECT THE OESTROUS
RESPONSE, THE TIME FROM CIDR REMOVAL TO THE
ONSET OF OESTRUS AND DURATION OF THE INDUCED
OESTROUS PERIOD. THE ROUTE OF GONADOTROPHIN
ADMINISTRATION DID NOT AFFECT THE OVULATION
RATE, THE TOTAL NUMBER OF STRUCTURES,
NUMBER OF EMBRYOS AND TRANSFERABLE
EMBRYOS COLLECTED PER DONOR. THE MEAN NUMBER OF UNFERTILISED OVA IN THE I.M. GROUP
(3.3±4.8) WAS SIGNIFICANTLY (P<0.05) HIGHER, THAN
IN THE S.C. GROUP (0.3±0.8). SIMILARLY, THE MEAN
NUMBER OF DEGENERATED EMBRYOS PER DONOR IN
THE DOES ADMINISTERED THE FSH
SUBCUTANEOUSLY (5.9±4.5) WAS SIGNIFICANTLY
(P<0.05) HIGHER, WHEN COMPARED TO THE
INTRAMUSCULAR GROUP (2.6±2.3). A TOTAL OF 88.9%
RECIPIENTS DEMONSTRATED SIGNS OF OESTRUS
FOLLOWING CIDR REMOVAL. A PREGNANCY RATE OF
85.7%, 50.0% AND 37.5% WAS RECORDED FOLLOWING
THE TRANSFER OF FRESH, SLOW-FROZEN AND
VITRIFIED EMBRYOS, RESPECTIVELY. EMBRYO
SURVIVAL RATES OF 35.7%, 25.0% AND 31.3% WERE
THEN EVENTUALLY RECORDED FOLLOWING FRESH,
SLOW-FROZEN AND VITRIFIED EMBRYO TRANSFER. IT
COULD THUS BE CONCLUDED THAT AN ADVANTAGE
OF THE SUBCUTANEOUS ROUTE OF ADMINISTRATION
RESULTED IN A LOWER NUMBER OF UNFERTILISED
OVA RECOVERED, WHICH WAS HOWEVER NEGATED
BY A HIGHER NUMBER OF DEGENERATE EMBRYOS
RECORDED. THEREFORE BOTH ROUTES CAN BE USED
FOR THE ADMINISTRATION OF PFSH
SUPEROVULATION TREATMENT IN BOER GOAT DOES
DURING THE BREEDING SEASON. A RELATIVELY
HIGH PREGNANCY RATE WAS OBTAINED FOLLOWING
THE TRANSFER OF FRESH EMBRYOS. HOWEVER, THE
SURVIVAL RATE OF EMBRYOS FOLLOWING EITHER
FRESH, SLOW FROZEN-THAWED OR VITRIFIEDTHAWED
EMBRYOS WAS UNSATISFACTORY. MORE
RESEARCH IS THUS WARRANTED, WITH A HIGHER
NUMBER OF ANIMALS, DIRECTED AT IMPROVING THE
SURVIVABILITY OF EMBRYOS FOLLOWING FRESH
AND CRYOPRESERVED GOAT EMBRYO TRANSFER.
THE FOURTH TRIAL WAS CONDUCTED DURING THE
NATURAL BREEDING (AUTUMN, 2007). DONOR DOES
WERE SUPEROVULATED FOLLOWING A LONG (17 DAY) PROGESTAGEN SYNCHRONISATION PROTOCOL,
WITH OR WITHOUT PROSTAGLANDIN-F2Î OR
SUPEROVULATED FOLLOWING A PREDETERMINED
TIME OF OVULATION (DAY 0 PROTOCOL). RECIPIENT
DOES RECEIVED FROZEN-THAWED OR FRESH BOER
GOAT EMBRYOS FOLLOWING OESTROUS
SYNCHRONISATION USING DIFFERENT PROTOCOLS.
DURING THE SYNCHRONISATION TREATMENT PRIOR
TO SUPEROVULATION ONLY 71.4% OF THE DOES IN
THE DAY 0 PROTOCOL EXHIBITED SIGNS OF OESTRUS,
WHILE ONLY ONE DOE EXHIBITED SIGNS OF OESTRUS
FOLLOWING SUPEROVULATION. ALL DOES SHOWED
OVERT SIGNS OF OESTRUS FOLLOWING LONG
PROGESTAGEN TREATMENT WITH OR WITHOUT
ADMINISTRATION OF PROSTAGLANDIN-F2Î. ALL
DOES ALSO DEMONSTRATED A SIMILAR RESPONSE
TIME FROM CIDR REMOVAL TO THE ONSET OF
OESTRUS AND THE DURATION OF THE INDUCED
OESTROUS PERIOD. THE DAY 0 PROTOCOL RESULTED
INTO A SIGNIFICANTLY (P<0.01) LOWER TOTAL
NUMBER OF CLâS (4.0±3.5) PER DOE - COMPARED TO
GROUP 2 (17-DAY PROGESTAGEN TREATMENT PLUS
PGF2Î) (14.5±4.6) AND GROUP 3 (17-DAY
PROGESTAGEN TREATMENT) (16.5±5.9). THE MEAN
NUMBER OF STRUCTURES RECOVERED FROM GROUP
1 (1.4±0.5) WAS SIGNIFICANTLY (P<0.05) LOWER,
COMPARED TO GROUP 3 (11.4±7.3). THIS MEAN IN THE
DAY 0 GROUP HOWEVER DID NOT DIFFER
SIGNIFICANTLY, WHEN COMPARED TO GROUP 2
(8.4±7.7). THE VARIATION RECORDED BETWEEN
ANIMALS IN THE GROUP 2 WAS VERY HIGH. THE DAY
0 PROTOCOL RESULTED IN A SIGNIFICANTLY (P<0.01)
LOWER MEAN NUMBER OF EMBRYOS BEING
RECORDED. HOWEVER, THE MEAN NUMBER OF
UNFERTILISED OVA AND DEGENERATING EMBRYOS
WAS SIMILAR FOR ALL THE TREATMENT GROUPS.
THE DAY 0 (GROUP 1) GROUP RESULTED IN THE COLLECTION OF ONLY ONE EMBRYO, WHICH WAS
ALSO TRANSFERABLE, BUT DUE TO THE SINGLE
VALUE THIS DATA WAS NOT ANALYSED. THE
ADDITION OF PROSTAGLANDIN-F2Î HAD NO EFFECT
ON THE FERTILISATION RATE AND THE MEAN
NUMBER OF TRANSFERABLE EMBRYOS RECORDED
BETWEEN GROUP 2 AND 3.
THE TIME INTERVAL FROM CIDR REMOVAL TO THE
ONSET OF OESTRUS IN THE ADULT DOES WAS
SIGNIFICANTLY (P<0.01) SHORTER THAN THAT
RECORDED IN THE YOUNG DOES. HOWEVER, AGE DID
NOT HAVE ANY SIGNIFICANT EFFECT ON THE
DURATION OF THE INDUCED OESTROUS PERIOD. THE
MEAN NUMBER OF CLâS, STRUCTURES AND EMBRYOS
RECOVERED WERE HOWEVER SIGNIFICANTLY
(P<0.01) HIGHER IN THE ADULT DOES. NO RECOVERY
OF UNFERTILISED OVA WAS RECORDED IN THE
YOUNG DOES AND THE FERTILISATION RATE AND
MEAN NUMBER OF UNFERTILISED OVA DID NOT
DIFFER BETWEEN THE YOUNG AND ADULT DOES.
SIMILARLY THE AGE OF THE DOE HAD NO EFFECT ON
THE MEAN NUMBER OF DEGENERATE EMBRYOS PER
DONOR RECORDED. THE MEAN NUMBER OF
TRANSFERABLE EMBRYOS PRODUCED IN THE ADULT
DOES (15.8±6.4) WAS SIGNIFICANTLY (P<0.01) HIGHER,
THAN IN THE YOUNG DOES (9.5±3.7).
THE TIME FROM CIDR REMOVAL TO THE ONSET OF
OESTRUS WAS NOT AFFECTED BY REPEATED
SUPEROVULATION TREATMENT. DOES
SUPEROVULATED FOR THE FIRST TIME SHOWED A
SIGNIFICANTLY (P<0.05) SHORTER MEAN DURATION
OF OESTRUS (20.8±10.1H), WHEN COMPARED TO
THOSE REPEATEDLY SUPEROVULATED (30.4±6.7 H).
REPEATED SUPEROVULATION DID NOT SHOW AN
EFFECT ON THE TOTAL NUMBER OF CLâS PRODUCED
PER DOE. HOWEVER, THE MEAN NUMBER OF
STRUCTURES RECOVERED WAS SIGNIFICANTLY (P<0.05) LOWER IN THE REPEAT-TREATED DOES
(6.0±8.7), COMPARED TO DOES SUPEROVULATED FOR
THE FIRST TIME (11.7±5.0). SIMILARLY, THE MEAN
NUMBER OF EMBRYOS RECOVERED PER DOE WAS
SIGNIFICANTLY (P<0.05) HIGHER IN DOES
SUPEROVULATED FOR THE FIRST TIME. THE MEAN
NUMBER OF UNFERTILISED OVA PER DONOR WAS
ALSO SIGNIFICANTLY (P<0.05) HIGHER IN THE
REPEATEDLY-TREATED DOES (5.5±7.8), COMPARED TO
THE 0.1±0.3 FOR DOES SUPEROVULATED FOR THE
FIRST TIME. THIS RESULTED IN A SIGNIFICANTLY
(P<0.05) LOWER FERTILISATION RATE BEING
OBTAINED IN THE REPEATEDLY-TREATED DOES
(50.0±70.7%), COMPARED TO DOES SUPEROVULATED
FOR THE FIRST TIME (99.4±1.9%). THE MEAN NUMBER
OF DEGENERATE EMBRYOS DID NOT DIFFER
SIGNIFICANTLY BETWEEN THESE GROUPS. THE
NUMBER OF TRANSFERABLE EMBRYOS RECORDED
WAS SIGNIFICANTLY (P<0.05) LOWER IN THE
REPEATEDLY TREATED DOES (3.8±8.5), COMPARED TO
THEIR COUNTERPARTS (10.7±4.0).
IN GROUP A (CIDR + PGF2Î + ECG; CHRONOGEST)
88.9% OF THE DOES RESPONDED TO OESTROUS
SYNCHRONISATION. ALL DOES IN GROUP B (CIDR
+ECG; FOLLIGON) AND GROUP C (CIDR + ECG;
CHRONOGEST) EXHIBITED SIGNS OF OESTRUS
FOLLOWING OESTROUS SYNCHRONISATION. DOES
FROM GROUP A (42.0±3.7 H) EXHIBITED A LONGER
(P<0.05) TIME INTERVAL FROM CIDR WITHDRAWAL
TO THE ONSET OF OESTRUS, COMPARED TO GROUP C
DOES (32.0±8.6H). THERE WAS HOWEVER, NO
SIGNIFICANT DIFFERENCE WITH RESPECT TO THE
TIME INTERVAL FROM CIDR REMOVAL TO THE ONSET
OF OESTRUS BETWEEN GROUP A AND B. GROUP B
AND C DOES ALSO RECORDED A SIMILAR RESPONSE
TIME FROM CIDR WITHDRAWAL TO THE ONSET OF
OESTRUS. THE DURATION OF THE INDUCED OESTROUS PERIOD BEING SIGNIFICANTLY (P<0.05)
SHORTER IN GROUP B (19.0±13.5H), WHEN COMPARED
TO GROUP A (39.0±15.1H). NO SIGNIFICANT
DIFFERENCE WAS RECORDED BETWEEN GROUP B
AND C REGARDING THE DURATION OF THE INDUCED
OESTROUS PERIOD. IT COULD THUS BE CONCLUDED
THAT THE POOR OVARIAN RESPONSE TO THE
SUPEROVULATORY TREATMENT IN THE GROUP 1
(DAY 0 PROTOCOL) WARRANTS FURTHER RESEARCH
WHICH WILL HAVE TO FOCUS ON THE
SYNCHRONISATION OF OVULATION AND AN
APPROPRIATE TIME FOR INITIATING A
SUPEROVULATORY TREATMENT IN THIS PROTOCOL.
THE ADDITION OF A PROSTAGLANDIN-F2Î
TREATMENT IN THE SUPEROVULATORY PROTOCOL
FOLLOWING A LONG PROGESTAGEN
SYNCHRONISATION TREATMENT IN BOER GOAT DOES
ALSO HAS NO REAL ADVANTAGE. THE TIME OF
PROSTAGLANDIN ADMINISTRATION AND THE
DOSAGE USED COULD HAVE CONTRIBUTED TO THE
OBSERVED RESULTS.
THE AGE OF THE DONOR DOE HAS BEEN SHOWN TO
HAVE A MAJOR EFFECT ON THE OVARIAN ACTIVITY
FOLLOWING SUPEROVULATION TREATMENT.
ALTHOUGH THE YOUNG DOES RECORDED AN
ACCEPTABLE FERTILISATION RATE, THE NUMBER OF
TRANSFERABLE EMBRYOS WAS HOWEVER LOWER.
THEREFORE, IF A LARGE NUMBER OF ACCEPTABLE
EMBRYOS (THE MAXIMUM) ARE REQUIRED IN A
MOET PROGRAMME, IT IS MORE APPROPRIATE TO
SUPEROVULATE MULTIPAROUS MATURE GOATS.
THIS WILL LEAD TO THE PRODUCTION OF MORE
TRANSFERABLE EMBRYOS. THE NUMBER OF TIMES
THAT A DONOR CAN BE UTILISED IN A BOER GOAT
MOET PROGRAMME SEEM IS TO BE LIMITED TO
THREE TIMES DUE TO REDUCTION IN THE NUMBER OF
STRUCTURES AND EMBRYOS BEING RECOVERED FROM THE 4TH TIME REPEATEDLY TREATED DOES.
MOREOVER, THE NUMBER OF UNFERTILISED OVA
INCREASED FOLLOWING REPEATED
SUPEROVULATION, HENCE REDUCING THE
FERTILISATION RATE AND EVENTUALLY THE
NUMBER OF TRANSFERABLE EMBRYOS.
THE THREE PROTOCOLS USED FOR OESTROUS
SYNCHRONISATION IN RECIPIENTS WERE EFFICIENT
IN SYNCHRONISING OESTRUS. THE PREGNANCY RATE
OBTAINED WAS GENERALLY LOW IN ALL THE
TREATMENT GROUPS AND POSSIBLE INTERACTIONS
THUS COMPLICATE THE MAKING OF ANY DEFINITE
RECOMMENDATIONS.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-08222008-083707 |
| Date | 22 August 2008 |
| Creators | Lehloenya, Khoboso Christina |
| Contributors | Dr LMJ Schwalbach, Dr S Grobler, Prof JPC Greyling |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-08222008-083707/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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