PhD

The objective of the study was to compare the superovulatory response
and viability of embryos in peripubertal and adult Malabari goats.
Nineteen peripubertal and eighteen adult Malabari goats were selected
and utilised for the study. Animals of each age group were at random allotted to
sub groups GI, G2 and G3 consisting of six animals, except GI of peripubertal
goats, which contained seven. The animals in each age group were subjected to
three superovulation protocols i.e., oFSH @ 0.9 units/kg body weight (01), oFSH
@ 0.45 unitslkg body weight (G2) and pFSH @ 2 mglkg body weight (G3) as six
injections after synchronising the oestrus using 1.5 mg norgestomet ear implant
and PGF2u (GI and G2) and norgestomet ear implant alone (G3). On exhibition
of heat signs animals were bred or inseminated and hCG was administered @ 500
IV and 750 IV in peripubertal and adult goats respectively. The serum glucose,
LDH, ACP, ALP, and P4 were estimated. Peripubertal and adult goats belonging
to G3 were supported with P4 injection @ 20 mg and 25 mg respectively twice
daily from day four to day of embryo collection.
The embryos were collected six to eight days after breeding using uterine
flushing technique. Thirty two good quality embryos (16 morulae and 16
blastocysts) each from peripubertul and adult goats were frozen by slow freezing
technique using EG as cryoprotectant. The quality of frozen thawed embryos was
assessed morphologically and transferable frozen thawed b.lastocysts from each
age group were subjected to in vitro culture. A total of nine transferable frozen
thawed morulae each from peripubertal and adult goats were transferred into the
uterus of three synchronous recipients and P4 levels at weekly intervals were
assessed up to day 28.
The overall response to synchronisation (percentage) was almost same in
peripubertal and adult goats (94.74 vs 94.45). The overall mean interval from

end of synchronisation to heat and duration of heat did not show any significant
difference between these age groups. The overall mean intensity of heat (score)
was slightly more in peripubertal goats (3.44 ± 0.15 vs 3.18 ± 0.21).
A decreasing trend was observed in the average number of anovulatory
follicles and in superovulatory response from GJ to G3 both in peripubertal and
adult goats. While a significant difference (P<0.05) in SOR was observed
between GJ and G3 in peripubertal goats, no such variation could be noted
between different groups in adult goats. The overall average superovulatory
response (8.16 ± 0.84 and 12.30 ± 1.40) and SOR in G2 (6.96 ± 1.45 and 14.30 ±
2.60) showed a significant difference (P<0.05) between peripubertal and adult
goats. As a result of high incidence of PRCL (50% vs 52%) the embryo recovery
rate was low from both the age groups.
The overall percentage ova and embryo recovery and fertilized ova
recovery rates were higher in peripubertal goats (45.51 vs 36.48 and 88.73 vs
74.07), while overall average values of these parameters were found to be almost
equal in both these age groups (3.94 vs 4.50 and 3.32 vs 3.33). In peripubertal
and adult goats in G3 which were supported with exogenous progesterone, the
percentage embryo recovery rate was 15 and 46.15 respectively as against 39.06
and 34.42 in nontreated groups. The overall percentage (average) transferable
embryo recovery in peripubertal and adult goats were 95.23 and 95 (3.15 and
3.17) respectively.
The developmental stages of embryos collected from peripubertal and
adult goats were almost similar on sixth day (l00% morulae vs. 96.30% morulae
and 3.70% blastocysts) and eighth day (all blastocysts). But on seventh day more
advanced stages (morulae and blastocysts) could be recovered from peripubertal
goats than adult animals.
Out of 30 embryos recovered after freezing, 73.33 per cent were of
transferable quality in peripubertal goats, while, it was 70 per cent in adult goats.

Both in peripubertal and adult goats, blastocysts were more resistant to freezing
than morulae (64.29% Vs 81.25% and 60 % Vs 80%). On in vitro culture of the
frozen blastocysts from peripubertal goats 53.84 per cent showed development
while in adult goats it was only 50 per cent. Pregnancy rate in recipient goats on
transfer of frozen morulae from peripubertal and adult goats were found to be
equal (66.67%) on day 21 while it was 33.33 per cent on day 28 as diagnosed by
progesterone assay.
The overall values of serum glucose, LDH, ACP and ALP did not show
any significant difference between peripubertal and adult goats on the day of
superovulatory heat. The mean serum progesterone (ng/rnl) on day of
superovulatory heat in peripubertal and adult goats were 0.38 ± 0.03 and 0.32 ±
0.05 respectively. A negative correlation was observed between P4 level during
superovulatory heat and number of FCL, PRCL, total superovulatory response
(significant in peripubertal goats (P<0.01)) and transferable embryo recovery.
The serum P4 level (ng/ml) on day of embryo collection was low in
animals with PRCL and it ranged from 0.8 to 22.20 and 0.8 to 30.50 In
peripubertal and adult goats respectively. In P4 supported animals the level was
> 30.70 ng/rnl.
A significant positive correlation (P on day of embryo collection and number of FCL and transferable embryo
recovery, both in peripubertal and adult goats. While P4 profile on day of embryo
collection and number of PRCL showed a significant negative correlation in both
these age groups (P level on day 21 and 28 was higher cornpared.to non-pregnant animals.
The study revealed that peripubertal Malabari goats are as suitable as
adult goats for MOET programme.