TY - BOOK AU - Metilda Joseph AU - Vijayakumaran V (Guide) TI - Comparative study on superovulatory response and viability of embryos in peripubertal and Malabari Goats U1 - 636.082 PY - 2003/// CY - Mannuthy PB - Department of Animal Reproduction, College of Veterinary and Animal Sciences N2 - 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