Effect of Different Synchronisation Protocols on Embryo Transfer in Sahiwal Cows

The present study was conducted to compare CIDR + Ovsynch, Double PG protocol’s synchronisation effect on recipient cows after IVF-ET (Invitro Fertilization - Embryo Transfer). Since there is a positive effect of synchronisation on conception rate, protocol with higher synchronisation efficiency and conception rate can be determined under this study. Invitro Fertilization technology increases the genetic gain by reducing the generation interval. It helps to utilize a female cattle genetic potential fully and produce greater number of embryos in short duration with utilization of less semen. In vitro Production of embryos can be used to produce genetically proven animals with a good performance for improving dairy production. 85 animals were selected randomly and assigned into 3 groups. Group 1 (CIDR+ Ovsynch), Group 2 (Double PG) and Group 3 (control). Embryo transfers were done into these recipient cows by using nonsurgical method after day 7 of estrus by depositing the embryos in cranial or middle third of uterine horn on ipsilateral side of ovary having CL. The estrus response rates, overall conception rate and cervical transfer scores were found to be 60.60%,18.75% and 66.67 % in CIDR+ Ovsynch protocol, 60.00%,15.78% and 16.67 % in Double PG protocol, 58.33%, 0% and 16.67 % in natural estrus in recipient cows. The mean BCS and mean CL diameter was 3.07 ± 0.13 and 21.56±1.13 mm, 2.53 ± 0.07 and 14.90±0.59 in pregnant and non pregnant recipients respectively. Conception rate was found higher in animals having vacuolated CL (18.18%) when compared to animals having Compact CL (13.79%) and those receiving Expanded blastocyst (23.80%) than blastocyst (5.26%) when the transport time was within 3hrs (19.04%) when compared to 5-7hrs (10.52%). Overall, higher synchronisation, eligible animals for transfer and conception rates were observed with timed ET in CIDR + Ovsynch protocol than in Double PG and natural estrus animals.