AUTHOR=Abulaiti Adili , El-Qaliouby Hadeel S. , El Bahgy Halla E. K. , Naseer Zahid , Ahmed Zulfiqar , Hua Guohua , Yang Liguo 

TITLE=GPGMH, a New Fixed Timed-AI Synchronization Regimen for Swamp and River Crossbred Buffaloes (Bubalus bubalis)

JOURNAL=Frontiers in Veterinary Science

VOLUME=Volume 8 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.646247

DOI=10.3389/fvets.2021.646247

ISSN=2297-1769

ABSTRACT=The crossbreeding of (swamp × river) buffalo breeds is practiced for the improvement of milk yield and reproductive performance in swamp buffalo herds. This study aimed to modify the Ovsynch synchronization protocol (GPG) and improve FTAI for better reproductive performance of crossbred buffaloes. Comparison of four conventional synchronization protocols (PmPG), (GPG), (PGPE) and (P4PmPG) in crossbred buffaloes showed that the GPG protocol treated buffaloes displayed higher (P<0.05) estrus response with an increasing tendency in ovulation (84.6%) and pregnancy rates (30.8%) than PmPG, PGPE and P4PmPG treated buffaloes. Buffaloes treated with a dose of 0.4 (mg/kg) mifepristone, exhibited higher (P<0.05) estrous response (82.4%), ovulation (94.1%), and pregnancy (47.1%) rates compared with other dose (0, 0.3 or 0.5mg/kg) groups. Injection of mifepristone along second GnRH injection in buffaloes improved (P<0.05) pregnancy rate (35.3%) when compared to before or after 2nd GnRH of GPG protocol. Single AI after 24h of mifepristone or 2nd GnRH injection seems a best time to enhance the pregnancy rates in buffaloes compared to double or other single AI times. In comparison, GPGMH reduced the follicular cyst incidence (P<0.05), increasing ovulation (P>0.05) and pregnancy rates (P>0.05) than the P4GPG and GPG protocols in crossbred buffaloes. The current study supported that new synchronization protocol (modified of GPG protocol; GPGMH) by inclusion of mifepristone (with a dose of 0.4mg/kg along 2nd GnRH), AI after 24 h of mifepristone or 2nd GnRH and human chorionic gonadotropin (hCG at day 5 of AI) enhance the ovulation and pregnancy rates in crossbred buffaloes.