Abstract
The crossbreeding of Swamp and River type 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 the fixed-timed artificial insemination (FTAI) for better reproductive performance of crossbred buffaloes. Comparison of four conventional synchronization protocols [pregnant mare gonadotropin-prostaglandin F2α-gonadotropin-releasing hormone (PmPG), gonadotropin-releasing hormone-prostaglandin F2α-gonadotropin-releasing hormone (GPG), prostaglandin F2α-gonadotropin-releasing hormone-prostaglandin F2α-estradiol benzoate (PGPE), and progesterone-pregnant mare gonadotropin-prostaglandin F2α-gonadotropin-releasing hormone (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 combined with GPG, exhibited higher (P < 0.05) estrous response (82.4%), ovulation (94.1%), and pregnancy (47.1%) rates compared with other doses (0, 0.3, or 0.5 mg/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 the second GnRH of GPG protocol. Single AI after 24 h of mifepristone or second GnRH injection seems the best time to enhance the pregnancy rates in buffaloes compared to double or other single AI times in the modified GPGMH protocol. In comparison, GPGMH reduced the follicular cyst incidence (P < 0.05) with 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 the inclusion of mifepristone (with a dose of 0.4 mg/kg along second GnRH), AI after 24 h of mifepristone or second GnRH, and human chorionic gonadotropin (hCG at day 5 of AI) enhance the ovulation and pregnancy rates in crossbred buffaloes.
Highlights
The buffalo is the second largest species of dairy livestock in the world
Buffaloes treated with gonadotropin-releasing hormone (GPG) showed a higher estrus rate (96.1%; P < 0.05) with an increasing trend in ovulation (84.6%; P > 0.05), and pregnancy rate (30.8%; P > 0.05) with lower silent estrus (3.8%; P < 0.05) and follicular cyst (3.8%; P < 0.05) rates compared to pregnant mare gonadotropin-prostaglandin F2α-gonadotropin-releasing hormone (PmPG), prostaglandin F2α-gonadotropin-releasing hormone-prostaglandin F2α-estradiol benzoate (PGPE), and P4PmPG treated buffaloes
The diameter of the ovulatory follicle was similar in buffaloes treated with different protocols (GPG, PmPG, PGPE, and P4PmPG) (Table 1)
Summary
The buffalo is the second largest species of dairy livestock in the world. China has the third highest population of buffaloes in the world, following India and Pakistan. Crossbreeding of swamp (2n = 48) with river buffaloes (2n = 50) resulted in a hybrid progeny (49 chromosomes) [3] and crossbred progeny of buffaloes has relatively lower fertility than pure breeds. Compared with cattle, buffalo exhibit higher reproductive problems such as seasonal breeding, delayed puberty, longer post-partum intervals, and silent heat [4]. These factors make it difficult to apply synchronization protocols vigorously, as practiced in cows. In this scenario, the crossbred progeny of buffaloes needs greater attention for reproductive management
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
