Conception rate after fixed time insemination following ovsynch protocol with and without progesterone supplementation in cyclic and non-cyclic Mediterranean Italian buffaloes (Bubalus bubalis).
The aim of this study was to test the effect of progesterone supplementation to Ovsynch protocol in cyclic and non-cyclic Mediterranean Italian buffaloes on conception rate after fixed time artificial insemination. From 169 pluriparous buffaloes, 2 groups were identified and subjected to: (1) Ovsynch protocol (OV; n=83) and (2) Ovsynch protocol with the supplementation of progesterone from days 0 to 7 (OV+PROG.; n=86). All cows were inseminated 16-20 h after the second GnRH administration. Within each group, non-cyclic buffaloes were identified (OV=21 and OV+PROG.=20). Overall conception rate was significantly higher in cyclic compared to non-cyclic buffaloes: 43.7% versus 17.0%, respectively, P=0.001. A significant effect of progesterone supplementation on conception rate was observed in non-cyclic buffaloes (30% versus 4.7%, P=0.04) but not in cyclic buffaloes (51.5% versus 35.7%, P=0.077). Collectively, the presence of a large follicle (>or=10 mm) detected at the beginning of the Ovsynch protocol by ultrasound significantly affected conception rate (44% versus 8%, P=0.01). The findings of the present study suggest that (i) progesterone supplementation to the Ovsynch protocol in buffaloes increases conception rate in non-cyclic animals, (ii) the presence of a large follicle at the beginning of the Ovsynch protocol is a determining factor for a successful synchronization of ovulation and high conception rates and (iii) ultrasound monitoring can improve the overall efficiency by selectively identifying more suitable cycling animals carrying a responsive follicle at the time of first GnRH administration.
De Rensis
F
F
Dipartimento di Salute Animale, Facoltà di Medicina Veterinaria, Parma, Italy. fabio.derensis@unipr.it
Ronci
G
G
Guarneri
P
P
Nguyen
Bui Xuan
BX
Presicce
G A
GA
Huszenicza
G
G
Scaramuzzi
R J
RJ
D000818:Animals; D002020:Buffaloes / Q000502:physiology*; D030762:Estrous Cycle / Q000502:physiology*; D004973:Estrus Synchronization / Q000379:methods*; D005260:Female; D005306:Fertilization / Q000502:physiology; D007315:Insemination, Artificial / Q000662:veterinary; D008297:Male; D010062:Ovulation Induction / Q000379:methods / Q000662:veterinary*; D011374:Progesterone / Q000008:administration & dosage / Q000494:pharmacology*; D011897:Random Allocation
D011374:Progesterone