Pre-synchronization protocol in crossbred cows in the postpartun period
ABSTRACT. Almeida I.C., Sobreira R.R., Oliveira F.A., Garcia Y.L., Madureira A.P., Barioni G. & Siqueira J.B. [Pre-synchronization protocol in crossbred cows in the postpartun period.] Protocolo de pré-sincronização hormonal em vacas mestiças no período pós-parto. Revista Brasileira de Medicina Veterinária, 38(4):353-357, 2016. Departamento de Medicina Veterinária, Universidade Federal do Espírito Santo, Alto Universitário s/n, Caixa Postal 16, Alegre, ES 29500-000, Brasil. E-mail: firstname.lastname@example.org
Evaluate the efficiency of the pre-synchronization hormonal in crossbred cows in early postpartum regarding the follicular dynamics and reproductive efficiency. In the control group (CG; n=45) animals were subjected to time-fixed artificial insemination protocol (TAI), composed of progesterone, estradiol, prostaglandin and equine chorionic gonadotropin. In the treatment group (TG; n=47) animals were subjected to hormonal pre-synchronization protocol for the progesterone (reused implant for 24 days) and estradiol, before the TAI, the TAI protocol being identical to CG. No difference (P˃0.05) in the number of follicles in the days between treatments evaluated. There was no effect (P˃0.05) treatment on the diameter of the follicle when TAI (TG = 12.5 ± 1.61mm and CG = 11.9 ± 2.26mm). No difference (P˃0.05) in the ovulation rate (TG = 88.8% and CG = 75%) and pregnancy rate (TG = 53.84% and CG = 38.46%). There were differences (P˂0.05) in pregnancy rate between primiparous cows (23.07%) and multiparous (69.23%) for the TG. The use of hormonal pre-synchronization protocol showed no marked differences in the evaluated patterns of follicular dynamics. Multiparous cows had higher pregnancy rate primiparous cows to the treatment group.