Short communication: Follicle superstimulation before ovum pick-up for in vitro embryo production in Holstein cows

Abstract

The objective was to evaluate in vitro embryo production (IVEP) in nonlactating Holstein cows after ovarian superstimulation. Cows were randomly assigned in a crossover design to 1 of 2 groups: control (n=35), which was not synchronized and not treated with hormones before ovum pick-up (OPU), or hormone-treated (n=35), in which wave emergence was synchronized and animals treated with porcine (p)-FSH in the presence of norgestomet before OPU. In the hormone-treated group, all follicles ≥7mm in diameter were aspirated for synchronization of wave emergence and cows received a norgestomet ear implant. After 36h, treatment with p-FSH (6 doses of 40mg each, 12h apart, i.m.) started. Ovum pick-up from follicles >2mm in diameter was performed 44h after the last p-FSH (coasting). Then, IVEP was performed. The total number of cumulus-oocyte complexes recovered (16.0 vs. 20.5±2.2) and number of grades I to III (viable) oocytes (10.7 vs. 12.3±1.6) did not differ between hormone-treated and control groups Additionally, no differences were found in the number of blastocysts per cow per OPU (3.0 vs. 2.6±0.5) or in blastocyst rates (17.1 vs. 12.2±2.4%) between hormone-treated and control, respectively. Thus, in this study, ovarian follicle superstimulation with p-FSH followed by coasting in nonlactating Holstein cows that had synchronization of wave emergence and progestin supplementation did not improve oocyte quality or IVEP compared to no hormonal treatment.

Equine chorionic gonadotropin drives the transcriptional profile of immature cumulus‐oocyte complexes and in vitro‐produced blastocysts of superstimulated Nelore cows

“…In the present study, we demonstrated the transcriptional differences generated by superstimulation using eCG combined with FSH on immature COCs and blastocysts from superstimulated Nelore cows. Although our results corroborated the findings of L. H. Oliveira et al () and showed that neither superstimulatory treatment affected blastocyst rates, we found several differences in COCs and blastocysts gene expression profiles between the superstimulatory treatments.…”

Strategies to increment in vivo and in vitro embryo production and transfer in cattle

“…Although administration of FSH prior to OPU has been a common practice for increasing the numbers of follicles available for OPU, most studies have adopted the conventional twice daily treatments with FSH, with either positive results in the number of COCs collected and embryos produced (Ongaratto et al, 2011;Blondin et al, 2012;Vieira et al, 2014; or no effect on COC or embryo production in Holstein cows (Oliveira et al, 2016). Obviously, the possibility of giving a single FSH injection instead of four prior to OPU in genetically superior animals is critically important for the widespread application of this technology in commercial herds, where personnel are not as familiar with intensive treatment protocols as producers working with purebred cattle.…”

Ovum Pick Up (Opu) by Transvaginal Ultrasonography in Cattle

“…Use of gonadotropin hormones before OPU, can increase the ratio of follicles with intermediate diameters (>6 and <10 mm) in the ovary (Goodhand et al 1999). Therefore, gonadotropin applications during follicular development can be used to achieve ideal follicles for IVEP (Oliveira et al 2016). Three different gonadotropins are used for ovarian superstimulation in cattle.…”