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

• Grant number: 16/12017-3
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: July 01, 2016
• End date: December 31, 2016
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Roberto Sartori Filho
• Grantee: Roberto Sartori Filho
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The objective was to evaluate in vitro embryo production (IVEP) in non-lactating Holstein cows after ovarian superstimulation. Cows were randomly assigned in a crossover design to one of two groups: Control (n = 35): not synchronized and not treated with hormones prior to OPU or Hormone-treated (n = 35): wave emergence synchronized and treated with p-FSH in the presence of norgestomet prior to OPU. In the Hormone-treated group, all follicles e 7 mm in diameter were aspirated for synchronization of wave emergence and cows received a norgestomet ear implant. After 36 h, treatment with p-FSH (six doses of 40 mg each, 12 h apart, i.m.) started. The OPU from follicles > 2 mm in diameter was performed 44 h after the last p-FSH (coasting). Then, IVEP was performed. The total number of cumulus-oocyte complexes (COC) 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, respectively. Additionally, there were no differences in the number of blastocysts per cow per OPU (3.0 vs 2.6 ± 0.5), or 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 non-lactating Holstein cows that had synchronization of wave emergence and progestin supplementation, did not improve oocyte quality or IVEP compared to no hormonal treatment. (AU)