238 Superstimulation of Nelore prepubertal heifers using a long-acting recombinant human FSH: effects upon oocyte yield and in vitro embryo production
R. Moura A , L. Martins A , C. Fernandes B , L. Siqueira C , R. Figueiredo D , M. Peixer E , M. Xavier E and J. Viana A DA Universidade de Brasília, Brasília, DF, Brazil
B Universidade de Alfenas, Alfenas, MG, Brazil
C Embrapa Gado de Leite, Juiz de Fora, MG, Brazil
D Embrapa Recursos Genéticos e Biotecnologia, Brasília, DF, Brazil
E Bio Biotecnologia Animal, Brasilia, DF, Brazil
Reproduction, Fertility and Development 35(2) 248-248 https://doi.org/10.1071/RDv35n2Ab238
Published: 5 December 2022
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the IETS
The aim of this study was to evaluate oocyte yield and in vitro embryo production (IVEP) in prepubertal heifers submitted to ovarian superstimulation with a long-acting human recombinant FSH (rhFSH) followed by ovum pickup (OPU) and IVEP. Nelore heifers (n = 90) at ∼8 months were randomly allocated into 5 groups: (1) control (CG), no pre-stimulation; (2) 10 mcg rhFSH SC (Corifollitropin Alpha, Shering-Plough) and OPU 96 h later (FSH96); (3) 10 mcg rhFSH SC and OPU 120 h later (FSH120); (4) 200 IU equine chorionic gonadotrophin (eCG) IM (Sincro eCG, OuroFino) and OPU 96 h later (eCG96); (5) 200 IU eCG IM and OPU 120 h later (eCG120). Nelore mature cows (n = 10) were used as a reference for IVEP outcomes. Ovaries were considered as superstimulated if average follicle size at OPU was >7 mm. OPU and IVEP were performed by the same team of technicians, using standard commercial procedures. Data were analysed using the Glimmix or Npar procedures of SAS. Only heifers receiving rhFSH presented effective ovarian superstimulation (100% in FSH96 and 92.3% in FSH120 vs 13.3% in eCG96 and 0.0% in eCG120, respectively; P < 0.0001). Vaginal mucus discharge was more frequently observed for FSH120 heifers than for FSH96, eCG96, or eCG120 (69.2% vs 20.0%, 6.7%, and 20.0%, respectively; P < 0,0001). The use of rhFSH increased the proportion of Grade I COC compared with eCG or controls (37.6% and 24.8% for FSH96 and FSH120 vs 10.8%, 13.6%, and 14.1% for eCG96, eCG120, and CG, respectively; P < 0.0001). However, rhFSH also increased the proportion of expanded COC (10.2% and 22.3% for FSH 96 and FSH120 vs 1.7%, 1.7%, and 0.0% for eCG96, eCG120, and CG, respectively; P < 0.0001), resulting in a lower proportion of viable COC in rhFSH-treated groups (71.8% and 66.9% vs 88.0%, 88.6%, and 85.5%, respectively; P < 0.0001). Moreover, total COC were lesser for FSH120 compared with CG (9.3 ± 1.2b vs 21.6 ± 1.9; P = 0.0034), though similar (P > 0.05) to the other groups. Data on IVEP of FSH96 COCs was discarded due to contamination during IVEP. Blastocyst rate using mature cows COC was similar to FSH120 (54.5% vs 41.4%; P > 0.05), but greater than eCG96, eCG120, and CG (30.8%, 24.9%, and 35.4%, respectively; P < 0.0079). In summary, treatment with rhFSH was effective to promote superstimulation in prepubertal heifers with a single SC injection. However, the potential benefits of a long-stimulatory protocol using rhFSH have been overshadowed by a decrease in both total number and proportion of viable COC recovered.
This research was supported by CAPES, DPG UnB, and FAPDF.
