9 In vitro production of Charolais cattle embryos in the south-central Amazonian region of Ecuador
D. E. Argudo A B , J. C. Durán B , C. A. Soria B , H. Hernández-Fonseca C and F. P. Perea DA Unidad Académica de Ciencias Agropecuarias, Carrera de Medicina Veterinaria, Universidad Católica de Cuenca, Cuenca, Ecuador
B Singamia Cia. Ltda., Cuenca, Ecuador
C Department of Anatomy, Physiology and Pharmacology, School of Veterinary Medicine, St. George’s University, St. George’s, Grenada, West Indies
D Laboratorio de Biotecnología de la Reproducción Animal, Facultad de Ciencias Agropecuarias, Universidad de Cuenca, Cuenca, Ecuador
Reproduction, Fertility and Development 35(2) 129-129 https://doi.org/10.1071/RDv35n2Ab9
Published: 5 December 2022
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the IETS
Charolais cattle are widely utilised in the south-central region of the Ecuadorian Amazon. For several years, superovulation and embryo-transfer programs have been used for herd genetic improvement in this region. However, in 2021, a commercial program of in vitro embryo production (IVP) was initiated on several cattle farms. This study aimed to evaluate the results of the in vitro embryo-production program in Charolais donors in the Ecuadorian Amazon. Ovum pickup (OPU) and IVP were performed by commercial laboratory Singamia Cia. Ltda. between June 2021 and June 2022 on three farms. 26 different donors (multiparous open cows) were aspirated from June to September (dry season; n = 11) and October to May (rainy season; n = 15). In both seasons, body condition score ranged between 6 and 7 (1–9 scale). OPU was performed on a random day of the oestrous cycle, and the recovered cumulus-oocyte complexes (COCs) were transported to the laboratory in maturation medium (TCM-199 supplemented with 10 ng/mL EGF, 10% fetal bovine serum, 100 UI/mL FSHp, 1 µg/mL oestradiol, 100 µM cysteamine, 50 µg/mL gentamicin and HEPES). In vitro maturation was followed by in vitro fertilisation (Fert-TALP medium with heparin and PHE solution) and in vitro culture (SOFaaci) for 6 days. Proportions were analysed by chi-squared test, and blastocyst per OPU by GLM and Tukey test (SAS). Of 455 COCs recovered from the 26 donors, 314 (69%) were collected in the rainy season and 141 (31%) in the dry season. Table 1 shows the proportions of viable oocytes, cleavage rate, percentage of total embryos and grade 1 blastocysts, and the number of grade 1 blastocysts per donor. The proportion of viable oocytes (P = 0.0582) and the number of grade 1 blastocysts (P < 0.05) were greater in the rainy than in the dry season. However, the cleavage rate and proportion of total embryos and blastocysts were greater in the dry than in the rainy season. Because this is a preliminary report with a relatively small sample size, it is necessary to confirm our results in further studies. In conclusion, the collection of 2.6 more oocytes of good quality in the rainy season than in the dry season resulted in a greater production of Grade 1 blastocysts per Charolais donor cow in the south-central region of the Ecuadorian Amazon.
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