195 Follicular wave synchronisation with oestradiol Benzoate or gonadotrophin-releasing hormone for ovum pickup in lactating Holstein cows
D. F. Idrovo A , J. C. Alvarado A , A. L. Moscoso A , C. A. Soria B , J. C. Durán B and D. E. Argudo A BA Unidad Académica de Ciencias Agropecuarias, Carrera de Medicina Veterinaria, Universidad Católica de Cuenca, Cuenca, Ecuador
B Singamia Cia. Ltda., Cuenca, Ecuador
Reproduction, Fertility and Development 35(2) 225-226 https://doi.org/10.1071/RDv35n2Ab195
Published: 5 December 2022
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the IETS
Several strategies have been tested to improve in vitro embryo production efficiency in cattle. A successful strategy has been the synchronisation of the follicular wave with protocols based on progesterone and oestradiol benzoate (EB); however, EB is banned in several countries and will soon be banned in others. This study aimed to compare the use of gonadotrophin-releasing hormone (GnRH) and EB in the synchronisation of the follicular wave before OPU. A total of 12 lactating Holstein cows aged 3–8 years were divided into two treatments in a 2 × 2 crossover design in four replicates. On Day 0, cows received a P4 implant of 0.6 g (Disprogest, Zoovet®) and 150 µg of D-cloprostenol (Dextrogenol, Von Franken®), then were randomly divided into two groups; the BE group received 2 mg of Oestradiol benzoate (Von Franken®) and the GnRH group received 10.5 µg of Buserelina acetate (Gestar, Over®). On Day 5, the P4 implant was removed and OPU was performed. Table 1 shows the size and number of the antral follicles, presence of corpus luteum (CL) follicles > 10 mm, as well as the number of recovered and viable oocytes. In addition, a proportion of viable oocytes was used to determine their integrity with the use of Trypan blue, while another group was subjected to Brilliant Cresyl Blue (BCB) staining to establish their competence. The rest of the viable oocytes were subjected to IVF with sexed semen and, on Day 7, post-IVF embryo production was recorded. ANOVA was performed to compare the averages and chi-squared for the frequencies and statistical difference at P < 0.05 was considered significant. All analyses were performed with the statistical software SPSS statistics version 23. There were no differences between groups; however, in the GnRH group, there was a tendency (P < 0.10) for the antral follicles to be larger, the viable oocytes to be more competent, and a greater presence of CL at OPU. In conclusion, synchronising the follicular wave before OPU with GnRH or EB in lactating Holstein cows produces the same number of viable oocytes and embryos.
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