Superovulation, embryo recovery, and pregnancy in seasonally anovulatory mares treated with recombinant equine FSH

PABLO J. ROSS MARIA V. ETCHARREN2, MARCELO H. MIRAGAYA3, ADRIAN MUTTO, MARK COLGIN5, JANET F. ROSER1, LUIS LOSINNO

JOURNAL OF EQUINE VETERINARY SCIENCE

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2012 vol. 32 p. 380 - 382

0737-0806

We evaluated the effectiveness of different treatments with recombinant equine FSH (reFSH) to stimulate follicular growth, multiple ovulations and embryo production in seasonally anovulatory mares. During winter (July-August in Argentina, South America) forty light breed donor mares, selected based on their reproductive records to have no more than 20% multiple ovulations per season, and presenting follicles 35 mm). More mares in groups 1 and 2 ovulated compared to group 3. Among ovulating mares, no differences in number of ovulations, number of embryos recovered, or pregnancy rates were observed among reFSH treatments. Overall, a 59% pregnancy rate was achieved with embryos collected and transferred during the anestrus season. These results indicate that treatment with reFSH during deep anestrus results in follicular development, ovulation of fertile oocytes, and production of viable embryos. Also a daily dose of 1.3 mg of reFSH, administered either as one or two daily injections, was more effective than a daily dose of 0.65 mg. In conclusion, reFSH treatment of seasonally anovulatory mares allows production of viable embryos during the winter season.