DEVELOPING THE INTRACYTOPLASMIC SPERM INJECTION (ICSI) PROCEDURE FOR THE HORSE

M.J. SANSINENA, D. PACCAMONTI, C. COCHRAN, M. MEINTJES, B. REGGIO, R.S. DENNISTON, C. PINTO, B. EILTS AND R.A. GODKE

Havermeyer Foundation Monograph Series

R & W (Newmarket) Limited

Lugar: Suffolk, UK; Año: 2003 vol. 6 p. 51 - 54

1472-3158

The mare has presented a unique problem to those scientists involved in assisted reproductive technology research. Embryo transfer (ET) was the first realistic procedure available to farm animals that could help to enhance the reproductive potential of the female. With the standard ET procedure, donor females are exposed to gonadotropinstimulation to produce multiple ova for in vivo fertilisation. Embryo collection and transfer procedures are considered relatively simple in the mare, producing acceptable pregnancy rates with good quality recipient females. Unfortunately attempts to superovulate donor horses generally produce poor results, making equine ET less acceptable to the horse industry. This may be due to the unique anatomical structure of the equine ovary and/or other unknown factors. The advent of in vitro fertilisation (IVF) techniques offered new opportunities for researchers in animal reproductive management. This in vitro technique was successfully used to produce the first offspring in farm animals, a healthy bull calf, reported by Brackett et al. (1982). Oocyte collection from live donors and IVF procedures became commercially available to dairy and beef cattle producers in the USA in the early 1990s. With thousands of bovine offspring produced worldwide, IVF is now used routinely in commercial cattle embryo transplant units. IVF in the mare has not developed to the level for in-field use as expected. Although several offspring have been reported in France using IVF in the mare in the early 1990s, repeatable IVF protocols are currently not available. As oocyte maturation and in vitro sperm zona penetration are primary problems hindering IVF development in horses, other assisted reproductive technologies, such as intracytoplasmic sperm injection (ICSI) and nuclear transfer are now being investigated.