The development and application of the modern reproductive technologies to horse breeding.

This research article explores the advancements in reproductive technologies related to horse breeding. The advancements include improvements in extenders and cryoprotectants, ovulation induction and synchrony, exogenous gonadotrophic stimulation methods, and non-surgical transfer of embryos. These developments have led to an increased usage of embryo transfer in horse breeding worldwide, with notable exceptions. The article also discusses the potential of technologies like cloning in the breeding of sport horses.

Development and Use of Modern Breeding Technologies

• The research begins by comparing the rate of adoption of modern breeding technologies in horse breeding to other large domestic species. While horses were one of the first animals to benefit from artificial insemination, the adoption of newer techniques such as embryo transfer was slower. However, in recent years, horses are catching up quickly.
• The paper outlines the increase in the use of extenders and cryoprotectants in the transportation and insemination of cooled and frozen stallion semen. These improvements have significantly contributed to the recent surge in the application of these technologies in horse breeding.

Improvements in Ovulation Induction and Embryo Transfer

• The article also discusses advancements in ovulation induction and synchrony. These improvements, along with the application of exogenous gonadotrophic stimulation, have facilitated multiple fertile ovulations in mares.
• More efficient methods for non-surgical transfer of embryos to recipient mares have been developed. This, along with relaxed breed society registration restrictions, has contributed to a worldwide increase in the use of embryo transfer for all breeds and athletic types of horses. The only exception mentioned is the Thoroughbred.

Innovative Breeding Technologies

• Despite conventional in vitro fertilization remaining a challenge in equids, other modern breeding technologies have recorded encouraging success. These technologies include hysteroscopic low-dose insemination, fluorescence-activated sex sorting of stallion spermatozoa, between-species embryo transfer, embryo freezing and bisection, and transvaginal ultrasound-guided oocyte collection.
• The research highlights the successful application of Intracytoplasmic Sperm Injection (ICSI), Gamete Intrafallopian Transfer (GIFT), and nuclear transfer (cloning) in horse breeding.
• Particularly, cloning is seen as a promising technology for the sport horse industry, offering the potential to recreate champion geldings in stallion form for breeding purposes.