Foreword

Assisted reproduction techniques (ART) were slow to progress and be adopted after the establishment of embryo transfer in the horse. However, in the last two decades available techniques, clinical applications, and general acceptance within the equine industry have expanded rapidly. This has resulted in a cascade of new interest and firmly established their clinical relevance and applicability.

The horse presents some special challenges to and opportunities in ART. Horses are typically bred for performance, work, or show purposes, without special consideration to fertility or production capabilities. Their show or performance careers can delay use for reproductive purposes past the time of optimal fertility. In addition, scheduling, stress, and other factors associated with athletic activities can make reproduction more difficult.

The failure to establish repeatable methods for standard in vitro fertilisation in the horse resulted in the development and use of intracytoplasmic sperm injection (ICSI) for assisted fertilisation. The establishment of ICSI has provided a significant stimulus to research into physiology and developmental competence of the equine oocyte and early embryo, which was lagging behind many other species. In addition, ICSI allowed the expansion of clinical procedures, which have subsequently been widely accepted in many branches of the equine industry. Among these are methods to reliably collect and ship equine oocytes, allowing for the collection of oocytes by veterinarians in dispersed satellite practices, with overnight transport of gametes to central ICSI facilities. The ability to transport gametes and embryos and avoid moving horses provides more commercially feasible conditions. As in many areas of veterinary practice, the interaction of translational research and clinical advancement has been critical to progress in equine ART.

This special issue of Reproduction, Fertility and Development is a compilation of international research and clinical advancements in equine ART. It includes papers detailing the incorporation of ART into the equine breeding industry, current research into gamete and early embryo quality and physiology, and status of clinical procedures and related outcomes.

Elaine M. Carnevale, Lisa S. Metcalf, Tom A. E. Stout, Stuart Meyers and Zamira Gibb