Investigation of Reproductive Traits and a Computer-Assisted Single Artificial Insemination Procedure in Mares in Subtropical Taiwan

Abstract

The objective of this study was to report the reproductive traits of mares by ultrasonography and hormone analyses in subtropical Taiwan and the successful artificial breeding of mares using a self-developed computer-assisted single insemination technique. A previously developed computer-assisted image analysis technique at our reproduction centre was employed to determine the optimal time for artificial insemination (AI). In the 8 mares that underwent this AI procedure, ovulations all occurred within 12 h post-insemination and 5 mares were impregnated (62.5%). The combined results of ultrasonic examination and hormone analyses showed that the mares in Taiwan were not only possible defined seasonal breeders, but also polyoestrous breeders that could be bred throughout the year. It is suggested that mares could be injected with only 1 dose of 500 x 10(6) total spermatozoa into the uterine body at the time determined by this developed programme to obtain a satisfactory pregnancy rate.