Estrous Behavior in the Thoroughbred-Indonesian Local Crossbred Mares

Abstract

The development of horse breeding industry in Indonesia was commenced through horse racing events held all over the country. It were accelerated by the development of Thoroughbred-Indonesian local Crossbred horses. There are many broodmares injured during their racing time and retired from the racetracks. They may still has a reproductive vigor to continue on producing offsprings. A few information has been reported on the monitoring the reproductive capacity of the mares. The objective of this study was to explore the estrus behavior correlated with ultrasonography imaging of the ovarian dynamics of the Thoroughbred-Indonesian local crossbred mares. Three Thoroughbred-Indonesian local crossbred mares with 6.25-12.5% of local genetics aged 12-20 years old were used in this study. Ultrasonography examination was done every morning at approximately at the same time. Estrus behavior was observed by using teaser stallions following a standard method. Results of the experiment indicated that mares show estrous behavior such as winked vulva, squatting, receive the stallion, tail raised, urinating, and mating stand in the ovulation time that occured in the day 25.4±3.78 (estrous cycle) correlated with the diameter of domminant follicle 4.2±1.44 cm. In conclusion, Estrous behavior can be used to monitor the estrous cycle to optimized the mating time in the mares.