Review of Techniques for Prediction of Ovulation in the Mare

1. Introduction
A decision on when to breed a mare by live cover or artificial insemination is usually dependent on an accurate prediction of impending ovulation. Prediction of the potential interval to ovulation is accomplished in clinical practice by interpretation and integration of multiple factors on an individual mare (Table 1). The goal of this paper is to review the parameters that can be used in clinical practice to predict impending ovulation in the mare.

2. Reproductive History
An individual mare will often ovulate a follicle of approximately the same diameter each cycle.¹ Consequently data from previous cycles can often be used to predict follicle size at ovulation of subsequent cycles. Unfortunately, some mares will ovulate a dominant follicle during one estrous cycle that is of a very different size, either markedly smaller or larger, than follicles of other cycles. Prediction of ovulation is difficult in these mares and more than one breeding may be required so the cycle is not missed. [...]