The ovaries of the mare are usually the most anterior part
of the reproductive tract in the nonpregnant mare (see
Figure 1-3 ). The noncoiled and dorsally suspended uterus
of the mare (as compared with the coiled tract and more
posterior [fl ank] broad ligament attachment in other farm
animal species) accounts for the more cranial location
of the ovaries. So, in the mare, the ovaries are in the cranial-most transverse plane, whereas in other farm animal
species, a portion of the uterus is cranial to the ovaries.
The ovaries and the follicles are larger in the mare
than in other farm animal species (see Figure 2-5 ). Equine
ovaries are bean-shaped and vary in size according to
ovarian activity; they are largest during the breeding
season (spring and summer) and smallest during the
nonbreeding season (winter anestrus). Average ovaries
are 6 to 8 cm in length, 3 to 4 cm in height, and 70 to 80 g
in weight.