However, some species are induced ovulators, with ovulation occurring only following the stimulus of mating. Included in this group are the rabbit, cat, and mink. It has been established that ovulation in these species is the result of LH secretion in response to nerve impulses resulting from the mating act. Thus, both hormonal and nerve pathways are important factors in the reproductive process. There are wide differences between the species of mammals in the various characteristics of the estrous cycle.
Some species have only one heat period each year and are called monoestrous.
The cow is in a group that exhibits heat more than one time per year and is called polyestrous. The nonbreeding period is called anestrus. Therefore, cows should be fed on a high level of nutrition for rapid breeding. Estrus is not always accompanied by ovulation, nor ovulation by estrus. Such females will not accept service.