[Ovarian imbalance in swine].

The need for slaughtering sows is frequently related to fertility problems. These disturbances may be caused by uterine malfunction but for most instances they are the result of aberrations of ovarian function. Ovarian physiology of the sow highly depends upon rather complex events of both endocrinological and neuroendocrinological nature; disturbances of which may lead to either a stop of already started physiological patterns or even to a complete aberration. Atretic follicles, aberration of follicle maturing, ovarian cysts and low ovulation rates are common findings. Especially ovarian cysts have been seen on a high incidence in older sows. Results of recent research programs about the etiology of ovarian cysts are discussed.