Some authors suggest that the presence of ovarian cysts is related to seasons of the year.
Liptrap and Doble (1981) suggesting that there is a greater incidence of cysts in spring than
in autumn. According to Gherpelli and Tarocco (1996), the incidence is greater in autumn
and winter months. The present trial was performed from autumn to spring and no seasonal
effect was found during this period. Another factor that should be taken into account is
the difference in temperatures and photoperiod due to location and time of the year in the
present trial. In spite of these facts, the presence of ovarian cysts in sows at both farms
was similar, thus suggesting that these factors were not significant in contributing to the
formation of ovarian cysts.