We hypothesized that challenging mainly prepubertal but also a certain number of adult gilts with exogenous gonadotropins (eCG/hCG) after altrenogest priming could disturb the development of some preovulatory follicles, which would not ovulate after hCG administration (or after the native LH preovulatory surge onset) and would become ovarian cysts. Here, PLOD1 is linked to Ovarian cyst.