Objective – This study compared 2 types of recombinant follicle stimulating hormone (rFSH): diluted and diluted/dynamized, on in vitro development of ovine follicles.Methods – In experiment 1, ovarian fragments were cultured for 1 or 7 days in α-MEM+ in the absence or presence of different concentrations of diluted rFSH to determine the best concentration. In experiment 2, the effect of diluted and diluted/dynamized rFSH (rFSH 6 cH—ultradiluted and succussioned), alone or in combination, was studied.Results – In experiment 1, compared to control, 50 ng/mL of diluted rFSH induced higher rates of follicular survival after 7 days of culture and higher percentages of growing follicles at day 1 of culture (P < 0.05). In experiment 2, compared to control, diluted/dynamized rFSH induced higher follicular diameter and survival rate after 7 days and early follicle activation at day 1 of culture (P < 0.05). Compared to diluted rFSH, diluted/dynamized rFSH induced higher rates of follicle activation at day 1 of culture (P < 0.05).Conclusion – In conclusion, compared to the control medium, diluted/dynamized rFSH promoted survival and early activation of follicles, while diluted rFSH promoted higher activation later in the culture. Thus, diluted/dynamized rFSH may be used as an alternative to diluted rFSH for the in vitro culture of ovine preantral follicles.