The ram effect is a well-known phenomenon in sheep, whereby the introduction of a sexually active ram in a group of anoestrous ewes induces luteinizing hormone (LH) secretion and ovulation. Previous studies verified the implication of the chemical communication in this phenomenon, also describing the role of the ram anteorbital gland secretion in this effect induction. However, the olfactory pathways involved in the treatment of these cues haven’t been fully investigated. This study aimed to use the anti-c-Fos immunohistochemistry (IHC) to evaluate if the main and accessory olfactory bulb (MOB and AOB) are differentially activated by the anteorbital gland secretion of subjects having a different sexual status. Sixteen anoestrous ewes were divided into 4 groups to test the anteorbital gland secretions from entire rams, neutered males, and females. The fourth was the control group. After 20 minutes of inhalation, ewes were humanely euthanized and the brains submitted to IHC. The number of c-Fos+ neurons was counted in 1 mm2 in the MOB and AOB of each ewe, and the Kruskal-Wallis one-way ANOVA and the Wilcoxon two-sample test were used. The MOB was activated without statistical difference by the neutered and entire male secretion (170±4 vs 201±23 cells/1mm2, p>0.05). Male secretions activated the MOB more than females (140±5, p<0.05). The AOB was significantly more activated by the entire ram secretion (113±5, p>0.05) than other treatments, which showed a statistical difference in this order: neutered (89±2), females (58±2) and control group (15±2). Our data suggest that the MOB recognizes male secretion without distinguishing between entire and neutered males. This distinction is then done by the AOB. In conclusion, the main olfactory system seems necessary to identify the presence of a male, probably inducing sheep vomeronasal organ opening, entire male pheromones detection and AOB activation, triggering then the brain circuit leading to LH peaks and ovulation.