When I was little, I worked in the stable and I saw a bull approach a cow that was urinating and stick its nose right in the urine. Then I'd think 'what the hell are you doing, you know it's not water, right?'. I could never understand why the bull would do such a thing. Well, now I know… he was smelling her pheromones. “Pheromones are airborne chemical signals that are released during urination or in animal feces (Rekwot).” Pheromones are secreted by skin glands; from there they are then perceived by the olfactory system where they stimulate a behavioral or endocrine response. In response to the signals released, the reaction that occurs in the animal's body involves the reaction of a specific behavior or a change in the endocrine or reproductive system. There are two types of pheromones: signaling pheromones and priming pheromones (Rekwot). Signaling pheromones cause an immediate behavioral response, invoking a stimulus or the transfer of information between animals. The area affected by pheromone signaling is the olfactory signal. Olfactory signals convey specific information and this translates into a specific and immediate behavioral response in the male. The olfactory signal can also be produced in the urine or vaginal secretions of females (Rekwot). Males investigate the anogenital regions of females, this includes sniffing, licking and nuzzling that area, this will induce urination from the female. The male will then put his snout and mouth directly into the urine; this is related to the vomeronasal organ (VNO). VNO neurons then respond to pheromones. Another function of the VNO is believed to be to stimulate and maintain sexual activity through olfactory stimuli (Stowers 699-7032). P...... middle of paper ..... Flows respond to pheromone stimulation from bulls in a dose-dependent manner. “Cows that did not perceive the minimum daily dose or threshold of pheromone stimulation and relaxation cycles did not receive the appropriate biostimulatory signal and did not resume OA. (Taurck 13-18)Many mammals use chemosignals to synchronize reproduction by altering their physiology and behavior. In case of reproductive problems, the odors produced and deposited by both males and females are used to find and select an individual for mating. The production, dissemination, and appropriate responses to these signals are modulated by the organizational and activating effects of gonadal sex steroids. Thus intrinsically linking chemical communication to the broader reproductive context. Pheromones are becoming a very popular topic; however, there is a lot missing in the research and information part.