**Abstract**

Chemical signals that mediate communication within animals of a species have been referred to as 'pheromone' a Greek word comprised of 'pheran' (means to transfer) and 'hormon' (to excite). These chemical messengers are transported outside the body and have a direct developmental effect on hormone levels and behavior, and therefore, have a potential role in modulating animal behavior and reproductive management. The sources of these chemical messengers are urine, vaginal secretions, feces, saliva, milk, sweat, breath and specialized cutaneous glands including the odor produced from hair and wool. After their release, are perceived through the olfactory system, eliciting both behavioral and endocrine responses characterized by profound effects on reproductive activity via the hypothalamic system that generates pulses of gonadotropin-releasing hormone. Their potential to transform the animal behavior and reproduction management has led to development and use of synthetic pheromones to manipulate estrous cycle, enhance estrous behavior, determination of time of estrus, and also facilitating collection of semen. Pheromones can act as a marker to detect estrus, diagnosing early pregnancy in farm animals and used for improving sexual desire. There is huge scope of application of pheromones once chemically synthesized and characterized, and would be of great interest to livestock owners and consumers. This chapter will discuss in detail the role of chemical signaling in shaping the behavior, reproduction and understanding the ways of communication in bovines.

**Keywords:** chemical signaling, pheromone, animal behavior and reproduction
