The Male Effect and Pheromones in Bovines: Neuroendocrine Mechanisms and Strategic Applications for Cattle and Buffalo Production

Livestock reproductive efficiency is a cornerstone of global food security; however, conditions such as postpartum anestrus and silent ovulation remain significant challenges in cattle and buffalo production. Although conventional hormonal interventions are effective, increasing demand for “clean, green, and ethical” production has shifted the focus toward biostimulation as a non-invasive alternative, particularly through the male effect. This review provides a comprehensive analysis of male-specific pheromones in bovines, specifically cattle (Bos taurus and Bos indicus) and buffalo (Bubalus bubalis). The neuroendocrine pathways through which male-derived volatile compounds activate the hypothalamic–pituitary–gonadal axis are discussed, with emphasis on the primary role of the vomeronasal organ in bovine species. Pheromonal signals are shown to target KNDy neurons (kisspeptin, neurokinin B, and dynorphin neurons) in the arcuate nucleus, thereby resetting the gonadotropin-releasing hormone pulse generator and inducing ovulation. Furthermore, physiological and metabolic constraints, such as negative energy balance and heat stress, are evaluated for their effects on increasing the activation threshold of the KNDy network and limiting the efficacy of biostimulation. By integrating management strategies such as optimizing bull-to-cow ratios and ensuring environmental and social well-being of females, the strategic potential of pheromonal tools for managing reproductive disorders is highlighted. Overall, establishing a comprehensive management framework that balances biostimulatory cues with metabolic and environmental optimization offers a scientifically grounded and sustainable pathway for enhancing reproductive productivity in cattle and buffalo production systems.