Behavior Patterns of Colombian Creole Bulls Romosinuano and Costeño Con Cuernos

The objective of this study was to characterize the sexual behavior and reproductive performance of Colombian Creole bulls from the Romosinuano (ROM) and Costeño con Cuernos (CCC) breeds, to support their strategic use in tropical production systems and sire selection programs. A standardized sexual behavior test, including nine behavioral indicators, was conducted over a 15 min observation period to assess libido and service capacity. Significant differences (p < 0.05) were found between the breeds in terms of the frequency of urination and mounting behaviors. ROM bulls exhibited a more uniform and rapid behavioral response, while CCC bulls showed greater individual variability and a broader behavioral repertoire, with courtship behaviors—such as smelling, the Flehmen reflex, and butting—strongly associated with ejaculation events. Libido scores were high in both breeds, with 80.35% of bulls rated as very good to excellent. CCC bulls also achieved mounts more frequently within the first five minutes of exposure. Additionally, bull age was inversely associated with mounting time (p < 0.05), suggesting that maturity and sexual experience influence behavioral efficiency. These findings represent the first quantitative assessment of sexual behavior in CCC bulls and provide comparative insights with ROM bulls, highlighting the functional reproductive potential of Colombian Creole bulls under low-input tropical conditions.