RT Journal Article T1 Addressing Combative Behaviour in Spanish Bulls by Measuring Hormonal Indicators A1 Illera Del Portal, Juan Carlos A1 Jiménez Blanco, Francisco Javier A1 Centenera Rozas, Luis Alberto A1 Gil Cabrera, Fernando A1 Crespo, Belén A1 López, Paula Rocío A1 Silván Granado, Gema A1 Cáceres Ramos, Sara Cristina AB The fighting bull is characterised by its natural aggressiveness, but the physiological mechanisms that underlie its aggressive behaviour are poorly studied. This study determines the hormonal component of aggressiveness in fighting bulls by analysing their behaviour during a fight and correlating it to their serotonin, dopamine and testosterone levels. We also determine whether aggressive behaviour can be estimated in calves. Using 195 animals, samples were obtained when the animals were calves and after 5 years. Aggressiveness scores were obtained by an observational method during bullfights, and serotonin, dopamine and testosterone levels were determined in all animals using validated enzyme immunoassay kits. The results revealed a strong correlation of serotonin and dopamine levels with aggressiveness scores in bulls during fights, but no correlation was found with respect to testosterone. These correlations led to established cut-off point and linear regression curves to obtain expected aggressiveness scores for calves at shoeing. There were no significant differences between the expected scores obtained in calves and the observed scores in bulls. Therefore, this study demonstrates that hormone determination in calves may be a great indicator of combativeness in bulls and can reliably be used in the selection of fighting bulls. AB Simple Summary: Aggressiveness in fighting bulls is a natural characteristic of this breed, but little is known regarding it physiological mechanisms. Hormones such as serotonin, dopamine and testosterone are known to be involved in the development of aggressive behaviour. This study determines that serotonin and dopamine levels are correlated with combative behaviour, and its determination in calves is a useful indicator for the selection of combative bulls. PB MDPI YR 2024 FD 2024-04-22 LK https://hdl.handle.net/20.500.14352/104185 UL https://hdl.handle.net/20.500.14352/104185 LA eng NO Illera, J.C.; Jimenez-Blanco, F.; Centenera, L.; Gil-Cabrera, F.; Crespo, B.; Lopez, P.R.; Silvan, G.; Caceres, S. Addressing Combative Behaviour in Spanish Bulls by Measuring Hormonal Indicators. Vet. Sci. 2024, 11, 182. https://doi.org/ 10.3390/vetsci11040182 NO 2022 Descuento MDPI DS Docta Complutense RD 30 jun 2024