HYPOTHALAMO-PITUITARY-ADRENAL AXIS ACTIVA TION AND ITS RELATIONSHIP WITH BEHAVIOR IN FIGHTING BULLS DURING THE BULLFIGHT

This work studies the effect of bullfight on the hypotalamo-pituitary- adrenal (HPA) axis in fighting bull using direct (serum cortisol and A CTH levels) and indirect (WBC, differential count of white cells, seru m glucose and adrenal cholesterol) markers for stress. In this respect , bulls bullfighted in two different festivals, San Fermin (Pamplona) and El Pilar (Zaragoza), were used. The presence of the ''encierro'' i n Pamplona was the only difference between both festivals. All animals used in the study showed stress, proved by the modification of the ma rkers quoted above. The number of animals having fallen in San Fermin was lower than that found in El Pilar. These differences could be due to the ''encierro'', that can be a stimulus that activates the HPA axi s before bullfight and induces a higher response to the stress of bull fight. Another interesting fact is the higher concentration of adrenal cholesterol in the bulls fighted in Pamplona, that could mean a bette r adrenal reserve and a higher capacity to response to stress.