Evaluation of plasma cortisol and TBARS levels in calves after short - term transportation

The particular role of stress factors in pathology of bovine diseases has been observed. In many cases these factors have been estimated as main predisposing factors to infectious diseases [6]. Exposure to stress conditions (e.g. weaning, transport, remixing of animals, high temperature) has been associated with activation of the hypothalamic-pituitaryadrenal axis. The result of these processes is the stimulation of the steroid hormones secretion by adrenal cortex. The increased release of adrenocorticotropic hormone (ACTH), which leads to the elevation of glucocorticoid concentrations is thought to be the primary agent mediating negative effects of stress on the biochemical processes [28]. Therefore, glucocorticoids (especially cortisol) concentrations in blood and its metabolites in feaces (11.17 DOA 11.17 Dioxoandrostanes) are widely used as a measure of stress in cattle [4, 17, 18, 19].