Validation of an automated chemiluminescent immunoassay for salivary cortisol measurements in pigs

The aim of the current study was to validate an automated immunoassay for cortisol quantification in the saliva of pigs. The assay had intra- and interassay coefficients of variation lower than 16%, in all cases. The limit of detection was 0.016 µg/dl, and the lower quantification limit was 0.197 µg/dl. The assay also demonstrated a high level of accuracy, as determined by linearity under dilution and recovery tests. In addition, this assay was used to quantify cortisol in 2 models of stress: 1 in which animals were immobilized with a nose-snare and 1 in which pigs were transported for a duration of 30 min. In both cases, a significant increase (P < 0.01) in salivary cortisol was detected after the stressful situation. Overall, the assay validated in the present study could be used for the evaluation of cortisol changes in stressful situations.