Relationship between saliva and blood cortisol in handled cows

Objective The objective of the study was to determine the relationship between plasma and salivary cortisol concentrations in beef cattle that were subjected to handling prior to sampling. Methods Twenty-one Nguni cows of three age categories; 5 to 7 yr (n = 7), 8 to 10 yr (n = 6), and 11 to 13 yr (n = 8) were handled for five consecutive weeks. In the pen, a human avoidance test was performed and cattle responses to restraint in the chute and crush were observed. In addition, rectal temperature readings were taken and, faecal samples were collected and analysed for glucocorticoid metabolites. Through the handling and restraint process, excretory and vocalisation behaviour, as a sign of stress were observed and recorded. Thereafter, six cows were randomly selected and subjected to an adrenocorticotropic hormone (ACTH) challenge. Blood and saliva samples were extracted to determine cortisol concentrations. Results Repeated handling affected (p0.05) across the time of sampling. A low and insignificant correlation (r = 0.0131, p>0.05) between plasma and saliva cortisol was therefore observed. Conclusion We conclude that if beef cows are subjected to handling prior to sampling, a weak relationship exists between plasma and salivary cortisol levels