Basal Salivary Cortisol Levels Research Articles

A fast and simple technique for jugular catheterization in adult sows.

Obtaining measures of an animal's physiological state with minimum disturbance to the animal is essential in animal welfare studies and it is also ethically desirable. A simple technique for implanting a temporary jugular catheter in adult sows is described. The technique involves implantation via an ear vein and can be performed in 5-7 min. Local but not general anaesthetic is required. The technique has no effect on basal levels of salivary cortisol 1-2 h later, suggesting that it has no long term stress consequences. Catheters continue to function perfectly well after 4 h.

Salivary cortisol in pigs following adrenocorticotrophic hormone stimulation: Comparison with plasma levels

Four prepubertal pigs were prepared with venous catheters and housed in metabolism cages. Plasma and saliva samples were taken at 15-min intervals over a 105-min period and analysed by radioimmunoassay for total (i.e. free and bound) cortisol content. Adrenocorticotrophic hormone (ACTH) was given i.v. at three different doses (0·5, 1·0 and 2·0 mg) after the second sample and the cortisol responses were compared with pretreatment values and levels observed after saline vehicle administration. Basal levels of salivary cortisol were approximately 10% of those in plasma. ACTH induced significant increases in plasma and salivary cortisol but in no case was a dose/response relationship detected. Plasma cortisol showed a maximum increase of approximately 230% whereas salivary cortisol increased only by about 130%, indicating that salivary cortisol is a less sensitive indicator of adrenal activity than plasma cortisol in this species. Estimation of salivary cortisol concentrations may offer practical advantages for the assessment of stress responses in intensively housed pigs.