Niezgoda, J., Wro?ska, D., Pierzchala, K., Bobek, S. and Kahl, S. 1987. Lack of Adaptation to Repeated Emotional Stress Evoked by Isolation of Sheep from the Flock. Journal of Veterinary Medicine Series A. 34:734?739.

The aim of this study was to examine whether sheep can adapt to emotional stress evoked by individual isolation from the flock. The experiments were performed on 12 sheep divided into 2 groups; the control (kept in the sheepfold) and the experimental group in which sheep were isolated 3 times for 5 h at 3-day intervals. The plasma concentration of Cortisol and glucose served as indicators of stress. It was found that during 3 consecutive isolations the Cortisol level rose on average 3-fold above the initial value during the first to third hours of isolation. The calculated mean integrated response (? Cortisol) showed a gradual increase in its level in 3 consecutive isolations (122.3 30.6, 189.4 18.9 and 277.9 39.2 nmol/1/5 h). The concentration of glucose increased at 3 and 5 h after starting the experiment on average by 1.0 to 1.8 mmol/l. However, the mean integrated response of glucose was almost the same in all 3 isolations. The results show that in sheep no adaptation occurred to repeated isolation stress and, in contrast to glucose level, the plasma Cortisol concentration seems to be a valuable index of adaptation to emotional stress.