The stimuli which are most potent in eliciting a stress response to handling are often part of the management procedure itself (eg wool removal during shearing). If sheep handling is to be made less stressful, then alternative methods may have to be found which do not interfere with the procedure. Such alternatives may involve altering either the context in which sheep undergo handling procedures, or their experience of handling. This study tested whether repetition could modify the physiological response of sheep to handling.

Twenty three-year-old Merino wethers were sham shorn four times at intervals of two weeks. Sham shearing involves the noise and physical manipulations of shearing, but no wool is removed, allowing the procedure to be repeated. Two blood samples were collected via jugular catheters before sham shearing and eight were taken over the following eighty minutes. There were significant increases in haematocrit and plasma Cortisol after each exposure (p < 0.05). The Cortisol response to sham shearing was reduced by the previous experiences of the procedure (p < 0.05). This was manifested more in a diminution of the basal concentrations (23.34 ± 5.26 ng/ ml to 9.84 ± 5.50 ng/ml; n = 19) rather than a decline of the peak response (63.29 ± 5.50 ng/ml to 56.54 ± 7.25 ng/ml). There was no difference between the first and fourth exposures in the overall haematocrit response or in maximum haematocrit (33.3 ± 0.7% and 31.34 ± 0.9%; n = 17), however basal haematocrit was lower (p < 0.05) after the fourth exposure than it was after the first (23.6 ± 0.6% and 26.22 ± 0.8%) respectively.