EFFECTS OF SHORT-TERM RESTRAINT STRESS ON PLASMA-CONCENTRATIONS OF CATECHOLAMINES, BETA-ENDORPHIN, AND CORTISOL IN GILTS

The effects of short-term restraint stress, by means of snaring, on plasma concentrations of catecholamines, beta-endorphin, and cortisol were studied in 6 gilts. A catheter was inserted into the jugular vein, and 2 blood samples were collected before onset of stress. Thereafter, a hog snare was applied and blood samples were collected at 0.5, 2, and 3.5 minutes after the start of snaring. Plasma epinephrine and norepinephrine concentrations increased (P < 0.001) within 0.5 minute after start of restraint and decreased thereafter. Plasma concentration of beta-endorphin increased (P < 0.05) within 2 minutes after start of restraint, whereas that of cortisol increased (P < 0.05) 3.5 minutes after start of restraint. Taken together, short-term stress, such as snaring, may increase the plasma concentration of catecholamines, beta-endorphin, and cortisol in pigs.