Heart Rate and Stress Hormone Responses of Sheep to Road Transport Following Two Different Loading Procedures
This study was designed to investigate the physiological responses induced in sheep (n = 18) by two different loading techniques followed by a short road journey. All animals were prepared with venous catheters, to minimize the disturbing effects of blood sampling, and nine sheep were
fitted with heart rate monitors. The animals were loaded onto a transport vehicle in groups of three, alternately using a conventional tailgate ramp or a crate raised with a hydraulic lift. When all of the sheep were loaded, they were taken on a journey lasting 195min. Blood samples were collected
in the home pen, directly after loading, and at 15min intervals during the journey. Measurements were made of plasma concentrations of cortisol, prolactin and catecholamines (adrenaline and noradrenaline). The results indicated that heart rate increased during loading, regardless of the method
used. No changes in concentrations of cortisol or the catecholamines were detected, although a small increase in prolactin was noted when animals were loaded using the ramp. During transport, all sheep exhibited increases in plasma cortisol concentrations which were greatest during the first
2h of the journey. The results suggest that, under the conditions employed in this experiment, the effects of the two loading procedures were similar and that transport appeared to be more stressful than loading.