The effect of sympathectomy on wool growth and catecholamine innervation of the skin in Wiltshire Horn sheep

Abstract

SummarySeven Wiltshire Horn rams were subjected to unilateral thoracic sympathectomy. Wool shedding was observed during the following 9 months. Fleece samples were collected on two occasions during winter from tattooed areas of skin on both the sympathectomized and unoperated sides. Skin samples were also taken from the sympathectomized and unoperated sides of the sheep during August and examined for catecholamine fluorescence using a fluorescence histochemical technique. While there was no difference in fleece casting between the sympathectomized and unoperated sides, there were increases in both wool growth and the number of brush end fibres on the sympathectomized side. Fluorescent histochemical evaluation of the skin samples revealed that the increases in shed fibres and wool growth were accompanied by a decrease in amine fluorescence in nonvascular tissue adjacent to the wool follicles.