Effects of Intradermally Injected and Topically Applied Mouse Epidermal Growth Factor on Wool Growth, Skin and Wool Follicles of Merino Sheep

In this study, intradermal injections of mouse epidermal growth factor (mEGF) in Merino sheep led to dose-dependent changes in wool follicles and fibers, including reduced follicle bulb size, disturbed cuticle formation, and induction of catagen with fiber shedding. Follicle regeneration began by day 7, and the epidermis, initially thicker and more parakeratotic, returned to near normal by day 14. Additionally, there were persistent increases in sebaceous gland size and delayed increases in sweat gland size. In contrast, saline injections had no effect on follicle activity.