What is the length of a donkey whip? Donkey whip is usually long cylindrical, yellowish brown surface, dorsal and ventral sides of the middle of a longitudinal groove, foreskin hairless, glans is large, black and more wrinkled, there is a pair of testicles, testicles are rounded, the quality of hard and not easy to break, no transverse lines under the microscope. Donkey whip as a biological tissue, its length is not set in stone, will be affected by the growth environment, nutritional status, genetic factors and other factors.