Histology of lamb epididymal development.

To describe the distribution of the histological regions and their morphometry during epididymal development, 10 Corriedale lambs were castrated monthly from 90 to 180 days of age (n = 24), and their testes and epididymides were weighed. All animals were weighed monthly. Epididymides were divided into caput, corpus and cauda, and cut sagitally so that sections included all the length of the organ. The diameter of the epididymal duct, the smooth muscle depth and the epididymal epithelium height were measured. The quantitative histology of the ovine epididymal development was described. Epididymal development advanced from caput to cauda. The distribution of the histological regions varied according to epididymal weight. Transient histological regions were found during epididymal development. The present results indicate a new way of epididymal development in sheep, which courses from caput to cauda with transient histological regions appearing, varying in location and disappearing during ovine epididymis development.