Surface Architectural Anatomy of The Penile and Preputial Epithelium of Bulls

Abstract

It has been a long held assumption that older bulls develop deeper folds or crypts in the epithelium covering the penis and prepuce than are found in their younger counterparts. These deeper crypts reportedly facilitate the carrier state of bovine venereal disease by providing a protected environment suitable for long term maintenance of infection. No published reports have been found to support this assumption. This study was conducted to characterize the surface architectural anatomy of the epithelium and epithelial crypts in younger and older bulls. This survey included Angus bulls sampled between December 2008 and March 2009. Bulls were placed into two groups of six according to age. Group 1 consisted of bulls 2 years of age, and group 2 consisted of bulls ≥ 5 years of age. Penile epithelium was collected from three anatomical locations (Proximal, Middle, and Distal) and tissue samples were prepared for examination by light microscopy and scanning electron microscopy. Three parameters were examined; 1) area of the epithelium per unit of linear measurement, 2) area encompassed by the folds, and 3) total number of folds per unit of linear measurement. Findings were then compared within and between the age groups. Results indicated that there are no significant differences in the area of the epithelium, area encompassed by the epithelial folds or total number of epithelial folds per unit of linear measurement between the two age groups.