Analysis of Deferent Duct Morphology in Turkeys Characterized as Low or High Semen Volume Producers1

ABSTRACT The objective of the present research was to clarify the basis for the difference in performance of turkey toms characterized as low or high semen volume producers. Variables measured included testicular weight, deferent duct semen volume, and deferent duct morphology based upon plastic casts. Three organizational patterns emerged after viewing plastic casts of deferent ducts: helical, serpentine, and randomly folded coil. The randomly folded coil was the principal pattern in deferent ducts from low and high semen volume producers alike. No difference in patterns was observed between low and high semen volume producers. Differential semen yield was attributed to a greater testicular mass along with a greater storage capacity of the deferent duct in high semen volume producers. However, deferent duct storage capacity appeared to be the predominant factor affecting semen yield. (Key words: turkey, semen, reproductive efficiency, deferent duct, ductus deferens