Motility and Fertilizing Capacities of Fowl Sperm in the Excretory Ducts

Young 1 showed clearly that spermatozoa of mammals require and undergo a “ripening” process after formation, while being transported through the seminiferous tubules and epididymis during which they acquire not only the power of movement but also the ability to fertilize eggs of their own species.

Certain fundamental differences exist between the anatomy and biology of the avian and mammalian testis which make pertinent the question of just how analogous are the processes underlying sperm physiology in the two classes.

Spermatozoa removed from the testes, epididymides and vas deferens of 30 males of the domestic fowl have been examined for motility when suspended in either Ringer's solution or the diluent recommended by Baker. 2 Using the motility classifications of Moore 3 the activity of sperm from the testis, epididymis and vas deferens was found to be x, xx or xxx and xxxx respectively. There was practically no overlapping in motility between the 3 levels. Thus, in general, the attainment of the capacity for movement by the formed spermatozoa in the fowl parallels that demonstrated for mammals; capacity for movement is minimal or only indicated in the testis, increases somewhat in the small epididymis and reaches maximal only in the vas deferens.

When tested by artificial insemination using infertile females a differential fertilizing ability was demonstrated; the fertilizing ability being directly correlated with the power of movement. The data are summarized in Table I.

Spermatozoa were secured from the respective portions of the reproductive tract immediately after the males were killed, diluted with equal parts of Ringer's or Baker's solutions and introduced directly into the oviduct of the females. The distal end of the oviduct was exposed through the anus by pressure applied simultaneously with the open hand to the posterior and lateral abdominal walls.