Semen Collection by Rectal Electroejaculation of the Domestic Fowl

Abstract

Some trials were made to develop a method for collection of semen of birds by rectal electroejaculation.1) Cocks of the Single Comb White Leghorn were used as the experimental animals.2) Rectal probes for electroejaculation were made of hollow plastic rods, about 8mm in diameter and about 35mm in length. Three ring electrodes or a single pair of longitudinal strip electrodes were wired on the probe, an L-shaped slender but steady handle was attached to the probe, then electric wires were cemented to the handle with epoxy resin.3) Both legs of a cock were tied with a looped string and the legs were pulled down-ward along the foot of an operator sitting on a chair by the other end of the string. The cock was set on that knee of the operator by the animal's breast and thigh, facing it's tail toward the operator, then held in a posture of tail side-up.4) A rectal probe was inserted into the cock's rectum standing the handle towards the tail. An electroejaculation stimulator constructed for applying to the goat or the sheep was set at 40 volts and zero mA at start, and then the current was increased gradually up to the point where eversion of the cloaca was obtained. Usually the threshold current was under 10 mA. Excreted feces and urine were removed with warmed diluent or some physiological solution, and excessive solution was removed with absorbent cotton. As semen ejaculated with transparent fluid from erected copulatory organs when the bilateral side of everted cloaca was gently pushed by the thumb and the other fingers, a semen sample was collected into a test tube quickly. The probe was pulled out from the cock's rectum after the electric current was turned off.5) If a seman sample was collected by this method, semen volume was in the range of 0.1 to 1.1 ml, the concentration of spermatozoa was 0.8 to 2.3 billions per ml and the motility of spermatozoa was about 4 assigning relative values of 0 to 5 by CLARK and SHAFF-FNER7).6) The birds hardly showed any signs of pain when the handling of all procedures of semen collection were performed with circumspection.