Sperm counts. Method Volume Sperm count Motility Penile Massage 16.9 (0.2-50) 7.1 (0-208) 15.8 (0-80) AV 46.7 (30-60) - Rectal massage 3.0 55 30 Electroejaculation - Rectal&Penile massage 10.6 (2-20) 142.5 (0.2-2700) 50 (30-80) Electroejaculation 0.7 (0.1-2) 186.4 (5-500) 73 (70-80) & penile massage bicornis electroejaculated 15 200 million bicornis electroejaculated 20 1 million bicornis manual stimulated 62.2 15.0 million simum manual 0.7 10.0 million unicornis manual 8.0 13,900 million End
A penile massage collection proceeded with two operators kneeling at the rear of the rhino to massage the penis. Rubbing the medial aspects of the rear legs and the stomach always induced let-down of the penis from the sheath so it could be massaged directly. When released from the sheath, the semi-erect penis curved caudally. Proximal to the curve were lateral, longitudinal folds. After the penis was released from the sheath, it was washed with warm water. Silicone gel was then smeared on the distal 15-20 cm of the penis (end of penis to beginning of lateral folds), but the penile tip was kept free of lubricant. Complete erection was induced by rubbing back and forth on the top and bottom of this area with one hand. Gentle rubbing would become more vigorous as the penis became erect. With erection, the curve of the penis straightened, swinging the tip of the penis forward. The lateral folds (20-25 cm in length) expanded into slightly cupped projections extending from the middle of the penis. A 60 cc syringe case was held over the tip of the penis to collect the ejaculate. Forceful ejaculations of seminal fluid occurred as the penis became fully erect. Occasionally, shaking of the back legs and thrusting of the penis would occur. Another operator would help support the penis as it became fully erect. The entire length of the fully erect penis was 60-70 cm. The tip of the penis needed to be covered at all times during stimulation since semen could squirt or dripple out at any time. After a forceful ejaculation, the penis would relax and the animal would not usually remain still for further manipulation. Periods to and ejaculation lasted from 10-20 minutes. If ejaculation did not occur at full erection, the penis was allowed to relax. The process was repeated until the rhino would no longer stand still, which usually occurred in 40-60 minutes. Results. The rhino was the most receptive to penile massage. It was the most frequently successful of collection methods. Fluids from this method were characteristically clear and viscous with poor sperm concentration. Ejaculate volumes obtained from penile massage were consistently higher than the other methods investigated.
Two different water-filled artificial vaginas (AV) were constructed. A water-filled AV similar to a standard domestic animal AV which provides the warmth and pressure needed to induce ejaculation was developed. Briefly, an 18 cm x 50 cm PVC pipe was used as support for two 15 cm latex liners: one inside the other. The outside liner was stretched over each end of the pipe. The cavity between the latex and pipe was then approximately half-filled with warm water (ca. 35?C - 45? C) through a sealable hole in the pipe. The other latex insert was stretched over one end of the pipe, with the other end sealed (vulcanized) except for a 3 cm hole that could be stretched over a 50 cc centrifuge tube (polystyrene, American Scientific, McGraw-Park, IL). Because the AV weighed approximately 25-30 lb when filled, handles were fitted on both sides so it could be held by more than one operator. Lubricant was then applied to the interior of the AV. This AV covered the end and lateral folds of the erect penis. A modified AV was developed based on the experience of the previous AV. A 15 cm diameter latex liner was doubled over and vulcanized together with a 15 cm diameter metal ring (within the latex) attached to a wooden handle. 'I'his handle allowed this 50 cm long AV to be held by only one operator. The other end of the folded liner was also vulcanized closed, except for an opening that could be stretched onto a 50 cc centrifuge tube. This AV was constructed to only cover the distal part (15-20 cm) of the penis. To determine the optimum temperature needed to induce ejaculation, two different temperature ranges (35-40 and 40-45 ?C) were employed in the AV. Results. Inducing a fully erect penis by penile massage was required before an AV could be fitted. AVs intended to cover the penis had to have diameters large enough for the width of the penis when the lateral folds expanded into projections. The initial AV's construction with PVC pipe and its snug fit often resulted in abrasion to these lateral projections. This AV was abandoned for the modified lighter and all-latex AV that could be handled by one operator. Although trauma to the penis was relieved by the modified AV, maintaining the erection after fitting the AV was still a problem. Only three of ten attempts with the AVs resulted in ejaculates. These samples had high volumes but poor sperm concentrations. These ejaculates occurred when the AV temperature was between 40-45?C.
The entire length of the fully erect penis was 60-70 cm.
Rhinoceros unicornis. He was healthy except for penetrating cracks in his rear foot pads that periodically inflamed into supportive erosive pododermatitis causing him to limp.
For rectal massage, an operator inserted a plastic-sleeved, lubricated hand through the anal sphincter and then manually massaged the accessory glands through the mucosa of the caudal rectum. The prostate and bulbourethral ogland, which were about 10-15 cm proximally to the anal sphincter, were massaged with rhythmic side-to-side downward pressure by the operator's fist. Massage proceeded in 5 minute intervals with resting 1-2 minutes between intervals. Total time for massage never exceeded 15-20 minutes. Results. The rhino was initially reluctant (flicking his tail and walking around) to have a plastic-sleeved, lubricated hand pass through the anus, but after four to five sessions, he became receptive to palpation. The rhino's penis would drop from the sheath during rectal massage, but never became fully erect. Fluid drippled from the penis only once, after it had dropped from the sheath during rectal massage. Although the total stimulation period was not shortened by combining rectal and penile procedures, the seminal fluids obtained by rectal massage followed with penile massage had higher sperm concentrations than penile massage alone.
Standard electrical probes used for domestic animals could not be utilized since they usually rolled in the gas-expanded rectum of the rhino. Because of this, the electrodes would inter-mittently lose contact with the rectal mucosa and therefore current could not be effectively controlled. The development of an inflatable rectal probe allowed complete and secure contact of electrodes to the mucosa. After placing the probe in the rectum, a sturdy 28 cm diameter balloon taped securely to the body of the probe (2.5 cm O.D. x 60 cm PVC pipe) was inflated with an air-mattress hand pump. The balloon pressed three loosely held (by wire) encircling copper electrode strips (25 cm x 4 cm) into contact with the mucosa. Air in the balloon was retained by a PVC hydrate-type cutoff valve. A 0.8 cm tube through the entire body of the probe allowed intestinal gas to exit without filling the rectum. Thus, the probe remained in contact with the mucosa. After inflating the balloon until the probe was in contact with the rectal mucosa, the cutoff valve was closed. The hand pump was removed and electrode leads were connected to wires hanging from the ceiling. The rhino was then free to move around the exhibit area during electrical stimulation by a 20 cycle electroejaculation machine. Three second sine wave pattern stimuli were applied at the 2V, 40 mA level for two series of 60-80 pulses each. With a 5 minute rest interval between series, the total procedure took from 10-15 minutes. The procedure was terminated if the animal became irritated. Results. The inflatable probe was easily inserted and removed when deflated. Electrical pulses at the 2V level were kept consistent as monitored by the strip chart patterns , but amperages varied between 40-50 mA during stimulation. Electrical stimulation by itself did not produce erection or ejaculation. The animal would stand or walk around his cage and occasional muscle contractions were seen in his rear legs. He did not become agitated (flicking his ears, rapid movement) unless amperages rose above 50 mA, and at that point the procedure was then terminated. Electrical stimulation followed by penile massage produced sperm counts comparable to the combination of rectal and penile massage. Total sperm counts from this combination were lower than rectal and penile massage probably due to low sample volumes obtained. Following electroejaculation, longer massage periods (20-30 minutes) were necessary to induce let-down of the penis from the sheath, in comparison to when only penile massage was performed. Ejaculates were not forceful and the volumes were small but the penis became erect. The animal was always restless following electroejaculation. so penile massage trials were not repeated..
