Non-invasive collection of ejaculates from the common marmoset (Callithrixjacchus) using penile vibrostimulation

Penile vibrostimulation (PVS), a noninvasive repeatable method, has been sh own in the squirrel monkey to yield semen of higher quality than rectal pro be electro-ejaculation (RPE). The present study aimed at establishing the c onditions for PVS to collect ejaculates from marmoset monkeys. Ten adult ma les were trained on the appropriate handling before each was subject to six to 12 PVS tests. Ejaculation was stimulated using a FertiCare(R) personal vibrator fitted with a 2 cm x 0.5 cm i.d. glass tube. The stimulus was repe atedly applied over a frequency of 75-95 Hz and amplitude of 1-2 mm for up to 20 min. Ejaculates were analyzed for volume, total sperm number, sperm c oncentration, and proportion of living and motile sperm. Ejaculates were ob tained in 31 of 88 PVS tests; 87.1% of the ejaculations occurred at 80-85 H z frequency and 1-1.5 mm amplitude. In 18 tests ejaculates were produced wi thin 49.7 seconds. Ejaculates were characterized by (mean values): volume 3 1.9 mul, total sperm number 34.2 x 10(6)/ejaculate, concentration 1,154.2 x 10(6) sperm/ml, live sperm 74.6%, motile sperm 59.6%. Total number and con centration of spermatozoa were significantly enhanced in singly living male s. PVS yielded three to four times more spermatozoa than comparable previou sly published values for RPE. Enhancing the success rate by preselecting ma les for responsiveness may render PVS the sperm collection method of choice in marmoset monkeys. (C) 2000 Wiley-Liss, Inc.