Characterization of semen collected from beagles and captive Japanese black bears (Ursus thibetanus japonicus)

This study characterized semen collected from the Japanese black bear, Ursu s thibetanus japonicus, to provide information on semen cryopreservation fo r artificial breeding. Preliminary studies using a beagle dog as the model species showed that sperm concentration and total sperm count were lower in semen collected by electroejaculation than in semen collected by digital m anipulation, but that sperm motility, viability and morphology were similar . Characterization of semen obtained from Japanese black bears by electroej aculation under general anesthesia revealed that semen volume and total num ber of spermatozoa collected were lower; but that sperm concentration, moti lity, viability and morphology were equivalent to those reported in other u rsids. When semen was collected via a catheter inserted into the urethra du ring the stimulation for ejaculation, the sperm concentration, total sperm count and motility were relatively higher than when semen was collected dir ectly in a test tube. Specific normal semen characteristics (mean +/- SEM) were pH, 7.6 +/- 0.0; volume, 0.212 +/- 0.038 mL; sperm concentration 361 /- 100 x 10(6)/mL; total sperm count, 84.0 +/- 32.2 x 10(6); +++ motility, 30 +/- 5%; motility, 77 +/- 3%; viability 77 +/- 2%; and abnormal morpholog y, 11 +/- 2%. These results suggest that semen can be collected from Japane se black bears by electroejaculation. (C) 2001 by Elsevier Science Inc.