抄録
Four adult Hokkaido brown bears were used as semen donors, and semen characteristics were examined before freezing and after thawing. A total of 10 electroejaculates were diluted with Tris-egg yolk extender and cooled to 4°C over 90 min. Spermatozoa were equilibrated with 4.7% glycerol for 80 min. Semen packed in 0.25 ml plastic straws were frozen with liquid nitrogen vapor. Percentages (mean ± SD) of motile and live sperm were 96 ± 2 and 86.5 ± 7.2% before freezing, and 43 ± 5 and 67.4 ± 3.9% after thawing, respectively. Although the number of progressively motile sperm after thawing varied among samples (1.8 ± 1.2 × 108 cells/ejaculate), frozen semen in the present study might serve for artificial insemination.
