Semen was diluted 1:9 with egg yolk-citrate medium containing 0.31-3.1 M (final concentration) formamide, butyramide, acetamide, propionamide, dimethylformamide, lactamide, malomide, ethylene glycol, trimethylene glycol, dimethylsulfoxide (DMSO) or glycerol. After 30 min incubation at 20.degree. C, sperm motility was superior in hypertonic solutions of acetamide, lactamide, DMSO, trimethylene glycol and ethylene glycol. Some of these compounds were added to semen diluted 1:2 in an isotonic egg-yolk-glucose-lactose-raffinose solution and frozen by the pellet method. Relatively good motility survival was obtained in 1.0 M DMSO, lactamide or acetamide. Dimethylformamide (0.5 M), ethylene glycol (0.5-1.5 M), trimethylene glycol (1.5 M) and propionamide (0.75 M) gave some protection. Insemination of does with semen frozen and thawed with 1.0 M DMSO, lactamide or acetamide gave fertilization rates of 68-88% and 84% (38/45) of does gave birth to an average of 5.3 young.