Viability of diluted dog spermatozoa in vitro

Summary. The motility of dog spermatozoa is depressed by high dilution. Dog spermatozoa survived best in a chloride diluent, buffered with phosphate. Citrate, tartrate and peptone diluents were less favour¬ able. Adding 2 to 25 % prostatic fluid to diluents partially prevented the effects of dilution on dog spermatozoa, but motility was depressed by neat prostatic fluid. There was little evidence for loss of protective substances from dog spermatozoa when left overnight, or after repeated freezing and thawing. Bovine globulin, casein, egg albumin and alanine were even more effective than prostatic fluid in preventing the dilution phenomenon, and motility in their presence was as good as in con¬ centrated suspensions. Egg albumin, casein, acacia, serine and alanine improved the motility of washed dog spermatozoa