A Comparison of the Ability of Certain Egg Yolk Diluents to Maintain Optimum Osmotic Conditions during the Storage of Bull Semen

Summary Semen specimens from healthy dairy bulls were extended with six diluents, stored at 4 to 7° C. and examined daily for both motility and freezing point depression. One of these diluents, the egg yolk-citrate diluter, failed to maintain the osmotic pressure of the extended semen within the range suggested by Pursley and Herman as optimal for semen diluters. The other diluents used in commercial artificial insemination did maintain the osmotic pressure within these limits, and one of these, the egg yolk-glucose-NaHCO 3 diluter developed by Kampschmidt et al. (7) , maintained the osmotic pressure along the line of mean freezing point depression of semen, a point further strengthened by its superior motility maintenance during the storage period. It is suggested that added glucose aids in the maintenance of storage osmotic pressure within narrow limits and thus may have an influence upon the viability of bull spermatozoa during a prolonged storage period.