Relationship of Ion Concentration to the Critical Temperatures During Freezing of Bull Spermatozoa

The over-all osmotic pressure of the extender is an important factor affecting the critical temperatures during which most of the damage to motility of bull spermatozoa occurs during freezing. For a 0.10 m Tris-yolk extender containing various levels of NaCl, KCl, or CaCl2 the critical temperature begins at −30 to −35C, and for a 0.30 m Tris solution containing corresponding salts this temperature begins at −10 to −15C.