Disclosed is a method for cryogenically preserving mammalian sperm, comprismg adding to the mammalian sperm, prior to cryopreservation, a composition that comprises at least one cryoprotectant, at least one membrane protcetant, and monothioglycerol, wherein mammalian sperm are effectively cryopreserved in the composition. Also disclosed is a method of producing cryopreserved mammalian sperm.