An exploration of cryoprotective compounds for fowl spermatozoa

Glycerol is an effective cryoprotective for fowl spermatozoa, but after thawing the frozen semen it must be reduced in concentration from the level adequate to protect spermatozoa during freezing, otherwise it has a contraceptive action. A series of alternative cryoprotective compounds were tested for their effect on fertility when fowl spermatozoa were inseminated fresh in their presence. Under these circumstances dimethylsulphoxide, dimethylacetamide, ethane-diol, propane-diol and methylpyrrolidone did not depress fertility when used in concentrations equivalent to that of glycerol or in amounts reported previously to be non-toxic and adequate to protect cells during freezing. Dimethylacetamide was compared with propane-diol for use in freezing fowl semen and the former enabled encouraging levels of fertility to be obtained.