A comparative study on the cryogenic preservation of semen from the sandhill crane and the domestic fowl

SYNOPSIS: Recent findings on the cryogenic preservation of semen from the crane, Grus canadensis pratensis and the domestic fowl, Gallus domesticus, are compared. Highest levels of post-thaw motility for crane semen (55%) were obtained when semen was diluted 1:1 with the Beltsville Poultry Semen Extender (BPSE) and held for 30 min at 5 C before it was equilibrated with 4% dimethyl sulfoxide (DMSO) for 15 min. In contrast, post-thaw motility for fowl spermatozoa was highest (80%) when semen was diluted 1:3 with BPSE and held for 60 min at 5 C before it was equilibrated with 4% DMSO for 60 min. Post-thaw motility of spermatozoa of both species was highest when the following freezing rates were used: l C per min from +5 to -20 C, 50 C per min from -20 to -80 C, then plunging into liquid nitrogen which resulted in a rate of 160 C per min from -80 to -196 C. One of four crane eggs resulting from insemination with frozen-thawed semen was fertile, whereas 27 of 55 fowl eggs were fertile, but this difference may have been due largely to fewer spermatozoa being inseminated into the female crane than into the fowl.