In experiments involving concurrent insemination of equal quantities of
spermatozoa from both strains into the same hens, these authors reported that the
progeny derived from frozen spermatozoa were only 20% as frequent as those from
unfrozen but glycerolated and centrifuged spermatozoa. The conclusion from these
studies is that the freeze-thawing process itself results in 80% loss of fertilizing ability,
whilst the process of glycerolization, dilution, centrifugation and resuspension causes a
further loss of approximately 18%. These estimations were also given credence by the
finding that the numbers of frozen-thawed spermatozoa found in the OPL of laid eggs
from inseminated hens was 2.2% of that of untreated spermatozoa