Objective—To compare the effect of semen extender
and seminal plasma on postthaw motility and filtration
through a glass wool-Sephadex (GWS) filter for frozen
Sample Population—7 stallions from which we collected
≥ 3 ejaculates/stallion.
Procedure—4 experiments were conducted to evaluate
postthaw quality of frozen stallion semen.
Kenney extender was compared with glucose-EDTA
extender by use of various dilution rates that resulted
in differing concentrations of seminal plasma. Stallions
known to produce semen with poor postthaw quality
were used to investigate whether a particular extender
or dilution rate could improve ability of such semen
to survive freeze-thaw procedures.
Results—Use of Kenney extender as the centrifugation
extender significantly improved postthaw motility
and GWS filtration, compared with glucose-EDTA.
Extending semen at a dilution of 1:3 was significantly
better than 1:1 for both motility and GWS filtration. In
addition, including seminal plasma at a concentration
of 5% in the cryopreserved semen resulted in significantly
higher yield of spermatozoa after GWS filtration,
compared with complete removal of SP or use of
seminal plasma at 25%. Lastly, semen with poor
postthaw quality had significantly improved postthaw
quality in regard to motility and GWS filtration when
semen was frozen with seminal plasma at a concentration
of 5%, compared with semen frozen with
seminal plasma at a concentration of 25%.
Conclusion and Clinical Relevance—Use of Kenney
extender at a high dilution (≥ 1:3) immediately after collection
of semen can improve postthaw quality of
frozen stallion semen. (Am J Vet Res