Effects of Egg Yolk Source on the Cryopreservation of Stallion Semen

The objective of this study was first to compare regular chicken and low cholesterol, omega 3 chicken egg yolk and then compare turkey, duck, omega 3 chicken, and regular chicken egg yolk for the use in the cryopreservation of stallion semen. Following collection, aliquots of each ejaculate were centrifuged and resuspended in lactose-EDTA with 18, 20, 22% chicken or low cholesterol, omega 3 chicken egg yolk (Exp. 1) or lactose-EDTA with 20% turkey, duck, omega 3 chicken, chicken egg yolk or EZ Freezin (Animal Reproduction Services, Chino, CA, U.S.A.) (Exp. 2). Aliquots were frozen and stored in liquid nitrogen until evaluation. There was no significant stallion or treatment effect on post-thaw motility when low cholesterol, omega 3 egg yolk was used over the regular chicken egg yolk in Experiment 1. Post-thaw progressive motility was highest in the spermatozoa frozen in turkey egg yolk extender (P≤0.05). Further investigation in regards to the fertility of spermatozoa frozen in turkey egg yolk extenders and the use of turkey egg yolk in slow freeze extenders is warranted