Different egg yolk concentrations on the quality of the canine semen diluted in ACP-106 and chilled under 4 °C

Semen chilling procedure preserves gametes without reaching the freezing point, which induces deleterious intracellular changes that affect viability and fertilizing potency of spermatozoa. The aim of this work was to compare different egg yolk concentration for dog semen chilling at 5 °C extended in ACP ® -106. ACP-Ejaculated of dogs (n=10) were diluted and chilled in ACP -106 without (control group) or containing 5, 10 or 20% egg yolk. Was observed a significant reduction in extender pH using 20% egg yolk on the second day of chilling and after the third day of chilling when using 5 and 10% egg yolk. At the first day of chilling 20% egg yolk extender result in better sperm motility in comparing 5% egg yolk group. After five days of storing, the use of 5 and 10% were inferior to the control group. The reduction on motility was significant at the first day of chilling in the control group, after two days on group with 5% egg yolk and after three days in the other groups. The vigor, sperm and acrossomal morphology, functional plasma membrane integrity were similar in all groups tested. In conclusion, the egg yolk influences the maintenance of the pH in the extender ACP-106 and that the canine semen can be efficiently conserved for up to two days using 10 or 20% egg yolk.