Effect of Egg Yolk and Removal of Seminal Fluid on Semen Cryopreservation in Norduz Goat

Cryopreservation of goat spermatozoa is a valuable tool for genetic management. Previous studies have shown the frezeeablity of spermatozoa from various goat breeds but also have difficulties with available protocols. Therefore, we want to investigate the effects of centrifugation and different egg yolk ratios (5% and 10%) on spermatological parameters of Norduz goat spermatozoa. A total number of 20 ejaculates were collected with an artificial vagina from 5 mature Norduz male goats (3 and 4 years of age) twice a week, during the breeding season twice a week. Each ejaculate were divided into four equal aliquots. The samples were then diluted 1:9 (v:v) in washing solution, centrifuged at 600 g for 10 min at room temperature and the supernatant discarded for sperm washing process. Fresh and washed samples then were diluted with skim milk containing % 5 egg yolk and %10 egg yolk, respectively. Extended samples were loaded into 0.25 ml straws, equilibrated at that 4 C for 2h, frozen in nitrogen vapour for 10 min and plunged into liquid nitrogen. Samples were assessed for motility and acrosome integrity upon collection and after freezing and thawing. Removel of seminal fluid had detrimental effects on motility and percentage of total abnormal spermatozoa (p<0,05). In conclusion, it is not recommended to centrifuge the ejaculates form Norduz goats prior to conducting freezing-thawing procedures using a skim milk extender.