Evaluation of quality of ram coated sperm after 72 hours storage at 4 °C and adding seminal plasma

This experiment was conducted to evaluate the addition of seminal plasma to coated spermatozoa after 72 h. Semen was collected from four Taleshi rams by artificial vagina. To prepare coated spermatozoa, semen was collected in tube containing Tris-fructose-15% egg yolk. After initial evaluation, the samples were mixed and centrifuged. After removal of supernatant and dilution, samples were divided into three sections, cooled to 4°C and stored for 68 hours. The first part was centrifuged and the supernatant was removed (Method I). The second section was centrifuged and the supernatant was mixed again (Method II). The third section was kept without change at 4°C (Method III). Samples were obtained from each method were divided into three equal parts, added 0, 10 and 20% of seminal plasma and incubated at 4°C. Sperm motility, viability, plasma membrane integrity, acrosome membrane integrity were evaluated after 4 hours. Sperm viability was higher in the presence of 0% seminal plasma (69/416%) than 20% seminal plasma (60/667%; P<0/05). The lowest sperm motility (11/667%), viability (59/167%) and plasma membrane integrity (48/168%) was observed in Method I (P<0/05). Methods did not affect the integrity of the acrosome membrane (P>0.05). Therefore, removing egg yolk and adding seminal plasma reduces coated sperm quality after 72 h storage.