Effect of adding seminal plasma on coated sperm of Taleshi ram in the presence of egg yolk and without it

In order to study the effect of the presence of egg yolk and adding seminal plasma to coated sperm، the semen were collected from 4 Taleshi rams by using artificial vagina. To coat the sperm، semen was collected within the tube containing Tris-fructose-15% egg yolk. After the initial evaluation، the samples are mixed and centrifuged. After removing supernatant and diluting، samples were divided into 3 equal parts; they were cooled to 4°C and incubated for 44 hours. Three methods (R، M and N) were performed to add seminal plasma. In R method، sample was centrifuged and supernatant were removed. In M method، sample was centrifuged and mixed with the supernatant. In N method، nothing was done and sample was kept at 4°C. Sample، which obtained from each method، was split into three equal parts after that the amount of zero، 10 and 20% seminal plasma were added and aliquots incubated at 4°C. Sperm motility، functional membrane integrity، viability and acrosome integrity were estimated after 4 hours. The lowest of sperm motility (10. 83%) and viability (57. 58%) were observed by R method (P<0. 05). The functional membrane integrity was higher in N method (61. 33%) than R method (52%; P<0. 05) and there was no difference between R method or N method and M method. The methods did not effect on the acrosome integrity. Therefore، removing egg yolk was not useful for coated ram spermatozoa after storage at 4°C.