a. r. vaferi

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.