Abstract: Semen collection and sperm evaluation and addition of preservatives for increasing storage of sperm are essential for successful artificial insemination. This study was conducted on 4 rams (2 Ghezel Merinos and 2 Merinos Moghani) rams to evaluate the effect of 2 liquid diluters (1-egg yolk- citrate, 2-milk) in Khalat poshan research station. Average age of rams was 2-3 years. After rams were trained to serve the artificial insemination, semen samples were collected weekly. It was started from October 2011 to June 2012. After collected semen was mixed with liquid diluents and was stored in a refrigerator for 8 days. Semen after diluting and storage were assessed for pH, viability and progressive motion. Effect of diluent and storage day on pH, viability and progressive motion of sperm were significant (P< 0.01). With the increasing storage day pH, viability and motility progressive of sperm decreased. The success of diluent of milk has been attributed to its protein fraction, which may act as a buffer against changes in pH and as a chelating agent against any heavy metals present. The success of citrate has been attributed that may act as a buffer against changes in pH. The egg-yolk providing protection of sperm against cold shock. This study showed Diluent of citrate-egg yolk had a better sperm protection ability than milk based extenders following 8 day of storage – according to sperm motility, pH and sperm viability.
Keywords: Semen, Diluter, Liquid, Viability, Progressive motility.