Abstract
The protective effect of egg yolk citrate, egg yolk skimmed milk, and egg yolk lactose extenders on the sperm cell against freezing injury was studied using Ossimi and Rahmani rams. Advanced motility, dead and coiled tail percentages of fresh spermatozoa did not differ significantly between the two breeds. Freezing caused a highly significant increase in dead and coiled tail percentages of spermatozoa diluted with various extenders. Unsaponifiable matter of fresh spermatozoa of both breeds contained various hydrocarbons and sterols with C 26, C 24 and cholesterol being the basic compounds. The unsaponifiables distribution could be used to characterize the spermatozoal origin. Changes in total sterols/total hydrocarbons ratios of the unsaponifiables were occurred after freezing of both breeds using the three extenders. Cholesterol content of fresh spermatozoa and the changes in physical properties of spermatozoa of both breeds indicated that the freezability of Ossimi semen was better than that of Rahmani. Also, the changes occurred in physical properties and total sterols/total hydrocarbons ratios showed that egg yolk lactose extender was better than egg yolk skimmed milk and egg yolk citrate extenders for sperm protection against freezing injury.