Abstract
Semen was collected during the breeding season from rams by electroejaculation from two native (13 Najdi and 8 Naemi) and three imported (6 Merino, 7 Somalian and 9 Sudanese) sheep breeds. There was a marked reduction in sperm concentration and the percentage live spermatozoa (p<0.01) produced by the Somalian (Barbari) and Sudanese (Sawakni) breeds. On the other hand, these two breeds showed the highest percentage of spermatozoal individual motility (p<0.05) and the highest concentrations of sodium (Na) chloride (Cl) and inorganic phosphorus (P) in the whole semen, seminal plasma and spermatozoa. Superior sperm density, percentage live spermatozoa and seminal concentrations of potassium (K) and calcium (Ca) were evidenced in the Najdi, Naemi and to a lesser extent, in the Merino rams. The biological effects of these inorganic constituents, together with magnesium (Mg), in the semen on semen quality should be considered in the interpretation of the results obtained in the fertility evaluation of the various ram breeds.