
Group of animal consist of 300 Awassi ewes, 32 rams and 322 off spring were typed for blood potassium and hemoglobin , HK gene frequencies for ewes, rams, and lambs were of the order of 0.89, 0.93 and 0.88, respectively; for the HbB gene the corresponding frequencies were related 0.98, 1.00 and 0.99, respectively. B HK (High potassium, Hb type B) ewes showed a significantly higher lambing percentage, fleece weight, fiber diameter, fleece wax percentage and alkali solubility percentage, 98.5%, 20kg, 29.6µ, 2.2% and 7.6% corresponding with related 95.5%, 1.8kg, 28.6µ, 1.8% and 7.1% of B LK type respectively. B LK (Low potassium, Hb type B) ewes produced significantly more female lambs while B LK lambs, compared with B HK ones, had significantly higher birth and weaning weights. The association between B HK types and fitness was proposed as the explanation of the high gene frequency of this type.