THE DISTRIBUTION OF POTASSIUM AND SODIUM CONCENTRATIONS IN THE ERYTHROCYTES OF SOME BREEDS OF CATTLE

The distribution of erythrocyte potassium and sodium concentrations wa s studied in Sayaguesa (n = 150), Brown Swiss (n = 163) and two popula tions of Avilena-Negra Iberica cattle (n = 141 and 141 respectively). No polymorphism was detected for red-cell cation content in any of the breeds investigated. Mean values of potassium concentrations varied b etween 21.42 and 24.92 mmol/l red cells, those of sodium contents rang ing from 77.50-93.44 mmol/l. The cattle studied can thus be considered as belonging to the 'low potassium' (LK) type. Significant difference s were found both in potassium and sodium concentrations between one o f the populations of Avilena-Negra Iberica and the other groups examin ed. Mean values of sodium levels in Brown Swiss were also significantl y different from the other groups.