Selenium concentration in the blood of ruminants grazing in Northern New South Wales. 2. Relationship with geological, pedological and other variables

Abstract

Selenium concentrations in blood from cattle from 794 farms in northern New South Wales were classified on the basis of underlying parent material, soil type, altitude and rainfall. Blood selenium concentrations declined from west to east, and with increasing rainfall and altitude; low concentrations were particularly evident on both acid and basic igneous rocks. There were significant differences between basalts in different locations and between particular plutonic bodies. Cattle grazing on soils with contrasting and gradational profiles generally had lower selenium concentrations than those grazing on soils with uniform profiles. Podzolic soils and chocolate-prairie and kraznozem-chocolate soil associations were present in areas with low blood selenium concentrations.