Glutathione peroxidase and selenium in sheep. II.* The relationship between glutathione peroxidase and selenium-responsive unthriftiness in Merino lambs

Abstract

Low erythrocyte activities of the selenium-containing enzyme glutathione peroxidase were found in Merino lambs in an area of the Strathbogie Ranges in central Victoria where selenium-responsive conditions have previously been reported. Body weight gain trials conducted over 10 properties in the above area demonstrated that the severity of selenium-responsive unthriftiness was significantly correlated with the erythrocyte glutathione peroxidase activity (r = – 0.95, P <: 0.001). Positive body weight responses to selenium treatment were only observed in lambs with erythrocyte glutathione peroxidase activities less than 30 U/g Hb prior to selenium treatment. These findings indicate that measurement of erythrocyte glutathione peroxidase activity provides a convenient index of the selenium status in sheep. ________________ *Part I, Aust. J. Agric. Res., 30: 695 (1979).