Influence of Haemoglobin Type and Selenium Status on Peripheral Plasma Progesterone and Corticosteroid Concentration in Ewes Grazing Oestrogenic Pastures

Abstract

Peripheral plasma progesterone and corticosteroid concentrations were studied in ewes grazing oestrogenic pastures during oestrus, pregnancy and parturition in 1974 and during pregnancy in 1975. Haemoglobin (Hb) type A ewes had significantly higher mean corticosteroid concentrations than HbB ewes in both years. In 1974 the concentration of progesterone did not differ significantly between Hb types whilst in 1975 the concentration was significantly (P < 0·001) higher in HbA ewes.