EFFECT OF INTAKE OF COPPER, MOLYBDENUM AND SULPHATE ON COPPER METABOLISM IN SHEEP .4. PRODUCTION OF CONGENITAL AND DELAYED SWAYBACK

Feeding a low Cu diet (1 μg. Cu/g.) to ewes throughout a second pregnancy and the following lactation produced a mild transient anaemia in both ewe and lamb and there was a low incidence of delayed swayback. With Mo (25 μg./g.) and SO4 (5·3 g./kg.) added, severe anaemia and reproductive failure developed in the ewe in the first pregnancy; some of their lambs had congenital swayback, but the incidence varied greatly in three successive years and possible reasons for this are discussed. A dietary Cu supplement (10 μg./g.) only slightly reduced the Cu depletion of ewe and lamb tissues caused by Mo + SO4, but the effect was sufficient to prevent the development of clinical abnormalities after two pregnancies. © 1969.