Abstracts of Communications

Abstract

Anaemia, achromotrichia, neonatal ataxia, loss of wool crimp and bone fractures have each been associated with copper deficiency in the sheep under field conditions (Underwood, 1962). There is, however, no information on the effect of Cu depletion per se on growth, development and reproduction in the sheep. We have developed a diet containing only 1 -2 ppm dry matter Cu, using the following components (yo): oat husks 37, maize starch 17, sucrose 16, dried skim milk 16, urea 2.1, arachis oil 2.5, KHC03 2.1, NaCl 1-6, MgO 0.5, added water 42, + trace minerals and vitamins A, D and E. Two groups of ten lambs, weighing initially about 18 kg, have been given this diet for 64 weeks and one group also received a supplement of 10 ppm Cu. The lambs were kept in metal-free pens and given deionized water. Both groups increased in live weight at about 0.9 kglweek and consumed 12.1 kgfood/ kg live-weight gain up to the 48th week. Mean values for the Cu content of the erythrocytes and plasma in the two groups are given in Table I . Plasma Cu concentrations fell most rapidly in unsupplemented female lambs reaching a minimum of about 10 pg/zoo ml after 28 weeks, a value associated with deficiency symptoms in the field (Underwood, 1962) and some 20 pg/Ioo ml lower than that found in the male lambs. The decline in erythrocyte Cu was less rapid than that in plasma but was also greater in female lambs. Loss of wool crimp was suspected after 24 weeks and by the 44th week a distinct band of poorly crimped wool was visible in three unsupplemented lambs with https://www.cambridge.org/core/terms. https://doi