Deposition of copper, manganese, selenium and zinc in Merino sheep

Abstract

Ninety-six fine-wool Merino ewes, ranging in age from newly born to 74 months and in liveweight from 2.9 to 54.5 kg, were slaughtered and their livers and kidneys removed. The livers, kidneys and the remainder of the carcasses were minced separately and analysed for copper (Cu), manganese (Mn), selenium (Se) and zinc (Zn). Some of the ewes had previously been supplemented with Se or Cu. Regression relationships were calculated between the Cu, Mn, Se and Zn contents of the whole body and liveweight, or, in the case of Cu and Se, liveweight and the product of blood Se or liver Cu concentrations and liveweight. The relationships were used to derive mineral requirements for growth by using a factorial method, and the values obtained were compared with those reported in the literature. The quantities of Cu, Mn, Se and Zn stored in the liver and kidney, expressed as a proportion of whole body storage, were calculated and related to liveweight and other variables. Relationships for predicting liver and kidney weights from liveweight are also presented.