Copper, Zinc and Molybdenum in Livers of Norwegian Cattle At Slaughter

Open Access
Publisher Website
Google Scholar
Abstract
The concentrations of copper, zinc and molybdenum were measured in samples of cattle liver from 10 slaughter-houses in Norway. A total of 335 samples were analysed. A clear accumulation of copper with age was found, the average copper level in the younger animals (≦ 3 years, n = 194) being 30 µg Cu/g liver wet weight, and in the older ones (> 3 years, n = 141) 59 µg Gu/g. The range in the copper values found was considerable, though significant differences between some of the districts were recorded. Copper concentrations were classified as low (≦10 µg Gu/g) in 9.6 % of the samples. Zinc showed no accumulation with age, nor were there any differences in zinc levels found in animals from different districts, the average level being 32 µg Zn/g liver wet weight. The picture was the same for molybdenum, no differences between age groups or districts being found. The average level was 1.0 µg Mo/g liver. There was no significant correlation between levels of copper, zinc or molybdenum. The supply of copper and zinc to cattle in Norway seems close to sufficient, but copper- and zinc-fortified mineral supplementation of cattle feed is still to be recommended. There seems to be no need for molybdenum supplementation in cattle.