A note on copper retention by pigs fed on various protein sources

Abstract

Since, under Irish conditions, the source of protein used in pig rations often varies from one area to another, an experiment was conducted to determine the accumulation of copper in the tissues of pigs given the commonly-usedprotein sources in diets containing 250 ppm of supplemental copper. The protein sources compared were (a) white-fish meal (370 ppm Cu), (b) soya bean meal (17 ppm. Cu), (c) roller-dried skim milk (2 ppm Cu), and (d) a mixture of soya bean meal and meat and bone meal (5 ppm Cu) (Table 1). The minerals, vitamins and copper sulphate were premixed with about 5 kg. of barley and distributed over the total feed before mixing. The copper sulphate was sieved to remove coarse particles. Analyses of complete feed mixtures are shown in Table 1. As far as possible, the rations were balanced for crude protein, calcium and phosphorus.

Copper, molybdenum and sulphur contents of oats and barley in relation to chronic copper poisoning in housed sheep

“…The work of Poole (1967) would tend to rule out environmental factors as providing a satisfactory explanation for any increased accumulation of copper in sheep kept indoors. Among dietary factors which affect copper metabolism the effect of protein lias been investigated, but the evidence would seem to be equivocal, different protein sources apparently giving different results (McPherson & Hemingway, 1965;O'Donovan, Spillane & O'Grady, 1966;Todd, 1969). The interactions of molybdenum and inorganic sulphate on copper metabolism in ruminants havebeen known for many years (Dick & Bull, 1945;Dick, 1953Dick, , 1954 and both copper deficiency f Present address: Agricultural and Food Chemistry Department, Queen's University, Belfast and Ministry of Agriculture for Northern Ireland.…”