Evaluation of the need of copper supplementation in intensively reared beef cattle

The aim of this investigation was to evaluate whether, in the nutritional management of commercial feedlots of NW Spain based mainly on concentrate feed from international raw materials, copper (Cu) supplementation is justified to maintain the physiological requirements. This was done by evaluating blood Cu parameters (serum Cu, whole blood Cu and serum caeruloplasmin), haematological (red blood cells, microhematocrit, haemoglobin, white blood cells, and thrombocytes), productive parameters (initial and final live weight, feed intake, average daily gain, carcass weight and performance and internal organs weight) and organic Cu accumulation at slaughter (liver, kidney, muscle, spleen and brain) in intensive beef cattle that received a standard diet with 15. mg/kg of Cu sulphate (Cu supplemented group, n = 10) and without Cu (non-supplemented group, n = 10) during all the productive cycle (growing and finishing periods and animals aged 12 to 36. weeks). In general Cu supplementation did not statistically affect blood Cu indicators, productive and haematologic parameters, and the levels of these parameters were within their normal ranges during the whole study. There were significant statistic differences in tissue Cu accumulation, mainly in the liver, with 90% of the animals of the Cu supplemented group showing hepatic Cu levels exceeding the adequate range and 50% within the concentrations associated with Cu toxicity. Under the conditions of this study, which are the conditions of the cattle raised under intensive methods in many European countries, routinely Cu supplementation is not justified to maintain an adequate Cu status in the animals or to improve productive parameters. More information about the risk of presence of Cu antagonists in the concentrate diets should be necessary to justify routinely Cu supplementation in intensively reared beef cattle.