A trace element solution comprises at least the following metals: zinc； manganese； selenium； and copper； and which comprises a concentration of the metals of at least 90 mg/ml. The solution may comprise the following concentrations: at least 60 mg/ml zinc； at least 10 mg/ml manganese； at least 5 mg/ml selenium； and at least 15 mg/ml copper. The solution may comprise chromium, iodine and chromium.
