Quantification of zinc concentrations in serum, milk and faeces of dairy cattle as a measure of effective zinc supplementation for management of facial eczema

Comparison of a novel form of zinc with zinc oxide bolus licensed for prevention of facial eczema, and interaction with copper oxide in sheep

“…Positive associations between faecal and serum zinc concentrations have been demonstrated following oral treatment with zinc boluses 10 and following daily drenching with zinc oxide. 11 Using a 2 Â 2 factorial design, it was demonstrated that cows supplemented 3 times weekly with 350 mg of copper sulfate had increased liver copper concentrations compared with untreated controls, that a zinc oxide bolus alone did not depress liver copper concentrations relative to untreated controls, but that liver copper concentrations in cows supplemented with both zinc and copper were lower than in the copper alone supplemented group. 12 Zinc sulfate provided in drinking water depressed plasma copper concentrations in both cows and calves relative to non-supplemented animals.…”

“…No other studies appear to have defined protective cut points for faecal or serum zinc concentrations. Positive associations between faecal and serum zinc concentrations have been demonstrated following oral treatment with zinc boluses 10 and following daily drenching with zinc oxide 11 …”