Failure of oral zinc supplementation to control ovine foot rot

The efficacy of oral zinc supplementation on ovine foot rot was studied. Th e severity of foot rot lesions in animals receiving 2g SO4Zn 7H(2)O twice w eekly during 4 months was not different from control animals receiving no z inc supplementation. Serum zinc levels were not influenced by zinc treatmen t. Serum zinc concentrations were within normal range (greater than 12.2 mu mol/l) in treated and control group ewes at the beginning of the trial and remained so throughout the experiment. It is concluded that the therapeuti c effect of zinc on foot rot may be related to a pre-existing condition of zinc deficiency and that animal with normal zinc levels are non-responsive to zinc supplementation. (C) 1999 Elsevier Science B.V. All rights reserved .