Comparison of the efficiency of zinc injected as metal or oxide for zinc deficiency treatment in sheep.

Efficiency of zinc injection as metal or oxide suspended in purified oil has been compared with control in three groups of seven ewes (39 kg). The zinc injected as oxide is liberated more rapidly from the injection site and the plasma zinc reachs a higher level than with zinc metal. However the effect of zinc metal injection lasts longer. Plasma copper behaves as an inflammation index. It rises more with zinc oxide injection. Both forms, metal or oxide are well tolerated by sheep without any side effect. Zinc oxide may be injected for more intensive but shorter treatment when zinc metal offers the best delayed effect.