Zinc is an essential micronutrient in cattle diets. Clinical signs and abnormalities present in cattle with zinc deficiency include decreased growth rate, diarrhea, poor appetite, salivation, abnormal hooves, swollen joints and coronary bands, stiff gait, hair loss, parakeratosis, thymic atrophy, lymphoid depletion, decreased disease resistance with specific depression of cell-mediated responses, and decreased reproductive performance. These clinical signs are not
pathognomonic and zinc deficiency could readily be overlooked. Although experimental zinc deficiency readily induces clinical disease, the diagnosis of zinc deficiency is rarely made by veterinarians.
Cattle have a small, labile zinc storage pool. Clinical signs and laboratory abnormalities associated with zinc deficiency occur rapidly after removal of zinc from diets and rapidly return to normal after supplementation. Consequently, optimal zinc nutrition requires ongoing, adequate, and continuous intakes. Zinc deficiency can be induced either by low dietary zinc concentrations or excess dietary calcium, sulfates, iron, or molybdenum.
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