Trace Minerals for California Beef Cattle 

University of California, Cooperative Extension

Zinc

    Zinc (Zn) is an essential trace mineral for cattle. Only small amounts are stored in the body so diets that are deficient in Zn will rapidly lead to deficiency. Inadequate Zn results in reduced weight gains, slower wound healing, increased foot problems and impaired reproduction in bulls and cows. Other signs of deficiency may include listlessness, itching (especially on the neck, head and legs), vision impairment and excessive salivation. Some feeding trials have also reported improved udder health and carcass characteristics. Deficiencies are difficult to detect in early stages or milder forms.

Generally, serum Zn levels should be 0.8 to 1.4 ppm. Suggested dietary Zn levels are 9 - 18 mg./lb. of diet dry matter.  Liver zinc levels of 25-100 ppm wet weight basis are generally considered adequate, with levels below 35 ppm wet weight basis deficient.

Excessive supplements with Zn have been found to lower copper (Cu) status. Thus, whenever Zn is supplemented, Cu status should be monitored. If Cu levels are marginal before Zn supplementation, it is possible that Cu will become limiting, leading to a need to supplement Cu.

Excess Zn can be harmful. Care must be taken to avoid excess Zn consumption by cattle or other animals.