High sulfur related thiamine deficiency in cattle: A field study.

Following development of polioencephalomalacia in one of 105 cattle in a farm in southeastern Saskatchewan, a study was initiated to monitor thiamine (B(1)) and copper (Cu) status, and to evaluate interactive nutritional factors which may have been responsible for this occurrence. It was evident that a combination of high sulfur (S) and low Cu intake was responsible for the depletion of blood B(1) and plasma Cu. Supplementation with trace minerals alone resulted in a significant (p<0.05) improvement in both B(1) and Cu status of the herd. We recommend that herds exposed to high intakes of S be supplemented with Cu up to 50 mg/kg feed dry matter to alleviate potential deficiencies of B(1) and Cu.