Goal/Objective: To determine the effect of supplementation with varying levels of TM (including but not limited to Cu, Mn, and Zn) on the feed efficiency, average daily gain, and clinical health of beef cattle during the receiving and finishing phases of production.In beef cattle production, there is a continuing need to increase animal performance and improve animal health. While supplementation of TM is not a new management practice, it is becoming increasingly common to include selective TM such as Cu, Mn, and Zn in feedlot diets at levels that exceed published nutrient requirements (Samuelson et al., 2016). It has been well established that certain TM is essential for overall performance and immune function. In addition to general health and immune function mechanisms, supplementation of TM has been demonstrated to alter specific immune function measurements and reduce morbidity associated with BRD in some cases (Galyean et al., 1999). Supplementation of TM, including Cu, Mn, and Zn, has been a longstanding management practice within the feedlot industry to avoid unwanted deficiencies and to promote maximum animal performance. In addition, there is some evidence suggesting these TM play an important role in the clinical health and immune function of calves. However, the published research concerning the supplementation of Cu, Mn, or Zn at levels greater than published requirements has produced inconsistent results to date. Research on the effects of varying concentrations of TM during the receiving and finishing periods is needed to quantify whether supplementing TM in excess of published requirements can impact feed efficiency, average daily gain, and clinical health of beef cattle. The results of this research could allow beef producers to improve production efficiency and positively impact animal health. If the improved performance of calves and benefits to clinical health is realized during the receiving or finishing phases, as a result of elevated TM supplementation, this could result in healthier calves and overall improvements in the production efficiency and improved economic and environmental sustainability of beef.Hypothesis: We hypothesize that feeding elevated levels of TM, including Cu, Mn, and Zn, during the receiving and finishing phases will positively impact the clinical health and improve the performance of stressed calves.OBJECTIVES: The objective is to determine the effect of supplementing elevated levels of TM (Cu, Mn, and Zn) on the feed efficiency, average daily gain, and clinical health of beef cattle during the receiving and finishing phases of production.