Minimizing costs of feeding and prevention of diseases in cattle herds can determine the success of beef cattle production. Therefore, two studies were undertanken to determine whether copper deficiency increases the susceptibility to acquire pink eye, a common and highly-infectious disease in cattle herds; and to investigate the use of Johnsongrass (Sorghum halepense) as an alternative ensiled forage. In experiment 1, copper deficiency was experimentally created over 94 days and animals were challenged with Moraxella bovis at the end of feeding period. In experiment 2, Johnsongrass was harvested at four maturity stages (3 weeks, boot, flower, and dough) to evaluate the effects on yield and quality. Our findings suggest that copper status plays a role on activation of the imune response. In addition, it was demonstrated that Johnsongrass can be ensiled, but quantity and quality is balanced by harvesting Johnsongrass before the flower stage.