Optimizing the trace mineral status of pre- and post-weaned beef calves

摘要

Trace minerals are known to be essential for the support and maintenance of immunity in cattle. Beef cattle production systems typically rely on a cow/calf grazing system culminating at weaning when calves are permanently separated from their dams andmoved onto other phases of production, such as backgrounding or feedlot. The trace mineral status of weaned calves is dependent, therefore, on the contribution of milk, forage, and supplement. Unfortunately, warm season forages are commonly deficient inessential trace minerals and milk is a poor source of the two most commonly deficient trace minerals - Cu and Se. This situation, therefore, results in a reliance upon supplements to ensure adequate trace mineral status of calves. During the grazing season, most mineral supplements are blended with salt and formulated to address regionally-specific targeted intakes by the cow. Very little focus is placed on calf intake, which is largely unknown or inadequate. These conditions commonly result in marginal to deficient trace mineral status of weaned calves. Management opportunities aimed at improving the trace mineral status of calves prior to weaning hold merit relative to optimizing post-weaning health and productivity. This article will examine recent efforts to utilize pre-weaning supplements in a limit-fed creep feeding system to improve the mineral status of pre- and post-weaned beef calves.