Mineral Supplements and Feed Additives--Can They Eliminate Fescue Toxicity?

Fescue is the predominate cool season grass in much of the United States due to its wide adaptation and hardiness. Many of these acres however, contain an endophytic fungus resulting in production of toxins with negative effects on grazing cattle. The two primary responses in beef cattle are an increase in core body temperature and a decrease in dry matter intake. As a result, decreases in reproductive rates, milk production, weaning weights and ADG are seen (Tables 1 and 2). Many approaches to pasture management have been advocated to overcome or minimize the problem such as incorporation of legumes, rotational grazing, establishment of endophyte free stands or use of friendly endophyte varieties of fescue. While all of these can be beneficial, substantial investment and time is required and success is not guaranteed. Direct application of a compound or product to the animal that alleviates symptoms is the method most preferred by producers. Supplementation of several products have been advocated in recent times to assist in overcoming fescue toxicity. Each will be examined in this paper