Mitigation of Fescue Toxicosis with Soybeans

Project Summary: The objectives of this proposal are to determine: 1) The effects of soybean co-products on mitigation of ergot alkaloid induced vasoconstriction in beef cattle 2) The effects of soybean co-products on susceptibility to heat stress 3) The effects of soybean co-products on decreasing systemic immune system activation 4) Economic evaluation of soybean co-product inclusion in beef cattle diets as a strategy to mitigate fescue toxicosis Benefit to Soybean Growers: Fescue toxicosis, caused by the consumption of ergot alkaloids from toxic endophyte-injected tall fescue, decreases the weaning weight of over 9 million beef calves in the Southeastern United States every year. This decrease in productivity translates to a $2 billion loss in economic revenue for the beef industry annually. There are few solutions that are both economically feasible and effective in treating fescue toxicosis. Recent research demonstrated that bioactive compounds from soybean meal mitigated ergot alkaloid vasoconstriction in goats. If this was demonstrated in beef cattle, it would increase demand for soybean or soy co-product supplements in beef diets. While soy products are common in swine and poultry livestock diets, the beef industry accounts for only 6.8% of soybean meal use. If all calves consuming fescue were supplemented with 1.5 lbs/d of a soy co- product to prevent fescue toxicosis, it would result in an extra 13.5 million lbs/d of soy co-products fed to cattle. Economic Impact: Beef cattle consuming tall fescue are typically supplemented with corn, distillers grains, or blends of co-products. However, other supplements do not contain the same bioactive compounds, such as isoflavones and essential amino acids, that are found in soy co-products. The low usage (6.8%) of soy co-products by the beef industry presents a huge opportunity to increase soybean utilization in beef cattle diets. The bioactive compounds in soy co-products are ideal to mitigate symptoms of fescue toxicosis and thus, could present a new market for soybean farmers to sell their products. We estimate that cattle consuming fescue (15 lb/d) would consume approximately 10% as soy co- products (1.5 lb/d). If 9 million beef calves consuming tall fescue were supplemented with 1.5 lb/d of soy co-products, it could potentially increase soy co-product usage in beef diets by 13.5 million pounds per day. For soybean meal (assuming $350/ton cost), this would result in an additional $2.3 million dollars in soybean meal sales per day to the beef industry. Economic Analysis: In the proposal, we will calculate the economic cost of feeding soybeans in beef diets to reduce fescue toxicosis vs. no supplementation. It is expected that cattle supplemented with soy co- products will have greater weight gain and thus, provide a positive return on investment for beef producers. At the same time, it will also be calculated how inclusion of 1.5 lb/d of whole soybeans, soybean meal, or soybean hulls would impact sales of soy co-products to the beef industry.