Potential Amelioration Of Fescue Toxicosis By 5-Hydroxytryptophan In Beef Cattle

The overall goal of this project is to evaluate the potential of 5-hydroxytryptophan to ameliorate fescue toxicosis in beef cattle and elucidate potential molecular mechanisms. The objectives of this project are to evaluate the potential of 5-hydroxytrytophan to: 1) restore or improve dry matter intake, 2) reduce ergot alkaloid-induced vasoconstriction and susceptibility to heat stress, 3) improve gut integrity and decrease systemic immunoactivation, and 4) affect genes, pathways, and functions of the hypothalamus, lateral saphenous vein, and jejunal mucosa corresponding with objectives 1-3 on feed intake, vasoconstriction, and gut integrity/inflammation, respectively. This project will be evaluated using a multi-faceted approach (nutritional, hormonal, transcriptomic) that will provide novel insights into the onset of fescue toxicosis by ergot alkaloids and amelioration of fescue toxicosis by 5-hydroxytryptophan. This project addresses USDA NIFA AFRI program area priority Animal Nutrition, Growth and Lactation (Program Area Priority Code – A1231) by evaluating the potential of dietary 5-HTP to ameliorate clinical symptoms of fescue toxicosis in beef cattle, a $2 billion issue that decreases the weaning weight of 9 million U.S. beef calves by 50 lbs per animal on average. It is anticipated that 5-hydroxytryptophan will increase serotonin bioavailability in beef cattle consuming ergot alkloids from toxic endophyte-infected tall fescue seed, which will lead to increased vasorelaxation, restored dry matter intake, and decreased immunoactivation. RNA-Seq analysis will provide molecular targets associated with the onset and amelioration of fescue toxicosis.