DYSREGULATED MICROBIOME, METABOLOME, AND MICROBIOME-METABOLOME INTERACTIONS IN BEEF CATTLE GRAZING TOXIC TALL FESCUE

The impact of Fescue Toxicosis (FT), caused by toxic endophyte-infected fescue grazing, on the US beef industry is enormous. The pathophysiology of FT manifests with physiological, endocrine and metabolic perturbations. We recently showed that these perturbations are associated with changes in the animal's plasma and urine metabolomes, which might be reflective of FT-associated aberrations of the animal's microbiome and/or changes in the fescue plant metabolome/microbiome due to the toxic endophyte's presence. In this project, we will focus on the fescue plant-grazing beef microbiome-metabolome axis within the context of FT. Our overall goal is to use the unique expertise of our interdisciplinary team to obtain fundamentally important, transformative new data on the effects of toxic fescue grazing on the microbiomes and metabolomes of beef cattle and correlate them with key signs of the disease. Our specific objectives are: (i) to characterize the ruminal and fecal microbiomes (bacterial and fungal) of toxic and non-toxic fescue-grazing beef steers; (ii) to characterize the fescue plant's (toxic and non-toxic) microbiomes (bacterial and fungal) and metabolomes to determine their contribution to those of the grazing animal; (iii) identify critical microbial organisms and/or microbial metabolites, either on the plant or the animal side, that are affected in FT or by toxic endophyte's presence in the plant and are amenable to therapeutic manipulations so that they can be explored in the future. Ultimately, the data we generate from this project will guide the implementation of microbiome/metabolome-based management of FT from both animal and plant perspectives.