Further investigation of equine fescue oedema induced by Mediterranean tall fescue (Lolium arundinaceum) infected with selected fungal endophytes (Epichloë coenophiala)

Toxigenic Endophyte-Infected Tall Fescue and Ergot Alkaloids

"Fescue toxicosis" and reproductive ergotism present identical toxidromes in late-gestational mares and, likely, other equids. Both toxic syndromes are caused by ergopeptine alkaloids (EPAs) of fungal origin, and they are collectively referred to as equine ergopeptine alkaloid toxicosis (EEPAT). EPAs are produced by either a toxigenic endophyte (Epichloë coenophiala) in tall fescue and/or a nonendophytic fungus (Claviceps purpurea), infecting small grains and grasses. EEPAT can cause hypoprolactinemia-induced agalactia/dysgalactia, prolonged gestation, dystocia, and other reproductive abnormalities in mares, as well as failure of passive transfer in their frequently dysmature/overmature/postmature foals. Prevention relies on eliminating exposures and/or reversing hypoprolactinemia.

Epichloë Fungal Endophytes-From a Biological Curiosity in Wild Grasses to an Essential Component of Resilient High Performing Ryegrass and Fescue Pastures

The relationship between Epichloë endophytes found in a wide range of temperate grasses spans the continuum from antagonistic to mutualistic. The diversity of asexual mutualistic types can be characterised by the types of alkaloids they produce in planta. Some of these are responsible for detrimental health and welfare issues of ruminants when consumed, while others protect the host plant from insect pests and pathogens. In many temperate regions they are an essential component of high producing resilient tall fescue and ryegrass swards. This obligate mutualism between fungus and host is a seed-borne technology that has resulted in several commercial products being used with high uptake rates by end-user farmers, particularly in New Zealand and to a lesser extent Australia and USA. However, this has not happened by chance. It has been reliant on multi-disciplinary research teams undertaking excellent science to understand the taxonomic relationships of these endophytes, their life cycle, symbiosis regulation at both the cellular and molecular level, and the impact of secondary metabolites, including an understanding of their mammalian toxicity and bioactivity against insects and pathogens. Additionally, agronomic trials and seed biology studies of these microbes have all contributed to the delivery of robust and efficacious products. The supply chain from science, through seed companies and retailers to the end-user farmer needs to be well resourced providing convincing information on the efficacy and ensuring effective quality control to result in a strong uptake of these Epichloë endophyte technologies in pastoral agriculture.