ABSTRACT
Asexual Epichloë fungi that form mutualistic endophytic associations with cool-season grasses produce secondary metabolites responsible for anti-quality (toxic) effects on livestock and bio-protective properties that benefit agronomic performance. Globally, toxicity to livestock is of greatest economic importance in large areas of the USA, Australia, New Zealand, Argentina and Uruguay where perennial ryegrass (Lolium perenne) and tall fescue (Festuca arundinacea) are commonly infected with mammalian toxic endophyte strains. Livestock can suffer both clinical and sub-clinical effects, resulting in large losses in productivity, significant effects on animal welfare, and occasionally death. However, endophyte infection is also key for the productivity and persistence of the host grasses. Epichloë strains that are mammalian non-toxic, while retaining the bio-protective properties, can be selected and used in commerce. Food safety studies have found that the low concentrations of secondary metabolites detected in animal fat and milk are highly unlikely to pose a threat to human health.
