A study released in August this year in the Journal of Equine Veterinary Science into contaminants in horse feeds has found that “99 % (n = 107) of the samples tested positive for fungal metabolites, particularly Fusarium metabolites, unspecific metabolites, and pesticide residues."
The difficultly with feedbags that have pelletised, micronised or extruded feeds is that you can't see what it actually is. Here are some recent "no grain" alternatives and what they actually contain.