I don't think they are supposed to eat nut grass or onion grass either
Hmm must be the botanist in me .... neither of these are grasses. Nutgrass is a sedge, onion grass is a type of lily. But both look grass-like so I am being a bit pedantic! LOL
Mork, you may be ok but blady grass has been linked to toxicity issues in stock so I would personally avoid it. Generally, stock won't eat blady grass -same way piggers won't eat certain foods - but if they have nothing else to eat, then they will.