Tender little bits of grass are best IMO. But they can eat all kinds of grass. You can run into trouble with long tough grasses. They can get stuck in the crop and cause a stoppage which then ends up in "sour crop". I usually try to pull up the grass, roots and all for my chickens. That way they have a better chance of pulling off bits of grass. But I do give them everything I pull up, even if it is timothy and breaks off at the roots. I have not had that much trouble with long tough grasses. Maybe because they also get a lot of dirt with the roots of at least some of the grass. We also feed a lot of weeds. We just pull what we have and feed it to them.
