feeding your chickens hay?

I have a flock of 20 hens and one roster in a chicken house and yard that really isn't built for that many to stay in 24/7. They free range three days a week, I had to work out a schedual with the neiboor so his dog dosnt kill more of my chickens. The hens range in age from over a year to about 2 1/2 months. I have been collecting grass clippings for them occasionally as well as veg. and fruit scraps. They have free choise layer feed and pister shells and a few handfulls of scratch each morning. The other day I got a bale of very nice first cutting hay which I am using to bed the nest boxes. I chose this over straw because I know they like to eat it. Is it odd or a bsd idea to feed them hay on the days they are shut up in the run and house and cant get out to forage? They love it and offers a distraction for them. Any opinions?

Hay is fine in the boxes, and they do like to play in it and eat the seeds and tender leaves. Mary

I would not be giving them grass hay but I do give dairy quality alfalfa, cereal grain hays (oat, millet or triticale) or oat/pea as a winter staple. I'll put out the entire bale so it's just as much a toy than a food source.

My hens used to roam the hay barn when they were free range and probably ate a lot of grass hay. If they free range they probably get enough grit, that would be the only concern.

Good quality horse hay is the best I can get my hands on. I can get some alfalfa every once in a while. And I make sure they have ground oister shells to pick at as well as being able to pick up what they want when they run free. My biggest concern is that it will be bad for their health. But I wanted to give thwm something to pick at on the days they are shut up.
Thanks to everyone so far for the info and suggestions.

I give mine a little oat hay every day. The can't free range. This gives them something to scratch in - just like a real chicken! They always have access to grit, which will help them digest it. My endurance horse foundered last year & can't eat oat hay any more so I've got to get rid of it.

My horses eat grass hay, and the chickens root around in it daily. No problem! There's nothing about grass hay that's a problem. Mary

chickens eat grass and other greens constantly while free ranging,,, just pen some in a smaller area for a while and see how fast it gets defoliated if you have any doupt. hay is no different,, although they tend to go for the leaves and finer stems and leave the thicker stems lay,, just make sure they are still getting a well balanced diet of grain and you are not expecting them to survive on just hay. during the summer a save my lawn clippings and dry them for use in the winter to give my girls a green treat when the snow is well over their heads,, they love it and will cluck around happily scratching and digging to get the choicest green before the others. greens and such will also keep your yolks darker colored thru the entire winter and they won't get that pale washed out yellow color.

On a side note,, I don't recomend using it in nest boxes,, being that chickens like green stuff to eat,, and scratching and digging is a thing chickens do while eating,, any eggs in the nest may becomes smashed or deposited on the ground and eaten