Chickens aren't cows. lol
They don't like eating grass any more than you would.

I've been reading a lot about chickens this week at work when I should have been working lol Your best bet is to keep the grass you have and plant some plants that attract bugs for them to hunt down. I just bought Quinoa seeds so I can start a bed of Quinoa. Its an annual herb but if I don't harvest it, it will self sow and the chickens should like the seed heads well enough. I got the parti-colored seed which will have red, yellow and pink feathery seed heads this fall.

Pretty!
Of course, I could be totally wrong but everything I've read so far says chickens don't eat grass. They are not ruminents and have a decided preference for the same things bears would eat. As they are omnivores. Which means they don't have the proper digestive tract for effectively digesting a grass based diet.
Well, I guess I was wrong. MY chickens haven't touched grass for the whole week since I got them. Oh, once or twice they pecked at a seed head in the back lawn but quickly lost interest. They get a constant supply of crumble in their kennel, mealworms for breakfast when the door gets opened for the days start abt. 5 am weekdays and a bit later weekends. They have access to beds of kale, spinach, leaf lettuce and strawberries but don't bother them enough to do any real damage. Just a nibble here and there. Mostly they hunt bugs and sweets and haven't bothered any of my edible flowers. Not even the nasturtiums or pansies. But then I might have lazy chickens. They spend a lot of time rolling around in the bark beds under the flowering shrubs in my back lawn and napping. I guess having 2 chickens less than a month I probably shouldn't believe everything I read and see

Or at the very least I should wait a while before a asume the things I read are true