I have found a happy medium! I have a large run round the chicken shed that they are in when it is wet or bad weather, they get out into the garden for a few hours every day provided it isn't chucking it down like today. So they haven't trashed my garden. I didn't bother with the more expensive and in my view wasteful crumbs. I gave mine some ground down pellets in with the whole ones and they adapted straight away. I also gave them my now famous porridge breakfasts - rolled oats, boiling water over them, honey, citricidal, cooled with milk and served - they love it