LOL!! Diane. Yes we do have a little grass!! And I have to let mine out that first day simply because to keep them in off the grass for over 24 hours would/could upset their systems by me having changed their main diet! (not a good idea) As you say, yours are keeping to their normal diet whether they are in or out. The only time I hold off is if it is raining or similar (for the foal's sake), in which case it's mushy food and several half buckets of picked grass several times during the day.