I think timing of vegetable meals is important. If you give a little throughout the entire day, your bun may not eat hay because he knows he’ll get veggies eventually. For Wick, hay is his fall-back food when he gives up with begging in the kitchen. Someone else on these forums used a great example. Veggies are like Snickers, and hay is like a salad. A child isn’t going to eat salad when they’re used to getting Snickers. I do two veggie servings– 1 in the early morning (as a relief from an entire night eating hay), and one in the late evening (as a relief from an entire day eating hay). In between those two feedings, I try not to give into him following me in the kitchen and sitting there, waiting for a veggie-slip or a treat.
If your rabbit is healthy in all other aspects (so no dental issues), if it’s hungry and acknowledges veggies/treats will not come, it will resort to eating hay.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.