Make sure you wash and rinse the veggies multiple times. This is true with spinach (don't feed in large amounts. Spinach can obstruct calcium absorbtion), apricots, and many types of lettuce. IMO, I don't feed iceberg lettuce. Waste of money. If I want my birds to drink water, I'll hand them a dish of water instead of giving them iceberg lettuce. Broccoli seems to mimic fresh green seeds, thus, naturally motivating the birds to eat the veggie. I haven't had much success with any type of fruit. Apples have worked a little, but it's rinse-rinse-rinse because of all the pesticides.

In the beginning, I had a hard time converting them to veggies and fruits. I basically fed them fruits and veggies for breakfast instead of seeds and pellets for a few days. They were 'forced' to eat it, and quickly enjoyed the fresh foods. Now, they fight for vegs and fruits!