Do you know what they've been scoffing before you got them? Off the top of my head (thinking what's in season and a favourite of my boys)
Sweetcorn (on the cob) Carrot Cucumber Celery (ours love the leaves) Rocket Salad bags (but NO iceberg) Peppers (mine like red/yellow/orange ) Romaine Apple- tiny bits Bananas PARSLEY -GP1 favourite Cauliflower stems (I give mine the white bit buy only a tiny bit) Pasnip peelings Turnip
Careful with cabbage, brocilli, greens- can give them wind.
When strawberries, grapes, melon are in season they love them
Offer them little bits. I give 3-4 choices for supper, different 3-4 for breakfast. And if you can , fresh cut grass and dandelions.
There are loads of lists on threads here. There are some definate NOs:
iceberg lettuce (too watery) potato (any part) beetroot leaves (the actual beetroot is fine but not in season) Anything with a stone (peach, plums, cherry) Lots of weeds they can't have,
Careful with herbs, mine go arsey with coriander. They love parsley but only as a treat.
And: anything you wouldn't eat yourself , you don't give the guineas.