Here is a list that in my opinion are good for piggies and which are not. There is alot of conflicting information on this, but this is my advice.
Guinea pigs should be fed daily on a complete food such as pellets or mixed food, a good quality hay and vegetables and fruit. They also occasionally can have readigrass or burgess excel forage. Clean water should always be available.
On a guideance on how much to feed. I feed an example of at least 1 carrot per day or one large cabbage leaf per day or 1 stick of celery per day. But obviously more than one type of veg can be given on one day.
Safe for piggies:
Carrots: You may find many piggies arent that bothered about these, but they do like them occasionally.
Cabbage: This is contraversial. Ours love it and i have never had no problems. Spring cabbage is the favourite.
Curly Kale: again same as cabbage contraversial.
Brocolli: a firm favourite. the stalks are fine too.
The leaves from cauliflower: another favourite
Spinach: as contraversial as cabbage, but a favourite here.
Celery: lots of things about this on the net, my guineas love it and get it often. Never had any problems.
Cucumber: A favourite but not much vitamin value to it. ideal in summer because of the water content.
Herbs: parsley is a favourite.
Dandelions and grass; Ensure nothing has been sprayed on this. A firm favourite and free!!
bananas, kiwis, oranges, pears, tomatoes, melon, corn (baby corn and corn on the cob), root beetroot (not the leaves), purple flowering brocolli, courgettes, green beans,
What guinea pigs cant eat
potatoes- peelings and the potato
Iceberg lettuce- gives very bad stomach problems
Beans- such as kidney beans. (green beans are fine)
Alcohol (should go without saying)
Rabbit, gerbil, hamster, rat food.