When you feed your piggies vegetables and occasional fruit you will not believe how happy it makes them! If I shake a bag of lettuce or veggies they go crazy and start popcorning and wheeking.
There are so many choices to let them try. Mine love romaine, green leaf and red leaf lettuce. Also green and red peppers would be a good veggie for them to try, mine love it so much. There is a great link on this site for which veggies and fruits that are safe to eat. I have fun looking thru the veggies section at the grocery store to see what I can try next.
Also, I would not use the vitamin c drops in their water. It makes it taste bad and the vitamins degrade in 15 minutes or so.