Oat meal should be fine for bedding them and feeding them... Just like others said it doesn't have much in the way of nutrients so gutload the ones you will be feeding your chams a few days in advance with other veggies.. I've been using a mix of mustard green, dandelion green, Apple, carrot, enchive food processed.. carrots work good also to throw in with your oats because they don't mold easy and can be easily separated and removed if they do