I’ve been using an alternating schedule of carrots and organic dandelion greens as my base. I’ll add a little dry dog food now and then (maybe once a month or two). Endives are good and so is kale and sweet potatoes; occasional apples and pears are ok but they rot fast and are mostly sugar anyway. Avoid potatoes as they are not very nutritious. Ultimately a varied diet is good as you want to transfer a variety of nutrients to your animals. Use a good supplement such as repashy supercal to dust your feeders and you’re good. I wouldn’t rely on Petco gutloading their feeders. It’s best to gutload on your own for 48 hours prior to feeding.