Daffodils are toxic but chickens aren't likely to eat them. The leaves are thick and tough. They might try to take a nibble of the bright blossoms when they're in flower, so if you grow them, try to keep your chickens away when they're in flower.
I don't know what USDA zone you're in, so it's tough to know what to recommend planting. Also, I have no experience with prairie dogs. But rabbits and chickens will generally avoid eating anything with a strong smell, and that is mostly herbs. Thyme, lavender, rue, bean herb, hyssop, sage, artemisias. Rosemary is very good if you can grow it in your area. Euphorbias are good. Hardy geraniums. Catmint isn't toxic to chickens, and that is a good one. Probably agastaches. Maybe marigolds and chrysanthemums and feverfew. Alliums, including chives and Chinese chives. All are worth trying.
With rabbits, I find that putting a wire cage over the tender new growth works well. Once the plants are bigger and have tougher stems and leaves, rabbits will usually leave them alone, and they can usually make good any damage that's done at that point, anyway.