PureBites freeze-dried liver treats are only made with one ingredient -- 100% pure USDA-inspected duck liver in the USA. Dogs love the taste of PureBites, which uses a delicate freeze-drying process to remove only the water of fresh, whole food, preserving all the characteristics and nutrition of fresh duck liver. These average about 3 calories per piece. They are easily broken into small pieces, which is why we use them so much for training. No corn, no soy, no grains.