Poultry By-Product Meal is much less expensive and less digestible than Chicken Meal. All of the naturally occurring vitamins have been leeched out by the processing. Ground Rice with its natural nutrients intact would be preferable. Natura does not use Rice Gluten Meal, a poor quality protein filler. Because of this, pet food companies can use the cheaper by-products of human food production, such as Rice Gluten Meal.
Meat is always the best source of quality protein.
Meat protein is better absorbed and retained and is higher in essential amino acids like methionine, arginine, and taurine. This holds the waste in. Kidneys and liver work overtime. Dogs may chew their lower backs. Feet may swell, so the dogs lick their feet.