Wheat middlings and red dog are coproducts of the wheat milling process that are used as a source of energy and protein in animal feed. Wheat middlings are granular particles of the wheat endosperm, bran and germ. Red dog consists mainly of the aleurone layer that lies between the bran and the endosperm, along with small particles of bran, germ, and flour. It is often used in extrusion mixtures and as a pellet binder.
The digestibility of crude protein and amino acids in wheat coproducts produced in China has been reported, but there is limited information about the nutritional value of wheat middlings and red dog produced in the United States. In addition, because wheat coproducts vary in terms of the conditions under which they are produced, their nutritional value may vary as well. Therefore, the objective of this experiment was to determine the concentration and digestibility of crude protein and amino acids in ten sources of wheat middlings and in one source of red dog.
