Wheat middlings are a byproduct of flour milling, made up of the smaller particles left over after white flour is extracted from the wheat kernel. Sometimes called “wheat midds,” they contain a mix of bran fragments, germ, the aleurone layer (the protein-rich outer lining of the endosperm), and small amounts of flour. They’re one of the most widely used feed ingredients in livestock nutrition and are increasingly showing up in human food products as well.
How Wheat Middlings Are Made
When wheat is milled into white flour, the kernel goes through a series of grinding and sifting steps. After each grind, the crushed material passes over a set of sloping sieves that sort it into three categories: coarse fragments (which get ground again until only bran remains), fine particles that pass through the smallest sieve (this becomes flour), and intermediate granular particles that fall somewhere in between. Those intermediate particles are the middlings.
The middlings then go through additional sifting and air separation, called purifying, to remove light bran flakes. What remains is a fine, tan-colored powder that’s denser in protein, fat, fiber, and minerals than white flour, because the nutrient-rich outer layers of the kernel are concentrated in it rather than stripped away.
Nutritional Profile
Wheat middlings pack considerably more nutrition than the refined flour they’re separated from. Across multiple laboratory analyses, the average crude protein content runs about 17.7%, roughly double that of corn. They contain around 20% starch, 1.17% phosphorus, and a total dietary fiber content averaging 36.5%. The mineral (ash) content sits at about 5.8%.
That high fiber and protein combination makes middlings especially useful as a feed ingredient, but it also limits their energy density compared to grains like corn. On a total digestible nutrient (TDN) basis, middlings provide about 70% TDN versus corn’s 90%. The tradeoff is that middlings deliver substantially more protein and fiber per pound, which can reduce the need for separate protein supplements in a feed ration.
How They Differ From Bran, Shorts, and Red Dog
Flour mills produce several byproducts that sound similar but differ in fiber content and particle makeup. The Association of American Feed Control Officials (AAFCO) draws the lines based on crude fiber limits:
- Wheat bran: the coarsest byproduct, consisting of the large outer husk pieces.
- Wheat middlings: finer particles of bran, germ, flour, and tail-of-the-mill material, capped at 11% crude fiber.
- Wheat millrun: a similar blend capped at 9.5% crude fiber.
- Wheat shorts: mostly fine bran and germ with small amounts of red dog, capped at 7% crude fiber.
- Red dog: primarily aleurone layer material with traces of bran, germ, and flour, capped at 4% crude fiber.
In practice, the lower the fiber cap, the closer the product is to flour in texture and energy content. Middlings sit on the higher-fiber end, making them bulkier but also richer in the nutrients found in the kernel’s outer layers.
Use in Animal Feed
About 90% of all wheat milling byproducts, middlings included, go into livestock feed. Feed manufacturers often include wheat midds in commercial feeds and supplements because of their favorable protein-to-cost ratio. When corn is priced at $2.50 per bushel, the relative value of wheat middlings works out to roughly $72.57 per ton based on energy alone. Add credit for the extra protein (18% versus corn’s 9.8%), and that value rises to about $109 per ton, making middlings competitive with corn in many feeding scenarios.
Middlings are fed to cattle, pigs, and poultry. In pelleted feeds, they also serve a practical role: pelleting roughly doubles their bulk density to about 40 pounds per cubic foot, which makes storage and handling easier.
Mycotoxin Concerns
Because wheat middlings concentrate the outer layers of the kernel, they can also concentrate mycotoxins, particularly deoxynivalenol (DON), commonly called vomitoxin. This toxin is produced by Fusarium molds that thrive in cool, wet growing conditions. The FDA sets advisory limits for DON in grain byproducts used in feed: 10 parts per million (ppm) for beef cattle and chickens, and 5 ppm for swine and most other animals. Pigs are the most sensitive species, and grain byproducts should not exceed 20% of a pig’s total diet when DON is present. Testing middlings before feeding, especially after wet harvest seasons, is standard practice for producers managing mycotoxin risk.
Use in Human Food
While animal feed dominates, roughly 10% of global wheat milling byproducts are used in human food, and that share is growing. Middlings appear most often in the bakery and cereals sector: breakfast cereals, bread, cereal bars, and rolls. Their high insoluble fiber content makes them useful as a functional ingredient for boosting the fiber content of processed foods, and researchers are actively evaluating specific wheat cultivars whose middlings are best suited for use as dietary fiber supplements. Global production of wheat milling byproducts exceeds 150 million tons annually, so even a small percentage shift toward human food applications represents a significant volume.