Wheat bran, a by-product of the dry milling of common wheat (Triticum aestivum L.) into flour, is one of the major agro-industrial by-products used in animal feeding. It consists of the outer layers (cuticle, pericarp and seedcoat) combined with small amounts of starchy endosperm of the wheat kernel

Proteins, minerals, oil and fibre are mainly found in the outer layers of the grain and wheat bran is richer in these nutrients than the whole grain. Wheat bran is relatively rich in protein (****9 % DM, sometimes higher) and minerals (**7 % DM), notably calcium (0.***0.2 % DM) and phosphorus (0.**1.3 % DM). Its oil content (**5 % DM) is higher than that of the whole grain. The fibre and starch contents are inversely correlated and extremely variable, as they depend on the relative amounts of envelopes, endosperm and other fractions mixed together. Still, a product marketed as bran should contain relatively high amounts of fibre: crude fibre ***4 DM, NDF ****4 % DM, ADF ***6 % DM and low amounts of ADL **4 % DM. Wheat bran should also contain about ****0 % DM of starch (Feedipedia, ***1). Fibre is the main constraint for the utilization of wheat bran in animal nutrition, particularly in monogastrics. For that reason, the energy values of wheat bran (DE, ME, NE) are always lower than those of the whole grain, in all animal species.