Soybean Products as Protein Sources in Feeds for Broiler Chickens and Turkeys This subject was reviewed for broiler chickens by Penz and Brugali (2000). The primary type of SBM used in broiler chicken diets is dehulled, solvent-extracted SBM, which contains ~48% protein. The lower protein SBM with the hulls, containing 44–45% protein, can also be used; however, growth performance, particularly feed efficiency, will be better for chicks fed dehulled SBM (Penz & Brugali, 2000). Full-fat soybeans, either toasted or extruded, are also an excellent protein source for broilers. The inclusion rates of full-fat soybeans may depend on the physical form in which they are fed. When high amounts of full-fat soybeans are fed, the diets may need to be pelleted to improve diet density or breakdown of plant cells to better release nutrients (Waldroup & Cotton, 1974); these latter researchers concluded that most diets should not contain >25% of full-fat soybeans. It is possible that greater concentrations may be used in pelleted diets; however, other studies indicated that full-fat soybeans can replace up to 100% of the SBM in broiler diets (Penz & Brugali, 2000). The principles for using SBM in turkey diets are similar to those for broiler chickens, but SBM is often used at higher concentrations in diets fed to young turkeys due to their higher AA requirement compared with broiler chickens.