The value of corn as a feed grain depends on the yield per acre, the protein content of the grain, and for some livestock, the lysine level of the protein. Most farmers are aware of yield differences among hybrid corn varieties but may not realize that protein content can also vary significantly. Grain protein level should be accounted for to determine how much protein supplementation will be needed to balance an appropriate animal diet. However, since corn protein is deficient in the amino acid lysine, which is essential for non-ruminant animals, lysine content as well as crude protein content should be considered in diet formulations for these animals.
Hu, Z.; Poneleit, C. G.; Evans, K. O.; Collins, Michael; and Liptrap, D. O., "Hybrid Variation for Yield, Crude Protein, and Feed Value of Corn" (1991). Agronomy Notes. 51.