Developed in America in the mid-1960’s, these are com varieties possessing the opague-2 gene. The opague-2 gene causes such com to contain 0.30-0.55% lysine (i.e., 50-80% more than traditional No. 2 yellow com). High-lysine com is particularly useful for feeding of swine, since traditional No. 2 yellow com does not contain enough lysine for optimal pig growth.