The present disclosure is directed to animal feed products and a method of producing animal feed products from lignocellulosic biomass. A lignin swellant is mixed with the lignocellulosic biomass and a grain or starch is added to the biomass mixture. The biomass mixture is introduced to an extruder and heated between about 140° C. and 250° C. The treated material is extruded from the extruder and pelletized.