Natural feed additives may be obtained as byproducts of manufacturing, and their use in animal production can minimize environmental damage associated with waste disposal. The ALCELLR process for manufacturing papermaking pulps yields pure lignin, a co-product that appears to have application in animal feeding and nutrition. The addition of lignin (1.25 to 5% ) to the diet of pigs and calves has been shown to improve growth performance and reduce the incidence of diarrhea. There are also reports that addition of purified lignin to the diets leads to alterations in VFA patterns and bacterial populations in the hindgut.[...