A method of treating livestock animal feed grains by the addition thereto of a sarsasaponin as a wetting agent in conjunction with the mechanical processing to which feed grains are subjected. A preferred sarasasaponin is that extracted from the Yucca plant. Preferably the sarsasaponin is applied from a liquid medium. The sarsasaponin facilitates moisture uptake by the grain, making it more stable, more palatable and more digestible. When fed to livestock, faster weight gains are obtained with less feed. The wetting agent is desirably added to the grain prior to processing by grinding or rolling and steam flaking.