Improved particulate feed additives and methods are provided for enhancing feed utilization efficiency in a ruminant animal by adding to the feed of the animals a particulate feed additive comprising a nonionic surfactant to enhance the utilization of the feed by the animal and a sufficient amount of an antioxidant agent to substantially enhance the shelf life of the feed additive. The methods and compositions result in enhanced weight gain and/or milk production by the animal.
