A process for improving the utilization of feedstuffs by a ruminant, the process comprising the steps of mixing a lactic acid producing bacteria culture and a lactate utilizing bacteria culture, admixing these cultures with a dry formulation or an animal feedlot diet into a composition, and administering this composition orally to ruminants. The process may be used on a continual basis to increase meat or milk production, or used during the transition from a roughage diet to a feedlot diet to prevent or minimize acidosis. The preferred embodiment utilizes Lactobacillus acidophilus as its lactic acid producing bacteria culture and Propionibacterium P-5 as its lactate utilizing bacteria culture. The composition of the process is in a dry powder form for storage at ambient temperatures for long durations.