Refers to the practice of loading pre-determined amounts of all feed ingredients and blending them in a mixer, followed by delivery to a group of cows, usually housed and managed in confinement. Typically a dairy nutrition consultant will make recommendations using least-cost ration formulation software to determine the amounts and type of feed to blend based on economic considerations (minimizing feed cost), while providing the lactating cows with all know nutrients required for health and high milk production performance.