Abstract: A method and apparatus whereby livestock and poultry are administered feed additives in their feed ration. In one disclosed form, the apparatus stores additive concentrates separately until just prior to use, then on demand dispenses the additive concentrates separately and sequentially into a weigh hopper for sequential, cumulative weighing therein. The weighed contents of the weigh hopper are deposited into a liquid carrier within a mixing vessel where the dispensed additives are diluted, suspended, and dispersed by mixing. The resulting carrier-and-additive slurry is pumped to a receiving station for mixing with a feed ration. The weigh hopper is isolated from movements that would affect additive weight determinations during the weighing process so that accurate measurements of the additive weights are obtained. A computerized control system controls the operation and sequencing of the apparatus.