The vitamin requirements of all animals are well documented through scientific studies carried out under optimal conditions in which minimum requirements are established.
The continuous improvement in our livestock's productivity places ever-increasing demands on a proper, well-balanced intake of vitamins. Warm or cold stalls and good or bad feed are examples of how other factors can affect vitamin requirements. Even the stress to which animals are exposed, for example in connection with environmental changes, transports, feed changes, high production, weaning, and so on, increases their need for vitamins. Normally, the minimum vitamin requirement is well below recommended intake, but requirements under stressful conditions are many times higher than recommended intake.
Adding vitamins to feed is an inexpensive insurance for keeping healthy, happy animals that can maintain high production.