Grains are high in feed nutrients, low in fiber, and a good source of phos- phorus. As production increases, grain is needed to meet nutrient needs. Examples are soybean and linseed meal. At high levels of milk production, cows need much protein in their ration. A guide for topdressing is 1 lb of protein supplement per 10 lb of milk over 50 lb.
Mineral supplements are feeds that contain key minerals needed by the cow.
Di-calcium phosphate and trace mineralized salt are examples. Topdressing 2 to 4 ounces per cow per day is another method of feeding. Vitamins are found in feeds or synthetic products. A are examples. Dairy cows need vitamins A and D which can be provided by forage and grains, supplemented with a vitamin premix, or injected.