Effect of Mineral Deficiency on the Yield and Composition of Cow's Milk

Abstract

The relation of mineral deficiencies in the ration to the yield of milk is a question of considerable economic importance. It is also important to know from the nutritional standpoint whether the mineral elements of the milk ash--especially calcium and phosphorus--are affected by an insufficient supply of these in the feed consumed by the animal. Jt has long been observed in some of the extremely mineral deficient areas of Europe and Africa that the mill~ yields are reduced markedly when outbreaks of osteomalacia occur. Tuff (1) noted that a decrease in milk yield was a common result of shortage of lime and phosphoric acid in the roughages fed to cows in a part of Norway. If a mineral supplement such as bonemeal or herring meal was fed, the yield of milk was greater. With cows on pasture where osteomalacia did not occur, the milk yield was satisfactory even without such mineral supplements. Theiler (2) observed that ten cows receiving a ration otherwise very deficient in phosphorous produced 40 per cent more milk when the ration was supplemented with bonemeal than did another similar group of cows without bonemeal. Weiske (3) noted that cows decreased in milk flow when receiving a ration low in calcium and phosphorous and Fingerling (4) noted the same results with goats. Hasselbalch (5) divided a large herd of Jersey cows into two groups, one group receiving a commercial mineral mixture. This