These are diseases of livestock caused by productivity practices when the body reserves on calcium, magnesium or energy cannot meet the metabolic needs. They are very important in places where high producing animals are required, e.g. in diary industry. In cattle, metabolic diseases include ketosis, milk fever, fat cow syndrome, and hypomagnesaemia. All these can produce an acute, temporary, but potentially fatal deficiency. Correcting the diet for cows during the period from late pregnancy to peak lactation is crucial in preventing these diseases. If these diseases occur frequently, it is essential to seek professional veterinary and nutritional advice.