This mineral is also found in bone but its main role is in the composition of many of the enzymes in the body. Most feed ingredients contain sufficient magnesium and it is not normally necessary to supplement the diet. Reported signs of deficiency include an abnormal gait as a result of lack of enzymes in the nervous system, incoordination and weak knees and hock joints with loss of tendon tension. If calcined magnesite is added to rations in excess diarrhoea may be caused.