Hypomagnesaemia was reported as a common clinical problem in calves in Egypt.  The present study was conducted to diagnose hypomagnesemia in calves and evaluate the treatment of diseased cases by using Mg oxide, Basil &Thyme as food additives. Currently, a total of 1000 female Holstein dairy calves imported from Europe to the farm of the Faculty of Agriculture- Sakha- Agriculture of Research Institute aged 7-9 months, out of these calves 450 have nervous manifestations suspected hypomagnesemia and confirmed by detection of serum magnesium. After symptomatic treatment of diseased cases, calves were separated and divided into 4 groups each one containing 50 calves; the apparently healthy group (control) fed on a balanced ration according to NRC, diseased calves fed on a ration with a high protein diet, treated calves fed on a balanced ration with the addition of Mg oxide 10gm/animal/day for 2 months and treated calves fed on balanced ration with the addition of Basil and Thyme 2% (2 kg/100 kg ration) for 2 months. According to the findings, there was a significant decrease in sodium, phosphorus, magnesium, ionized magnesium, calcium, ionized calcium, GSH, SOD, TAC, glucose, insulin, cortisol, and PTH levels while, there was an increase in potassium, liver, and kidney enzymes, CPK, T₄, in diseased group comparing with the control one. Treating diseased animals with magnesium oxide or Basil and Thyme revealed improvement of minerals, antioxidants, glucose, insulin, cortisol, PTH levels, and a decrease in liver & kidney enzymes, T4, MDA, & CPK levels within normal range.