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Magnesium Deficiency

Other Names: Hypomagnesemia

Magnesium (Mg) is an essential mineral that is required for bone formation, carbohydrate metabolism, and for activation of several enzymes. Severe magnesium deficiency can impede vitamin D and calcium homeostasis; leading to an increased risk of osteoporosis, metabolic disorders, and cardiovascular diseases. In young chicks, deficiencies can cause stunted growth, lethargy, convulsions and death.

Clinical Signs

Poor growth


  • History
  • Clinical Signs
  • Physical exam
  • Diet analysis

Reported Cases

  • Case 1: Magnesium deficiency in a Chickens Calcium absorption was measured by 47Ca disappearance from ligated duodenal loops and 47Ca uptake by tibiae in chicks fed diets containing one of four levels of Mg for two weeks. The diets, otherwise identical, contained 88 (group 1), 150 (group 2), 200 (group 3) and 1000 (group 4) ppm Mg. There were no statistically significant differences in 47Ca absorption. Mucosal CaBP and intestinal alkaline phosphatase were slightly, but not significantly, elevated in the Mg depleted chicks in groups 1 and 2 compared to groups 3 and 4. Microscopic examination of the tibiae showed marked alterations in morphology in chicks fed the 88 ppm Mg diet. The thickness of the epiphyseal plate was reduced, and the morphologic signs of osteolysis and chondrolysis, normally observed in the metaphysis, appeared to be absent. The mid-diaphysis was thickened and showed marked reduction in both osteoblast and osteocytie activity. Blood calcium levels were significantly reduced in the Mg deficient chicks. It was concluded that Mg depletion in chicks altered Ca homeostasis primarily by changing bone structure and function. Ref

  • Case 2: Magnesium deficiency in a Parrot Hypocalcemic-induced seizure activity is a clinical entity that is commonly diagnosed in neurologic African grey parrots. Plasma calcium levels are typically less than 6.0 mg/dL at the time of seizure activity, and although the underlying cause of the hypocalcemia has not yet been determined, many theories have been proposed. An African grey parrot that had been fed a seed diet for 8 years was presented with hypocalcemia and seizures and exhibited precipitously declining plasma calcium levels, despite aggressive calcium and vitamin A, D, and E supplementation for 4 days. Baseline magnesium levels in this parrot were determined to be 1.9 mg/dL; therefore, magnesium sulfate was administered at a dose of 20 mg/kg IM once. Twenty-four hours after supplementation, the plasma magnesium level was 3.3 mg/dL, and no further seizure activity was observed. We believe that a primary dietary magnesium deficiency may have been present in this African grey parrot, similar to a syndrome in leghorn chicks, which is frequently characterized by progressive hypocalcemia that is unable to be corrected by calcium supplementation alone. Ref


Provide magnesium-rich food sources: Magnesium food sources for chickens:



Ensure flock is on a balanced diet and receiving enough Mg

Scientific References

Risk Factors

  • Intake of high amounts of zinc (Zn) interfere with the absorption of magnesium.
  • Large intake of dietary fiber may decrease magnesium utilization
  • Chickens with gastrointestinal or kidney damage