Hypocalcaemia in dairy cows, is a metabolic disorder that occurs when the cow’s blood calcium levels drop below normal, typically during the transition period around calving. Calcium is essential for various physiological functions, particularly muscle contraction, nerve transmission, and milk production. The demand for calcium increases significantly during early lactation as the cow produces milk, but if dietary intake or mobilisation from bone stores cannot meet this demand, hypocalcaemia develops.
Milk fever primarily affects older cows or those with high milk production. Symptoms of hypocalcaemia include muscle weakness, recumbency (inability to stand), reduced appetite, and in severe cases, death. Blood calcium levels below 2.0 mmol/L (8.0 mg/dL) are typically indicative of hypocalcaemia.
The primary cause of hypocalcaemia is an inability to mobilize enough calcium from the cow’s bone reserves to meet lactational needs, compounded by dietary imbalances, particularly low calcium or high potassium diets, which hinder calcium absorption. Preventative strategies include dietary management, such as implementing negative DCAD diet in the dry period to enhance calcium mobilization, along with the use of oral or intravenous calcium supplements during treatment. Monitoring blood calcium levels and maintaining proper mineral balance during the dry period can help mitigate the risk of hypocalcaemia and its associated complications, such as ketosis and retained placenta.
