Milk fever is defined as a sudden drop in blood level of which mineral?

• A. Calcium
• B. Sodium
• C. Potassium
• D. Magnesium

Answer: (A)

Milk fever centers on calcium metabolism. It is a rapid decrease in blood calcium that occurs around calving when a dairy cow’s demand for calcium for milk production spikes far beyond what intake and bone stores can quickly supply. This sudden hypocalcemia impairs muscle function and other calcium-dependent processes, which is what we recognize as milk fever.

Calcium is the mineral involved here, not sodium, potassium, or magnesium. While those electrolytes are important for overall fluid balance and nerve/muscle function, the defining feature of milk fever is the drop in blood calcium. Magnesium deficiency can cause separate issues like grass tetany, and sodium/potassium imbalances aren’t the defining factor for milk fever.