Milk fever in cattle is most commonly associated with which metabolic abnormality?

• A. Within 24 hours postpartum
• B. Within 3 days postpartum
• C. Within 1 week postpartum
• D. At any time during lactation

Answer: (A)

Milk fever is parturient hypocalcemia — a drop in blood calcium that happens when the cow rapidly loses calcium into colostrum and milk at calving. The demand for calcium is highest right after birth, and the body's ability to mobilize calcium from bone and absorb it from the gut often doesn’t keep up quickly enough. Because of this, signs of milk fever most commonly appear within 24 hours after calving. While cases can occur later, the first-day postpartum window is the classic course, making it the best answer.