Milk Fever in Dairy Cattle: Welfare and Prevention

Milk fever, or hypocalcaemia, is one of the most common metabolic diseases at calving in dairy cows, causing acute suffering and increasing risk of other serious conditions.

Key Facts

Milk fever occurs when blood calcium drops sharply at calving as cows begin milk production, depleting calcium faster than it can be mobilised.
Clinical milk fever causes progressive muscle weakness, inability to rise, depression, and if untreated, coma and death.
Subclinical hypocalcaemia (no visible symptoms) is estimated to affect 25-50% of multiparous dairy cows at calving.
Even subclinical hypocalcaemia increases risk of retained placenta, displaced abomasum, mastitis, and metritis.
High-producing modern dairy breeds are most susceptible; Holstein-Friesian cows have higher rates than Jersey cows.
Prevention through dietary management in the dry period — particularly reducing dietary calcium — is highly effective.
Oral calcium supplementation at calving is widely used and reduces both clinical and subclinical hypocalcaemia rates.
Intravenous calcium treatment of clinical cases provides rapid recovery but requires veterinary or farmer training.

Welfare Considerations

Milk fever illustrates the welfare cost of selecting dairy cattle for extreme milk production without equal attention to metabolic robustness. Clinical milk fever is genuinely frightening and painful for affected cows: progressive paralysis, inability to rise, and distress as the condition worsens. Even subclinical hypocalcaemia — the invisible majority of cases — causes significant physiological stress and opens the door to a cascade of secondary diseases. Prevention is highly effective and cost-beneficial, yet prevalence remains high because implementation requires consistent dry-period management that not all farms achieve. A welfare-centred approach to dairy management would make hypocalcaemia prevention a standard, monitored protocol.

What You Can Do

Support dairy welfare standards that require monitoring of fresh cow disease rates including milk fever.
Advocate for routine blood calcium testing of fresh cows as a herd health management standard.
Choose dairy products from farms demonstrating low transition disease rates as welfare indicators.
Encourage dairy vets and nutritionists to prioritise dry-cow mineral management as a welfare priority.
Support research into alternative approaches to hypocalcaemia prevention that reduce reliance on individual cow treatment.