Metabolic Disease in Dairy Cows: Welfare Management

Metabolic Disease and Dairy Welfare

The periparturient period — the weeks around calving — is the highest-risk period for metabolic disease in dairy cows. Hypocalcaemia (milk fever), ketosis (acetonaemia), and grass staggers (hypomagnesaemia) cause significant welfare harm and are largely preventable with appropriate management.

Hypocalcaemia (Milk Fever)

• Cause: Sudden demand for calcium in colostrum and milk at calving exceeds mobilisation capacity, particularly in high-yielding cows and older cows.
• Welfare impact: Subclinical hypocalcaemia causes muscle weakness, impaired immune function, and predisposes to other diseases. Clinical cases cause recumbency, inability to rise, and risk of secondary complications.
• Treatment: IV or subcutaneous calcium borogluconate; prompt treatment is essential — recumbent cows deteriorate rapidly.
• Prevention: DCAB diet (dietary cation-anion balance), oral calcium supplementation at calving, vitamin D management.

Ketosis (Acetonaemia)

• Cause: Negative energy balance in early lactation; fat mobilisation produces ketone bodies that accumulate when not adequately metabolised.
• Welfare impact: Subclinical ketosis (high blood ketones without clinical signs) impairs immune function, fertility, and milk production. Clinical ketosis causes anorexia, depression, weight loss, and CNS signs (nervous ketosis).
• Monitoring: Cowside ketone testing (blood BHB) from days 3-14 post-calving identifies subclinical cases for early treatment.
• Treatment: Propylene glycol oral drench; IV glucose for severe cases; treat concurrent diseases.
• Prevention: Maintaining appropriate dry cow body condition (BCS 3.0-3.25); optimising dry matter intake transition period.

Hypomagnesaemia (Grass Staggers)

• Cause: Inadequate magnesium absorption from lush spring or autumn grass; magnesium cannot be mobilised from body reserves.
• Welfare impact: Sudden onset neurological signs — excitability, muscle tremors, tetany, convulsions, and rapid death. A welfare emergency.
• Treatment: IV or subcutaneous magnesium sulphate under veterinary supervision.
• Prevention: Magnesium supplementation (Cal-Mag, magnesium-enriched water) during high-risk periods (spring flush, autumn).

Integrated Metabolic Disease Prevention

• Transition cow management as a core farm health plan focus
• Dry cow nutrition formulated by a ruminant nutritionist
• Regular body condition scoring (target BCS 3.0-3.25 at drying off)
• Post-calving monitoring protocols with cowside testing

Key Takeaways

Metabolic diseases cause significant, preventable welfare harm in dairy cows. Proactive transition cow management, appropriate nutrition, and post-calving monitoring reduce their incidence — protecting both individual cow welfare and herd productivity during the most vulnerable period of the production cycle.