Blood Calcium Levels Around Calving

Understanding Milk Fever in Dairy Cows

Hour -24 from calving
Before calving - Normal calcium levels

Normal Cow

  • • Slight calcium dip after calving
  • • Stays above 2.0 mmol/L
  • • Quick recovery within 48 hours
  • • No clinical signs

Subclinical Milk Fever

  • • Drops to 1.75-2.0 mmol/L
  • • No obvious symptoms
  • • Reduced milk production
  • • Slower recovery (3-4 days)
  • • Increased disease risk

Clinical Milk Fever

  • • Falls below 1.4 mmol/L
  • • Down cow, unable to stand
  • • Cold ears and extremities
  • • Requires IV calcium treatment
  • • Can be life-threatening

Key Prevention Strategies

Pre-Calving (Dry Period)

  • • Low calcium diet to prepare calcium regulation
  • • Avoid high calcium forages
  • • Consider anionic salts (DCAD diet)
  • • Monitor body condition

Post-Calving

  • • Oral calcium boluses immediately after calving
  • • Monitor high-risk cows closely (older, high producers)
  • • IV calcium for clinical cases
  • • Continue calcium supplementation for 2-3 days
Based on research patterns in milk fever studies. Normal blood calcium: 2.1-2.5 mmol/L. Clinical milk fever occurs when calcium drops below 1.4 mmol/L. Subclinical cases (1.75-2.0 mmol/L) often go unnoticed but impact production and health. Always consult your veterinarian for specific cases.