Bovine Ketosis: Welfare Science and Prevention

Key Facts

• Clinical ketosis affects 5-15% of cows; sub-clinical ketosis affects 40-60% in the first weeks of lactation
• Negative energy balance causes fat mobilization and ketone body accumulation in the blood
• Clinical signs include reduced appetite, sweet acetone breath, reduced milk yield, and occasionally neurological signs
• Treatment with propylene glycol, IV dextrose, and glucocorticoids addresses clinical cases
• Prevention through transition cow management is far more effective than treatment of established cases

Welfare Considerations

Ketosis causes significant welfare suffering through appetite suppression and secondary disease predisposition. Sub-clinical ketosis is particularly important from a welfare perspective: cows show no obvious signs but have measurable immune suppression leading to increased mastitis, metritis, and displaced abomasum risk. Blood or milk BHB monitoring detects sub-clinical ketosis before secondary diseases develop. The transition period is the critical welfare window for dairy cow metabolic health.

What You Can Do

• Monitor fresh cows with BHB testing in the first 2 weeks of lactation to detect sub-clinical ketosis
• Administer propylene glycol to cows scoring positive for sub-clinical ketosis
• Ensure smooth calving with minimal stress — calving difficulties increase ketosis risk significantly
• Feed a balanced transition diet avoiding excess energy in the dry period and inadequate energy post-calving
• Body condition score cows regularly and target 3.0-3.25 at calving — over-conditioned cows are at highest risk