Postpartum Inflammation in Cows May Indicate Health Risks

On September 22, 2026, Dr. Jessica McArt, a professor and dean at Cornell University's College of Veterinary Medicine, noted that inflammation is an expected response after calving. However, distinguishing between normal inflammation and more extreme cases is crucial. Researchers are increasingly focusing on the biological responses in the early postpartum days rather than merely diagnosing diseases.

In a study involving 266 multiparous Holstein cows across four New York dairy farms, McArt and her colleague Jackson Seminara assessed inflammation markers, haptoglobin and serum amyloid A, at two days in milk (DIM). Their findings indicated that higher inflammatory marker levels were linked to several negative outcomes: decreased milk production in the first 10 weeks of lactation, reduced rumination and activity during early postpartum, increased risk of dyscalcemia, and a higher likelihood of herd removal within the first 305 DIM. McArt emphasized that increased inflammation correlated with more adverse events.

While the study was observational and did not confirm causation, it raises important questions about whether the inflammatory response can serve as an early indicator of cows struggling with the transition to lactation.

Further research by McArt’s team involved monitoring 45 cows intensively, with frequent blood sampling and assessments of milk production, rumination, and activity. They observed notable differences in activity and eating patterns at just 2 DIM, suggesting that inflammation could signal variations in recovery trajectories soon after calving.

Additionally, a 2026 study by Kathryn Bach and colleagues, including McArt, examined the effects of calcium supplementation on 545 multiparous Holsteins. Cows were either given calcium boluses at 2 and 3 DIM or received no supplementation. Those with elevated haptoglobin levels at 2 DIM showed significant improvements in milk production and fertility outcomes after receiving calcium. This raises the intriguing notion that inflammation could help identify which cows could benefit most from specific interventions.

Currently, although associations between haptoglobin levels and health risks have been identified, these values are not yet standardized for on-farm decision-making. Further research is needed to determine actionable haptoglobin thresholds that could guide management practices.

Finally, translating these biological signals into practical tools for veterinarians and dairy farm teams is essential. While blood measurements can reveal differences in cow health, the future may involve integrating these biomarkers with ongoing farm data on activity, rumination, and milk production. The aim would be to inform targeted interventions based on each cow's individual needs.