Haptoglobin is an inflammation marker which is virtually non-existent in healthy cows but increases over 100-fold at the onset of an inflammation event. Previous studies have reported an association between elevated haptoglobin concentrations in early lactation with metritis, decreased milk production, and decreased risk of conception. In a large transition cow field study, we measured haptoglobin concentrations in primiparous and multiparous cows and established critical thresholds for predicting health disorders, determined the association between elevated haptoglobin concentrations and milk production and reproductive performance, and identified herd-alarm for haptoglobin that are associated with herd-level changes in health, milk, and reproductive performance outcomes.