Postpartum distribution of costs and disorders of health.

More than 17,000 events from 1,305 lactations of 551 cows in two herds were analyzed to quantify the distribution of costs and disorders of health during a lactation. Categories were mammary, reproduction, locomotion, digestion, respiration, other, insemination, and total. The largest costs and most disorders were associated with initiation of lactation rather than period of peak daily milk yield. Mammary and reproductive costs were 71% of total health cost in the first 30 days postpartum. Mammary and reproductive costs were 55% of the total health cost in an average 30-day interval. Insemination cost was 50% of the total health cost between 60 to 89 days postpartum. Parturition and extended days open were periods of large reproductive cost. Postpartum distributions of health cost and health disorders were similar implying that the prices assigned for severity added little information to counting disorders.