High risk of dairy cow mortality in early lactation.

Abstract

On-farm mortality among dairy cows constitutes a major problem in modern dairy production. Detailed knowledge about when cows die may help guide the prevention of future deaths. Data from 46,927 on-farm dairy cow deaths reported to the Danish Cattle Database were analysed to evaluate the distribution of deaths in relation to time after calving and the effect of parity and breed. Of all on-farm deaths, 15.2% occurred within 7 days after calving, 32.2% within 30 days and 49.4% within 90 days. Older cows generally died sooner after calving compared to younger cows, and Jersey cows died later than other breeds. The results are based on a large and reliable dataset but include only data from Danish dairy cows. The distribution of on-farm deaths was very uneven, with a large proportion of deaths occurring during the first few weeks after calving, especially in older cows.