Cow mortality in three dairy herds: preliminary study (1994-2004)

Abstract

The objective of this study was to determine the average annual mortality rate of dairy cows in three dairy herds of the Valdivia province, Chile, from 1994 to 2004; in addition the most common causes of death among the cows were determined. The information was gathered from 205 individual record cards of dead cows and related annual inventories, and analysed using Excel. The average gross mortality rate for the three farms was 4.8% whereas the rate of annual gross mortality for farm A was 6.8%, farm B was 4.2% and farm C was 3.2%. The most frequent causes of death when considering the three farms together were calving problems (21%), undetermined causes (16.1%) and digestive disorders (15.6%). The highest mortality percentages were reached between April and September. Most of the cows died when they were seven years old (17%), with the first stage of the lactation period showing the highest porcentage of dead cows (61.8%). It was concluded that there is a high mortality rate in dairy farms and that the causes of death were different depending on the farm, but in general they were related to calving, undetermined causes, and digestive disorders.