Recording of culling reasons in Danish dairy cows

Culling in dairy cows has major impacts on production economy and animal welfare, and has been described and evaluated in many studies. Information about why a cow is culled (culling reason) may be useful for many different purposes. Still, the present study is the first to evaluate explanatory factors for recording of culling reasons. Danish dairy farmers are required to report the culling mode (slaughter, unassisted death, or euthanasia) to the Danish Cattle Database. Further, the reporting of one or two culling reasons - from a list of options - is possible but not mandatory. Data from 281,682 cows culled in Danish dairy herds in 2020 and 2021 were analyzed. The mean age at culling was 1,845 days, 83.3 % of the culled cows were slaughtered, 10.2 % died unassisted and 6.5 % were euthanized. In 66.8 % of the culled cows, the farmer had reported at least one culling reason. The most frequent culling reasons for slaughtered cows were milk production (29 % of all culling reasons reported), followed by reproduction (25 %), and udder health (16 %). For unassisted dead cows, metabolic/ digestive disorders were most frequently reported (25 %), followed by unknown reasons (18 %), and udder health (15 %). For euthanized cows, accidents were most frequent (29 %), followed by locomotor disorders (18 %), and metabolic/digestive disorders (17 %). Culling mode, as well as culling reasons, differed by parity and breed. Results from a logistic regression model showed that the odds of at least one culling reason being reported was significantly higher in Jersey cows compared to other breeds. Compared to Holstein cows, the odds of a reason being reported was 2.5 times higher in Jersey cows. The odds increased with increasing parity of the cow. In herds with a high mean milk yield and a low somatic cell count, the odds of reporting a culling reason was higher than in herds with lower milk yield and higher somatic cell counts, and the odds of reporting a culling reason increased with an increasing number of disease treatments recorded per cow per year.