Preventive strategies and risk factors for milk fever in Danish dairy herds: A questionnaire survey

Milk fever is a commonly recognized production disease in dairy cows around parturition. The aim of this questionnaire survey was therefore to investigate milk fever preventive strategies used in Danish dairy herds during 1998, to explore the reasons for choosing a specific strategy, and finally to evaluate possible risk factors for milk fever occurrences.A random sample of 230 milk producers (MP) was drawn from the Danish Cattle Database. A telephone interview (TI) was used to collect data. A sub-sample of 25% MPs was chosen by systematic random sampling and interviewed a second time (TI2). Descriptive analysis of all answers was performed. The agreement between TI1 and TI2 was evaluated using Cohen's kappa coefficient and the overall intra-MP agreement. Risk factors (such as housing systems or use of milk fever preventive strategies) for differences in milk fever incidences between herds were evaluated using logistic regression.This investigation revealed that Danish MPs focused on a few well-described milk fever preventive principles and other management methods, such as reduced milking and management of body condition. There was no significant difference in risk of developing milk fever using different prevention strategies (p = 0.80). Furthermore, the logistic regression did not indicate an association between reported milk fever cases and the assessments of this as a problem or not (p = 0.09). Tie stalls increased the risk of milk fever compared to loose housing systems (p = 0.019). There was a significant difference in risk of milk fever between parities. The overall milk fever incidence risk was 3.0%.