Survey on the occurrence of milk fever in dairy cows and the current preventive strategies adopted by farmers in New South Wales, Australia

The aim of this study was to investigate general and specific strategies adopted by New South Wales (NSW) farmers to prevent milk fever (MF) and its occurrence at calving within their dairy herds. Of 300 farmers in the NSW dairy region randomly chosen and sent questionnaires, descriptive analysis of the returned data was performed for 102 questionnaires. To identify the various strategies used to prevent MF and its incidence, farms were classified as having a high- or low- incidence (< or >3% MF,respectively). The data were analysed using a multi variable logistic regression model and backwards step wise elimination to identify significant preventive strategies adopted by farmers having a low or high-incidence of MF. Based on the 102 responses, the median incidence of MF in the NSW dairy region was 3% (range 0'30%). The farms with low MF incidence practised specific MF control strategies, such as feeding dry cows separately, grain supplementation and feeding a low-potassium ration before calving and using a commercial ration mix immediately after calving. The time to first milking post-calving was on average 13.6 h on the low-incidence farms compared with 21.1 h on the high-incidence farms.The low median incidence of MF (3%) in NSW was probably related in part to awareness of the importance of feeding a low-potassium, high-grain diet before calving. However, the incidence of MF was relatively high.