INFLUENCE OF FEEDING MANAGEMENT, CONCENTRATE INTAKE AND ENERGY-INTAKEON THE RISK OF HYPERKETONEMIA IN SWEDISH DAIRY HERDS

The risk of hyperketonaemia (clinical and subclinical ketosis) and how it is influenced by feeding and management routines was analyzed in 2 91-354 dairy herds over a 3 year period. The overall frequencies of co ws with milk acetone greater than or equal to 0.40 mM ranged between 4 .2 and 6.2% in Parity 1 and 12.7 and 13.8% in Parity 2+. The incidence was probably underestimated, as samples were taken once per 30 day pe riod. The risk of hyperketonaemia was higher at low than at high feedi ng frequencies; most odds ratios (OR) were in the range of 1.0-2.7 for two versus four meals per day, The effect of feeding frequency was mo st evident on high concentrate rations. A larger amount of concentrate in early lactation was deemed to increase the risk of hyperketonaemia , but not consistently so; OR ranged between 0.4 and 2.7, with highest risks for the Swedish Red and White breed. Feeding forage before conc entrate and feeding the cows a meal close to milking time reduced the risk of hyperketonaemia, but the results were inconsistent. Hyperketon aemia occurred more often in herds with feeding barriers than in short stall without feeding barrier. Our findings suggest that a high feedi ng frequency and a cautious feeding strategy of concentrate early in l actation are important factors in the prevention of subclinical or cli nical ketosis.