Association between milk yield, milk composition and patterns of peak in Somatic Cell Counts (SCC) were analysed in 4006 Dutch herds with 1 962 752 lactations. Definitions of peak patterns were based on 3 or more consecutive test days, and differentiated between short and long periods of increased SCC. There was a close association between milk yield at start of lactation, without or before SCC-peaks, and the incidence of SCC-peaks. The higher the milk yield, the more likely that SCC-peaks occurred. During peak periods milk-yield dropped, especially for the short intense pattern. Milk yields did not reach pre-peak levels after SCC-peaks. Fat-protein ratios were non-linearly related to SCC-peak rates. Both a lower and a higher fat/protein ratio at the start of lactation increased the risks of SCC-peaks. Across herds there is variation in the association between milk yield and SCC-peaks.
- clinical mastitis
- production losses