Somatic cell count patterns. Improvement of udder health by genetics and management

Keywords:Pathogen-specific clinical mastitis, Somatic cell count patterns, Genetic selection programs, Udder health management

Research described in the thesis provideinsight in the use of patterns of peaks in somatic cell count (scc) in genetic selection and mastitis control programs. Patterns of peaks insccduring a lactation were defined based onsccrecorded on consecutive test-days, and are based on biological understanding of pathogens and of the immune system of the cow. Results showed that selecting against occurrence ofsccpatterns was more effective to decrease the natural susceptibility to mastitis-causing pathogens, than selection for lower lactation-averagescc. Patterns of peaks insccare also proven to be useful as basic tools for health management advice, as they can distinguish between casesofmastitis associated with either environmental or contagious pathogens, whereas the currently used primary traits were indicative for contagious, but not for environmental mastitis.