Management factors affecting herd average test-day somatic cell count in dairy cattle farms

Since mastitis is a multifactorial disease, its risk factors and their consequences for milk quality need to be examined from several perspectives. This study aimed to investigate how different udder health management factors affect the herd average test-day somatic cell count (HSCC), calculated from individual cow samples collected during monthly milk recording. A total of 33 large Hungarian dairy farms (with a total of 32,886 cows) were surveyed using a questionnaire. Data were collected on the main production parameters and several udder health management factors, including milking practices, housing, bedding, dry-off procedures, mastitis treatment and mastitis prevention. The data were analysed using multi-way ANOVA models. To create appropriate statistical models, three main groups of udder health management factors were defined: milking practices, dry-off procedures and mastitis management. Each group included three management factors which were analysed for potential associations with HSCC. Farms where dry-off therapy was performed at least weekly and teat sealants were used tended to have lower HSCC values, whereas farms where mastitis case severity was scored tended to have higher HSCC values. Udder health management factors varied widely across the surveyed farms and among the three main groups of management factors, dry cow management had the greatest impact on HSCC.