Creating a model to detect dairy cattle farms with poor welfare using a national database.

•Welfare Quality® protocol was used to assess dairy cattle welfare in 24 Portuguese farms.•15 potential welfare indicators were identified using a national cattle database.•A model was developed based on those indicators to identify farms with poor welfare.•Proportion of on-farm deaths and calving interval were associated with farms with poor welfare.•The model had 70% sensitivity and 79% specificity.