This study aimed to determine herd prevalence of tail alterations (deviated and shortened tails) on farms in Germany. In total, 86,355 cows on 765 dairy farms in three regions (North, South, East) were assessed for presence or absence of deviated and shortened tails. Mean herd prevalence of deviated tails was 10.00% with a median of 7.89%. The mean herd prevalence of shortened tails was 1.07% with a median of 0%. Herd size, energy-corrected milk yield (ECM), and husbandry system were associated with herd prevalence rates of tail deviations and shortened tails. Herd prevalence increased with herd size (Spearman’s ρ = 0.586) and median ECM (ρ = 0.404). 28.10% farms had a herd prevalence <5% tail alterations, while 26.41% had a herd prevalence of >15%. Our findings plead for including monitoring of tail alterations in animal welfare assessments of dairy farms. The National Dairy FARM Program in New Zealand aims to achieve a herd prevalence of less than 5%. A herd prevalence of >15% tail alterations is regarded as the critical threshold requiring clarification and elimination of causes. It is imperative that all dairy farms strive to achieve a herd prevalence of less than 5% and welfare protocols are duly adjusted.
