Risk Factors for Tail Alterations on German Dairy Farms

Tail alterations represent an animal welfare concern in dairy cows. The objective of the present study was to identify the risk factors associated with the presence of deviated and shortened tails on 765 German dairy farms. Farm visits, questionnaires, and analyses of milk yield records were conducted, and regression analyses were performed at the animal- and farm-level. At the farm level, a higher percentage of deviated tails in farms was associated with deep cubicles, a higher average oblique rump length of the five largest cows in tie stalls, a higher care ratio, and German Holstein as the predominant breed. At the animal level, lameness in loose housing and higher parity were associated with a higher percentage of deviated tails. The presence of shortened tails was associated with the percentage of deviated tails, as well as with the presence of manure scrapers in loose housing at the farm level, as well as with the higher fat-to-protein ratio in milk at the animal level. The occurrence of tail deviations was associated with health and management factors, while shortened tails were associated with acute injuries or metabolic disorders. Performing longitudinal studies would improve the understanding of the pathogenesis of tail alterations.