A glimpse into tail tip lesions in dairy cows – have we missed something?

Objectives

Tail tip lesions have been observed in fattening cattle with prevalences varying from 35 % to 76 %. These lesions include hairless areas of the tail tip, laceration and / or infection leading to inflammation of larger parts of the tail as well as necrosis. This often results not only in economic loss but has also adverse effects on animal health and welfare. While there are several studies on this issue in fattening cattle, data on tail tip lesions in dairy cows are scarce. However, own previous studies have shown that a variety of lesions on the tip of the tail also occur in dairy cows. The objective of this study was to investigate the prevalence of tail tip lesions in dairy cows.

Material and methods

A developed overview of different tail tip lesions in dairy cows and their manifestations was used to examine cows on six different German dairy farms. After shaving the tail in the region of the switch, cows were examined for the prevalence of 1) lesions on the very tip of the tail, 2) annular lesions, 3) hyperkeratosis, 4) swelling, 5) axis deviation, 6) thinning or 7) fibroma on the distal part of the tail. Examination was performed by one single person. All cows were kept in loose housing conditions on slatted or solid floors, with or without automatic scrapers. Herd sizes varied between 51 and 162 cows. A total of 500 Simmental or Holstein Friesian dairy cows were examined. To calculate the prevalence per lesion, the number of animals affected by the corresponding lesion or lesion manifestation was divided by the total number of animals examined. Mean prevalences were calculated per farm and for the total sample.

Results

Only one cow, out of all 500 examined cows, was free from the above mentioned lesions. 499 animals, however, were affected by at least one lesion. The most prevalent lesions were hyperkeratosis, ranging from 72.9 % to 97.3 % between herds (mean prevalence = 85.1 % ± 7.9) and swelling, with prevalences between 54.2 % and 95.9 % (mean prevalence = 73.4 % ± 18.3). Every lesion could be observed in every herd. The most severe manifestations of lesions at the very tip of the tail, according to our previously established overview, are bleeding or necrosis up to part loss of the distal part of the tail. We found bleeding or necrotic tail tips in four of the six farms, with prevalences ranging from 0.66 % to 26.03 % (mean prevalence = 8.36 % ± 11,39).

Conclusions

To our knowledge, this is the first study to show prevalences of different tail tip lesions in Simmental and Holstein Friesian cows on German dairy farms. The high prevalence of the lesions in all farms evaluated, under different housing conditions and in both breeds, and the occurrence of severe manifestations such as bleeding or necrotic tail tips, may indicate an animal welfare problem that has apparently gone unnoticed until now. Further research is needed to assess whether this phenomenon occurs on other farms and in different regions and countries as well, and to elucidate the aetiology, pathogenesis and risk factors of the lesions observed.

Funding: Parts of the research wer funded by the Tönnies Forschung, Rheda, Germany