Why So Many Broken Tails?
The acceptable threshold for broken tails in adult dairy cows listed in the National Dairy FARM Program standards is 5%.
And yet a recent study published in the Journal of Dairy Science showed that nearly half of the animals in a 229-cow sample from a single dairy herd had broken tails.
Lead author of the study, Hannah Olsen from the University of Wisconsin-River Falls, said broken tails represent an animal welfare concern and result from improper handling. She and her team of fellow researchers conducted the study to determine what factors, if any, were associated with broken tails. They found:
- Of the 229 cows in the 1,350-cow Holstein herd evaluated, 105 -- or 46% -- showed visual evidence of a broken tail.
- Multiparous cows had a greater prevalence of broken tails than first-calf heifers.
- Cows repeatedly treated for mastitis were significantly more likely to have a broken tail compared to their herd mates that never were treated for mastitis, or treated only once.
Essentially, the longer cows lived on the dairy and the more frequently they were handled for a health event, the more likely they were to have a broken tail.
The authors noted that industry guidelines state “the use of tail twisting as a handling method to prompt forward cattle movement involves releasing the tail after the animal moves forward, and never involves continuously twisting the tail.”
While they acknowledged limitations in the study due to small sample size and confinement of evaluation to just a single herd, Olsen and her team believe the results are telling of an industry management issue that needs further attention.
“The large percentage of cows with broken tails in our study indicates that the problem of broken tails was under-addressed, and further investigations are needed to determine the causes behind broken tails, as well as management techniques to help prevent tails from being broken,” they stated.
