“In our study, we commonly saw up to 20% of the herd having some form of damage to their tails, so although we expect it should be 0%, that’s not what is seen on the ground and we need more information to help understand what realistic expectations are.”

The study used data from the animal welfare monitoring programme WelFarm. Farms that are engaged with the programme through their veterinarian are offered an annual tail audit, where every tail is inspected by a veterinarian or technician, and injuries are classified according to a standardised classification. The programme provided data for more than 54,000 head of cattle spanning four seasons.

“All farms in the study had some proportion of cows with some form of damage to their tail, which was consistent with the results of a study in Ireland that reported 90% of their study farms had cows with damaged tails at each of two visits,” Moono says.

“And we found there was variation between regions and wide variation between farms.”

The researchers were primarily trying to find out how many cows had deviated tails, but they were also looking at how many cows had shortened tails or tails with soft tissue or any other form of damage.

Tail amputation, or docking, is generally assumed to have formerly been carried out as routine management practice on farms. It was largely used as an aid in the control of leptospirosis, and it was also thought that udder hygiene pre- and post-calving could be improved by docking tails. But tail docking in any form was made illegal in New Zealand in 2018.

It is thought that shed design or management factors may be important in influencing the incidence of tail damage. Staff training could be another factor. But it is hard to determine exactly what is having an impact and what the risk factors are. There were no welfare breach investigations underway for any of the farms in the study.

“In our conclusion, we recommended further work to be carried out to explore individual farms, following animals across multiple seasons to help determine what could be causing the problems,” Moono says.

“Cows can move a lot in their life, spending time at grazing, for example, and because we don’t know where the problem is coming from, if there was some work into checking between the movements it would be easy to track when and where the problem is occurring.”

In the published research, it is proposed that tails need to be monitored at least annually from early life to determine the high-risk age when tail damage is likely to occur. This is supported by many veterinary clinics that now offer a tail scoring service due to the increased focus on animal welfare.

Another four-year study into tail damage, this one supported by the Ministry for Primary Industries’ Sustainable Food and Fibre Futures, is also underway. It is driven by veterinarians who are trying to answer many of the questions surrounding tail damage, including trying to determine the causes of specific injuries and what changes may improve outcomes.

“We hope this work will assist the New Zealand dairy and veterinary sectors, as well as the regulatory authorities to engage and support a national approach to tail scoring,” says Mark Bryan, veterinarian and managing director of VetSouth.

“This will give all stakeholders access to meaningful benchmarks and encourage them to take further steps to understand and minimise the risk for tail injuries in dairy cattle.”