Sarah Adcock is a dairy researcher with a mission. As a doctoral student at the University of California-Davis, she conducted trials assessing animals’ pain associated with disbudding, as well as strategies to mitigate this pain. Soon, she will join the Department of Animal and Dairy Sciences at the University of Wisconsin-Madison as an Assistant Professor of Animal Welfare.
At the 2020 Annual Conference of the Dairy Calf and Heifer Association, Adcock shared her insights on best practices for disbudding, as well as her perspective on the future of the procedure.
“We’re seeing a trend on U.S. dairy farms of performing the task on calves earlier in life,” she said. “Mechanical horn removal after 8 weeks of age – true dehorning – is on the decline, and more dairies and calf operations are removing the horn buds before they attach to the skull at 8 weeks, which is classified as disbudding.”
She said the two main methods of disbudding – caustic paste and hot-iron cautery – both are viable practices. Disbudding with caustic paste very early in life, at a week or less of age, also is on the rise, although there is no evidence that performing it near birth is any less painful.
“Research study results are mixed as to which of the two methods is more or less painful, but we know they both cause pain, regardless of the calf’s age,” stated Adcock. “As an industry, pain management should be adopted as a standard of care in the disbudding practice for all calves. Both the American Association of Bovine Practitioners (AABP), and the National Dairy FARM program, now endorse pain relief with disbudding as a standard practice.”
The most comprehensive approach to pain management is a cornual nerve block on both sides of the skull, accompanied by a long-acting, non-steroidal anti-inflammatory drug (NSAID) to mitigate pain when the block wears off. Sedatives also can be used to make handling easier, but they do not provide pain relief, so a nerve block and NSAID both still are necessary.
This video has been prepared by Adcock and her colleagues to demonstrate the proper method of administering disbudding pain relief.
Adcock noted that there is no clear evidence for a correlation between average daily gain (ADG) and pain mitigation with disbudding. But while it is not a production issue, it definitely is a consumer issue. She said it is important that disbudding practices continue to evolve to ensure sustainability for the dairy industry. This may be accomplished in one or more of the following ways:
Pain management for all – The most recent USDA National Animal Health Monitoring System (NAHMS) study in 2014 showed pain management was being used by just 30% of producers performing hot-iron disbudding, and 6% of those using caustic paste. However, a U.S. survey in 2015 showed that, of those who responded, 83% of dairy producers, 92% of veterinarians, and 92% of consumers believed pain relief should be provided for disbudding. Given the AABP and FARM program endorsements, Adcock is hopeful the practice will continue to grow.
Alternative methods – A few studies have explored potentially less invasive procedures for disbudding, but with limited success to date. Injecting clove oil under the horn bud had a 67% failure rate, and cryosurgery by applying liquid nitrogen to the horn bud had a 100% failure rate. Still, refinements to these practices or other practices might emerge with further research.
Polled genetics – Adcock said 88% of U.S. beef cattle are polled. In the dairy industry, polled genetics remain fairly limited, hampered by concerns about inbreeding and slowed genetic progress. However, polled genetics now are officially recommended by both the American Veterinary Medical Association and the World Organization for Animal Health. Likewise, many U.S. food processors and retailers are calling for naturally polled dairy animals, including Danone, Dunkin’ Donuts, General Mills, Kroger, Nestle, Starbucks and Wal-Mart.
Gene editing – This procedure directly introduces the polled gene into the genome of elite sires, making it possible to create polled offspring without disrupting genetic progress or increasing inbreeding. Gene editing awaits regulatory approval and may meet resistance given consumer sensitivity to GMOs. But a 2019 study showed 66% of Americans support gene editing for hornless cattle.
“If social acceptance for disbudding continues to decrease, polled genetics will grow in importance,” said Adcock. “If you haven’t already started, it’s a good idea to incorporate polled genetics in your herd whenever possible.”