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Dehorning hurts, but we can do something about it

Asadeh Behnam-Shabahang, Heather Neave and Marina A.G. von Keyserlingk for Progressive Dairyman Published on 24 May 2016
Pain control for dehorning

There is no doubt that dehorning (also referred to as disbudding) is painful. Given that much of the horn as well as the skin surrounding the horn is highly innervated, dehorning elicits immediate and acute reactions from calves.

However, the pain from dehorning can and should be minimized.

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In recent years, abundant research has been published on effective and affordable means to control the pain caused by dehorning. Many of these studies compared calves that received no pain mitigation to calves that received either a sedative, a local anesthetic (e.g., lidocaine; relieves pain up to two hours), analgesia (e.g., meloxicam; relieves pain for 24 to 48 hours) or a combination of these.

The available scientific evidence clearly shows calves receiving pain control exhibit fewer behavioral (i.e., ear flicks) and physiological (i.e., heart rate and cortisol levels) responses associated with pain compared to calves that do not receive any medication.

It is therefore no surprise that the American Veterinary Medical Association recommends anesthetics and analgesics for dehorning. The American Association of Bovine Practitioners has released its own guidelines for the timing, restraint and approved methods of administration of pain relief at dehorning.

And NMPF’s Farmers Assuring Responsible Management, or FARM program, recommends disbudding or dehorning is performed before 8 weeks old and that producers follow “pain control protocols agreed upon by the dairy farmer and veterinarian.”

Stakeholder views

A recent study from the University of British Columbia, published in the journal Animal Welfare, shows the majority of stakeholders, including those involved in the dairy industry (e.g., dairy producers and farm workers) and lay citizens, are in favor of pain relief for dehorning calves.

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Participants, predominantly American and Canadian, were grouped into five different backgrounds: Dairy producers and farm workers; veterinarians; students, teachers or researchers; animal advocates; and people with no involvement in the dairy industry.

Using an online survey platform, they were asked the question after reading a brief background paragraph on the topic of dehorning, “Should we provide pain relief for disbudding and dehorning dairy calves?” and to provide a simple explanation for their choice.

Of the 354 participants, 90 percent answered “yes,” including 29 of the 35 producers. The top three reasons for answering “yes” were:

  1. The procedure produces pain.

  2. While animals are useful for food production, they should not suffer in the process.

  3. There is pain involved and the means are readily available to address the pain.

How many use pain control in the U.S. and Canada?

Although the majority of stakeholders, producers included, are clearly in support of controlling the pain of dehorning, the question remains: How many farms are actually using this practice?

In 2004, a survey of 207 producers and 65 veterinarians in Ontario showed that of the 78 percent of producers (161 out of 207) who dehorned their own calves, only 18 percent (29 out of 161) used local anesthetics such as lidocaine.

Of these producers, only 12 percent (19 out of 116) used sedatives for some of their calves, and of these, 63 percent (12 out of 19) also used local anesthetics (lidocaine) in combination with the sedative.

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In the U.S., a 2005 survey of 113 dairy farmers across north-central and northeastern U.S. states identified that only 12.4 percent of the producers used anesthetics on painful procedures such as dehorning and tail docking, while 1.8 percent employed the use of analgesics.

The most recent national survey from the USDA’s National Animal Health Monitoring System (NAHMS), released in 2007, reported that 14 percent of producers used anesthetics and/or analgesics when hot-iron or caustic-paste dehorning, while 21 percent used some form of pain mitigation when using the scoop, gauge and wire dehorning.

Barriers to using pain mitigation

If the available research shows pain control is effective and stakeholders appear to support its use, why do so many dairy producers in the U.S. and Canada fail to provide pain control? In the UBC study, the 4.5 percent of participants opposed to pain control gave the following reasons justifying their response:

  1. Uncertainty about the intensity of dehorning pain
  2. The pain is only temporary or short-term.
  3. Young calves experience less pain.
  4. Anesthetics and analgesics may not even be effective.
  5. Providing pain control only elongates the dehorning process.
  6. Pain control is too costly.

Examining these reasons may provide some insights. We start with the top two reasons: “Dehorning doesn’t hurt that much,” and “It only hurts for a short time.” Again, we looked to the available science for guidance.

A substantial amount of research has demonstrated that dehorning causes distinct physiological, behavioral and emotional responses in calves, and many of these studies show responses continue in the days following dehorning.

Increases in heart rate, cortisol levels, head shaking and rubbing, restlessness and demonstrating pessimism in a cognitive task are only a few of the recurring results observed in these studies, confirming that dehorning pain is not only intense but lasts for at least 24 hours following the procedure (Figure 1).

Behavioral response of calves with and without ketoprofenAnother popular reason provided by some of the participants was, “Younger calves experience less pain.” Although younger calves may recover more quickly from dehorning, studies of the tissues around the horn buds show they are already fully innervated in day-old calves.

Studies on dehorning have used calves that range from roughly 1 week to 4 months old, all describing consistent responses indicating that dehorning is painful.

Many argued, “Pain management is not that effective.” The pain management properties of anesthetics and analgesics for dehorning purposes have also been repeatedly demonstrated in numerous scientific articles.

Although local anesthetics (i.e., injectable lidocaine) are effective in numbing the initial pain of dehorning, sensation returns about two hours after the application. Post-dehorning analgesics (i.e., a non-steroidal anti-inflammatory such as meloxicam or ketoprofen) will provide pain relief for 24 to 48 hours.

Sedatives (such as xylazine), although not proven to have pain-mitigating effects, are useful in reducing handling stress induced by the dehorning procedure.

“Pain management is time-consuming” was the fourth most popular reason given by participants who said “no” to providing pain relief. Given that pain control would reduce the struggle of dehorning for both the farmer and the calf, time spent administering medications could arguably be regained in time spent physically restraining the calf.

Last, some participants argued, “Pain management is costly.” The cost of pain control for dehorning has been calculated to be 0.004 percent of the overall cost of raising a replacement heifer.

This amounts to approximately $0.50 for anesthetics and no more than $4 for a combination of sedative, anesthetic and analgesics. This is also a one-time expense in the life of the heifer.

The future

Today, it appears that less than 20 percent of U.S. and Canadian dairies routinely provide local anesthetic and just 2 percent use analgesics when dehorning their calves. The UBC study concluded that the reluctance to use pain control stemmed predominantly from a lack of education and knowledge of the efficacy of these pain-mitigating methods.  PD

Asadeh Behnam-Shabahang is an undergraduate student at the University of British Columbia. Heather Neave is a Ph.D. student at the University of British Columbia. Dr. Marina A.G. von Keyserlingk is a professor at the University of British Columbia. Email Marina A.G. von Keyserlingk

PHOTO: Today, it appears that less than 20 percent of U.S. and Canadian dairies routinely provide local anesthetic and just 2 percent use analgesics when dehorning their calves, despite the requirements outlined by veterinary associations and the Code of Practice in Canada and despite the majority of opinion that pain control should be used. Staff photo.

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