Is Bloodless Dehorning Really Painless?
This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the January 2015 issue of Canadian Cattlemen magazine and is reprinted on the BCRC Blog with permission of the publisher.
In January 2016, Canada’s Code of Practice for the Care and Handling of Beef Cattle will expect beef producers to consult with their veterinarian and use pain control when dehorning calves after the horn bud has attached. In other words, producers will be expected to use pain control when dehorning calves older than 4 months.
Earlier dehorning is easier for you and the calf. The best way to dehorn is to use homozygous polled bulls. Second best is to disbud before the horn has attached to the skull. Older calves have larger horns, suffer larger wounds, likely experience more pain, and have a longer recovery period. As one wag has suggested, the longer the horns are attached to the calf, the more attached the calf is to its horns.
Age is the biggest factor in minimizing pain. But a team from Kansas State University recently reported that dehorning method is also important, especially in older calves (“Effects of three dehorning techniques on
behavior and wound healing in feedlot cattle”; J. Anim. Sci. 92:2225).
What they did:
Forty horned beef calves averaging 690 lbs were divided into four groups of ten. One group was not dehorned. The second group had the horn tips removed at the point where the horn was about 3 cm in diameter. The third group was mechanically dehorned using a keystone (guillotine) dehorner, and the wound was heat-cauterized to minimize bleeding. The fourth group was dehorned using a Callicrate band (also used to castrate feedlot bulls) at the base of the horn. The band is intended to block blood flow to the horn. This should kill the living horn tissue, and the horn eventually falls off. The cattle were observed daily for a variety of behaviors (vocalization, depression, gait, posture, appetite, lying) and wound healing for the month after dehorning.
What they learned:
During the operation, the tipped cattle made no more noise than the control cattle. This suggests that tipping wasn’t very painful. The nerves in the horn do not extend all the way to the tip. So if the operation is done properly, tipping is probably more stressful than painful. Cattle in the two dehorning treatments made more noise, but at different times. The mechanically dehorned cattle vocalized more than the banded cattle during the operation, but the banded cattle vocalized more than the mechanically dehorned cattle in the days following the operation. This suggests that the pain of mechanical dehorning decreased in the days after the operation, while the pain of band dehorning lasted much longer.
Cattle dehorned with bands were also more likely to lie down with their hind legs extended or flat on the side (indicators of comparative discomfort), while cattle in the other three groups lay more normally. Banded cattle tended to have worse scores for depression (reluctant to move unless approached closely), compared to the other three groups (bright, alert, and responsive when the pen was approached). Banded cattle tended to stand and move abnormally (head tilted, hunched posture) than cattle in the other groups (normal to stiff gait). These abnormal lying, depression, and posture behaviors were more noticeable in the banded cattle than for cattle in the other three groups throughout the entire four weeks of observation.
Bleeding did not differ among the four groups in the first week after dehorning, likely because the wounds were cauterized in the mechanically dehorned calves. In the first week, increased redness was seen around the dehorning wounds in some mechanically dehorned calves. Inflammation became apparent in the banded calves after three weeks; bleeding started when the horns fell off. Three horns had fallen off the banded group by the end of the month, while the bands themselves fell off four animals.
What it means:
When done properly, tipping does not appear to be painful. Tipped horns can still cause serious carcass bruising. However, tipping large horns (e.g. grass cattle entering the feedlot with lengthy horns) does reduce the risk that the horn will be accidentally broken off during subsequent handling. Mechanical dehorning causes acute, but relatively short-lived pain. In contrast, band dehorning is more likely to fail, and causes chronic, prolonged pain.
Contrary to the manufacturer’s suggestion, bloodless isn’t necessarily more humane. While a larger study with more cattle may have found measurable differences in behavior or wound healing between the other three groups, these results clearly indicate that band dehorning greatly prolonged the discomfort and healing process.
Results of the Canada’s latest National Beef Quality Audit found that fewer fed cattle had horns in 2011 (12%) than in previous audits conducted in 1999 (30%) and 1995 (40%). In 2016, the next National Beef Quality Audit will assess whether this progress is continuing.
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