Milk Producer - April 2009 - (Page 36)

RESEARCH By Katherine Tuerke Ideal procedure Dehorning calves at a younger age may help you cut back on pain medications D ehorning procedures vary greatly across farms due to the different tools, numerous techniques and a wide range of expertise available. With no standardized approach, it’s been difficult for cattle farmers and veterinarians to determine which procedure is least painful. University of Guelph researchers are looking at a more standardized and practical dehorning procedure farmers and veterinarians can rely on. Studies by professor Todd Duffield in the department of population medicine show dairy calves should ideally have their horns removed when they are no more than four weeks old. A local anaesthetic should be used in all calves to help manage pain, followed by a non-steroidal anti-inflammatory drug (NSAID) if the calves are older than four weeks. “The dehorning procedure is necessary, as it minimizes the risk of injury to farmers and other cattle,” says Duffield. “But the methods currently being used can be improved.” A survey conducted by Duffield showed about 40 per cent of dairy farmers give their calves a local anaesthetic during dehorning. The remaining 60 per cent of farmers who don’t use a local anaesthetic during dehorning cited cost, time and lack of awareness as their reasons for not doing so. But Duffield believes farmers and veterinarians, not to mention livestock, could benefit significantly from a local anaesthetic, such as lidocaine. It’s inexpensive and easily available. Local anaesthetics numb the horn region and minimize pain from nerve and tissue damage during dehorning. Duffield compared two groups of calves’ behavioural responses to pain. One group was treated with lidocaine before dehorning. The other did not receive a local anaesthetic. The treated group showed substantially fewer feet stomps, less falling and did not display rearing or kicking behaviour. As well, the calves’ physiological responses showed lower heart and respiration rates in those treated with lidocaine. Timing is another important consideration, says Duffield. When he closely examined ear flicks (a behavioural response to pain) in young calves during dehorning, he found calves less than four weeks old showed appreciably fewer ear flicks than a group of calves eight to 12 weeks old. “A calf’s horns are smaller when they’re young, so the dehorning procedure doesn’t inflict a very large wound,” says Duffield. “We see fewer physical responses from the calves, and it’s easier for farmers to handle them during this procedure.” NSAIDs reduce pain when there’s inflammation. Duffield found six- to 10-week-old calves treated with an NSAID displayed fewer head shakes, head rubs and ear flicks. The NSAID had no additional benefits for calves less than four weeks old. That means additional NSAID costs can be avoided by dehorning calves at a younger age. Duffield’s next studies will focus on how other NSAIDs minimize pain from difficult calvings and abdominal surgeries, such as C-sections. Researchers suggest dairy calves have their horns removed at no more than four weeks old. Katharine Tuerke is a student writer with the University of Guelph’s office of research. Other research collaborators include professors Kerry Lissemore and Suzanne Millman, department of population medicine, veterinary technician Shelley James, Master’s student Anneliese Heinrich and summer research students Andrew DeHaan, Barry Milligan and Laine Misch. This research has been supported by Boehringer-Ingelheim, the Ontario Ministry of Agriculture, Food and Rural Affairs and the Ontario Veterinary College Summer Leadership and Research Program. 36 | April 2009 | MilkPRODUCER

Table of Contents for the Digital Edition of Milk Producer - April 2009

Milk Producer - April 2009
Contents
Editor's Notes
DFO Chair's Message
Dairy Update
DFC Promotion
Industry Roundup
National Policy
Triumph Over Tragedy
Policy Update
Research
Applied Science
Ruminations
Markets
New'N'Noted
Back Forty

Milk Producer - April 2009