Dehorning, or disbudding, is necessary in raising naturally horned animals to keep them from injuring workers and themselves. Since cattle have a social hierarchy, horns are used to assert dominance, resulting in bruises and cuts in their herd-mates, and potentially serious injury or death to humans. The easiest way to avoid horns is to use polled genetics, however until the selection of polled sires becomes more accepted, we will have to continue to dehorn calves.
When to remove
When it comes to removing horns, younger is always better. As a calf ages, horn removal becomes more detrimental to the calf’s health and growth. This is because around eight weeks of age, the horn produces cells that attach to the skull. According to the National Dairy Farmers Assuring Responsible Management (FARM) program, best practice is to disbud calves eight weeks of age. Any attempt to permanently remove horns at older than eight weeks of age is considered a surgical procedure and should be performed by a veterinarian.
How to remove
One way to kill horn producing cells is to use caustic paste very early in life. This method causes pain, which I would describe as intense bee stings, but there isn’t a lot known about how intense the pain or its duration. Management practices, such as applying paste on day one or two of life, limiting social interaction and protecting treated calves from the rain are instrumental in the success of using paste. Many herds have success applying paste just after colostrum feeding, when the calf has a full belly and is not able to move around much. Using cordless trimmers to remove hair in the horn region before applying paste is good practice.
If you choose to dehorn with a hot iron, Michigan State University Extension recommends working with your veterinarian to develop a pain management protocol. Administration of local anesthesia (lidocaine) and non-steroidal anti-inflammatory drugs have been shown to reduce pain and quicken calf recovery.
When disbudding calves with a nerve block, you will still need to restrain the calf, often most of the resistance on the part of the calf will result from restraint, not from the actual debudding procedure.
Work with your veterinarian to perfect your technique in nerve blocking calves. To nerve block the calves you will need prescription 2 percent lidocaine HCL, an 18 gauge 1.5-inch needle and a 12 cc syringe. To find the correct place to inject the anesthesia:
- Start by locating the horn bud
- Run your hand down the side of the face towards the outer corner of the eye, feeling for a ridge
- The injection site is a slight depression just below the ridge where it ends at the outer edge of the bony orbit of the eye
Insert the full length of the needle so that the angle is down and towards the middle of the head. Pull back slightly on the syringe to ensure you are not in a blood vessel. If there is blood, then slightly pull out and redirect the needle. Inject 5 ml of lidocaine into each side of the head as follows:
- 1.5 ml lidocaine at initial insertion spot
- Redirect the needle, insert 1.5 ml lidocaine
- Redirect the needle, insert 1 ml lidocaine
- As you withdraw the needle, insert 1 ml more lidocaine
Repeat for the other side of the head, wait about five to ten minutes before dehorning. The nerve block will be effective for about 90 minutes.
Using an inexpensive nerve block when hot iron dehorning calves makes the job much less painful for the calf, resulting in an easier task and a quicker recovery for the animal.
Source: Faith Cullens, Michigan State University Extension