Farming Magazine - June, 2009

COLUMNS

Beef: Castration of Male Calves

I once did a projection of the value of castration in beef calves based on the difference in price of weaned bull calves versus weaned steer calves. Allowing a time cost of two minutes to castrate a calf—easily done with a little practice—I found castration was a job that paid $3,000 per hour! There is an ongoing discussion about the timing, method and necessity of castrating bulls for beef production. I would like to tackle the last point first.

The fundamental reason we castrate male calves for beef production in the U.S, is because of the grading system in place. Under the U.S. system, there is a “bullock” and not a Choice carcass. In this case, it usually becomes a “no roll” at a significantly lower value. Small retail meat markets often take advantage of the lower price and leaner composition of bull beef to add to their meat case. Market reports will occasionally show young beef bulls in southeastern Pennsylvania will sell equal to or above Choice steers for this reason. A second main reason we castrate male calves is because of the beef production system. Cattle are commingled from many farms and ranches numerous times between weaning and harvest. The commingling of bulls will result in fighting and injury because of the need to establish dominance in the group. The stress associated with this fighting at or near harvest will contribute to “dark cutters” as beef, and seriously reduce the value of the carcass. Producers in Europe have no distinction of bull or steer beef in their grading system, so bulls are often finished for harvest. The major difference, however, is that most beef producers retain ownership of their beef cattle through harvest, and the bulls are not commingled with those from other farms.

There are several methods available to castrate male calves. These include small rubber bands, surgical removal of the testes, crimping the scrotum to destroy the blood supply, and large bands used on older bulls. It has been my position as an educator that the most desirable way to castrate cattle is with a knife. This is for several reasons. First, there is no question the castration will be complete. Secondly, we have some unpublished data from dairy-beef production that indicates knife castration may be the best method for the overall welfare of the calf. Our data indicated castration with small rubber bands induced a high body temperature for an average of nine days, and a delay in feed intake for up to five days. The calves cut with a knife in the same environment did not experience high body temperatures and had returned to normal feed intake within 48 hours. Follow-up data showed calves castrated with small rubber bands had an 8 percent failure rate of complete castration. For these reasons, I still consider small rubber bands to be undesirable as a method to castrate calves.

The timing of castration is also an issue. We know bull calves will typically grow faster to weaning than steer calves. Therefore, some producers wait to castrate bulls to capture this additional weight. Oklahoma workers (Lents, et al.) reported from a study where at two to three months of age, bulls were randomly assigned to one of three treatments: banded, surgically castrated or intact. All calves were implanted with 36 mg of zeranol (Ralgroâ) at treatment. Calves were weighed at treatment and at weaning (seven to eight months of age). Weight gain from treatment to weaning was not influenced by treatment. This result indicated knife castration at an early age (from one day to two months of age) may not alter preweaning performance. Further, bulls castrated at weaning with large rubber bans were compared. Treatment tended to alter weight gain during the 50 days after weaning. Bulls that were banded at weaning gained less weight than bulls that were banded or surgically castrated at two to three months of age. Another report of Arkansas work (B. Hicks) compared cattle castrated at weaning and shipment. Bull calves were castrated by banding or surgical methods on day zero or 14 of the receiving period. Over the 43 to 52-day trials, bulls castrated surgically on day zero gained significantly faster (1.45 pounds per day) than bulls castrated surgically on day 14 (1.12 pounds per day) or banded on day zero (1.21 pounds per day) with bulls banded on day 14 having intermediate gains (1.36 pounds per day). No differences in morbidity were observed among the castration treatments. Steers gained faster than bulls (1.78 versus 1.28 pounds per day) and had a lower incidence of morbidity than bulls (50 versus 79 percent).

As with any invasive procedure to animals, common sense about cleanliness and care is important. With small rubber bands, there is a potential for the bands to break. If this occurs from one to three weeks after application, it can cause the calf to die from toxemia. Be sure the bands are in excellent condition and are applied correctly (both testicles completely below the band). Crimping, or “pinching,” older bull calves will fail to produce castration if the instrument is not placed in the scrotum correctly or is not operated correctly. It is usually recommended to crimp both sides of the scrotum at least once. When using a knife, get some instruction and know what you are doing. We include knife castration as part of the training in our Youth Cow Camps, and the people often comment that the procedure is easier to do than the rubber bands they used at home. Make sure the calf has a dry place to be for at least 24 hours after castration. Observe recently-castrated calves for any signs of fever or lack of mobility. For knife castration, drainage should stop within a few minutes, and there should be very little blood coming from the wound. Use an antiseptic treatment on a knife or scalpel between animals. Fly control is important in the first three days after castration. When using the large bands on older calves, follow the directions for their use closely, including giving tetanus shots as directed by the manufacturer.

Make the job of castration easy on yourself and the calf by doing it in a timely and correct way.

Dr. John Comerford is associate professor of dairy and animal science at the Pennsylvania State University.