Almost all animal industries utilize routine management procedures that cause pain. Procedures such as castration, tail docking, branding, dehorning and beak trimming all subject our food animals to, what we believe to be, short-term pain for long-term benefits.
There is little argument that the procedures are important. However, the controversy arises when we discuss how and when they should be carried out.
As a researcher, I do not believe we should be investigating the relative impact of dehorning techniques when we could easily render them all unnecessary. The least painful procedure and the one that causes the least setback in growth is to remove horns by genetically selecting for polledness.
In cattle, horns are inherited as an autosomal recessive gene, polledness being dominant. In one breeding season, a producer can take a herd of horned cows and breed them to a polled bull (homozygous for the polled condition1) and have an entire polled calf crop.
Why Worry About Horns? When horns are left on feedlot cattle, the amount of bruised trim from the carcasses has been reported to be twice that from an equivalent hornless group. The industry's desire to produce a consistently high quality product is compromised by allowing cattle to enter our feedlots with horns.
If we dehorn cattle upon arrival at the feedlot, studies have shown the setback in gain can be detected for up to 106 days post dehorning. The bruising and dehorning studies suggest that horns should be removed sometime before cattle reach the feedlot.
Even for breeding stock, keeping horns on cattle comes at a price. If cattle have horns, it makes every competitive encounter at the feed bunk, hay bale, shade tree, water trough, etc., potentially more dangerous.
Some producers tell me they prefer certain horned breeds because they are superior to their polled counterparts.
In 1996, Dr. Laki Goonewardene from Alberta and I collaborated on a project to compare the performance records of horned and polled Charolais and Hereford bulls. The bulls were kept at two test stations, one in Alberta and one in Saskatchewan from 1985-1993. We had access to the performance records of 578 Charolais bulls (329 horned and 249 polled) and 1,860 Hereford bulls (1,182 horned and 678 polled).
As shown in Table 1, we found very little difference between the horned and polled bulls in the traits that were measured. The polled Charolais bulls did carry significantly more backfat than their horned counterparts, but they were not different in average daily gain, adjusted yearling weight or in scrotal circumference.
The polled Hereford bulls in Saskatchewan had a significantly higher average daily gain compared to the horned bulls and tended to be larger yearlings. Polled Hereford bulls in Alberta also tended to have a greater average daily gain, but the difference was not considered significant.
Our findings were similar to other studies. Research by Lange in 1989 found no difference between polled and horned German Simmental cattle in growth, carcass yield, carcass composition, health and reproductive performance.
Work reported by Frisch and coworkers from Australia in 1980 - comparing various beef breeds - showed no difference between horned and polled crossbred lines in live weight, fertility and mortality rates.
Another encouraging finding was that the ratio of polled bulls at each Canadian test station over the time period had gradually increased as the number of horned bulls decreased. In other words, good polled bulls are becoming more readily available.
Historically, polled beef bulls may have been inferior, but there is no evidence that overall differences still exist today. Dehorning beef cattle via genetics is a welfare friendly practice that everyone in the industry should embrace and support.
Joseph Stookey is an associate professor at the Western College of Veterinary Medicine, University of Saskatchewan. Contact him at firstname.lastname@example.org.
1Homozygous for the polled condition refers to a bull carrying two copies of the polled gene. Because the polled condition is a dominant trait, some polled bulls can be heterozygous and carry one copy of the polled gene and one copy of the horned gene. Heterozygous polled bulls will on average pass on the horned gene to half of their progeny. If horned cows were mated to a polled bull with the heterozygous condition, on average we would expect 50% of the calves to be horned. Scurs, which are horn-like, are controlled by a different set of genes and can occur on polled bulls.