Preventing Bull Accidents

(Updated June 2006)

by Temple Grandin, Colorado State University


The most dangerous dairy bull is a bull that has not been properly socialized to his own kind. When a young bull calf becomes mature at age two, he needs to challenge the top bull in the herd. If the bull calf has been raised alone and has not had the opportunity to interact with other cattle, he thinks he is a person and he wants to exert his dominance over the "herd". This can result in dangerous attacks on people.

Ed Price at the University of California found that bull calves raised in groups were much less likely to attack people than bull calves raised in individual pens. Bull calves raised on a cow were the least likely to attack. When they are raised with their own kind, they know who they are and they are less likely to think that people are part of the herd.

There is no such thing as a totally safe bull, but the risk of an attack can be reduced with proper management. When dairy calves are six to eight weeks old, they should be put in group pens. If there are no bull calves available for pen mates, a young bull should be raised with steer calves that are older and heavier. Any mature bull that charges a person, should be removed from a commercial dairy because he is too great a safety risk to the dairy personnel. To further reduce the danger, dairies that use bulls should consider raising bull calves on a nurse cow. Raising bull calves on a nurse cow will imprint them more strongly to their own kind and further reduce the tendency to attack.

Never play butting games with calves. It is cute when they are young but very dangerous when they grow up. Never allow a bull calf to push his head up against you. Tell him to get back. If you want to pet the calf, stroke him under the chin, on the rear, or on the withers (shoulder). Stroke him anywhere except the forehead. Pressure on this area will encourage butting.

The major causes of bull attacks are mistaken identity or improper behavior that has been learned. A bull will perform a broadside threat prior to attack. He will stand sideways so the person or other bull can see how big and powerful he is. Sometimes a person can make a bull back off by responding with the human variation of a broadside threat which for people is a frontal stance. Alternatively, the person may just back slowly away from the bull. NEVER RUN away and do not turn your back on him.

In dairies where bulls run loose in the cow pens, managers should be trained to notice aggressive postures. The bull should just move away along with other cows when the milkers approach. A bull that does a broadside threat to milkers should be culled. Even if a bull calf is reared properly with other cattle, an adult bull is usually safer if he spends most of his adult life penned with other animals. Bulls that are penned alone for long periods of time may be more likely to attack people. However, steers and heifers can be safely penned alone.

Understanding cow and bull behavior will help to reduce accidents. There is no way that cattle can be made perfectly safe, but the use of behavioral principles will reduce the risk. Attacks by bulls are the number one cause of fatalities which occur while handling livestock. Dairy bulls are often more dangerous than beef breeds. Castration of bull calves ata an early age will greatly reduce aggressive behavior.


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