Source: University of British Columbia
Dairy cattle undergo personality changes during puberty much like humans do, according to new UBC research published this week in the Royal Society Open Science. While cattle’s personality traits are distinct and consistent at a young age and during adulthood, that isn’t the case during puberty.
Researchers from the Animal Welfare Program in UBC’s Faculty of Land and Food Systems conducted the long-term study to understand the development and stability of personality traits over dairy cattle’s lifetime. It is the first study of its kind in a farm animal species. We spoke with Professor Marina von Keyserlingk, the study’s senior author, about the findings.
How did you study personality of dairy cattle?
A way that we commonly test for personality in farm animals is to expose them individually to new situations and record their behaviour. These tests include a novel environment, a novel human and a novel object. Different individuals will react in different ways. For instance, some calves and cows will immediately approach and investigate the object or human, or explore the new environment, while others will never touch the object or human and stand still for the duration of the test. We interpret the collection of these behaviours as reflecting two key personality traits: bold and exploratory.
Did animals have the same personality as adults as they did when they were calves?
We found that cattle were consistently ‘bold’ or ‘exploratory’ in the early rearing period, from birth to about three months of age. During the later period of development, from about one year to 2.5 years of age, cattle also consistently showed these traits. However, the study showed that during puberty when calves reached sexual maturity, there appeared to be a change in personality. This means that dairy cattle show consistent personality as calves and adults, but with a period of inconsistency around puberty. This phenomenon is similar to that seen in humans, where teenagers often will express different personalities to that of when they were younger, and may again express different personalities when they grow up. These changes in personality around puberty are also seen in squid, fish, junglefowl, and mammals like hamsters and mice.
Why might personality change around this time?
Major changes in the body at this stage of development may contribute to this, such as changing hormone profiles and growth rate. Changes in the environment may also contribute. In the case of dairy cattle, they are often mixed with new animals, or are placed in new pens and have to learn how to use new feeding equipment.
How can this knowledge benefit dairy cattle?
The reactions of the calves and cows to our novel test situations likely reflects how they will react to actual novel or stressful events on the farm. In an earlier study we conducted, exploratory calves in these test situations were seen to eat more and gain more weight. Other studies have found that cows that are more fearful of humans ate less and produced less milk. These findings are important because they show that personality traits can be a useful indication of which animals will be most (or least) productive on the farm at different life stages. Farmers could potentially identify calves and cows on the basis of personality who are likely to do well or poorly when faced with stressful farm-management practices.