Grooming behavior exposes the complex social lives of dairy cows

In a new study published by Frontiers, experts have gained new insight into the social networks of cattle based on their grooming behavior. The research may ultimately improve farm management practices and create healthier living environments for dairy cows.

An international team of scientists from the United States and Chile observed a small herd of dairy cows that had recently given birth. The experts wanted to gain a better understanding of the implications of social grooming behavior, which is also known as allogrooming.

In dairy production systems, cows are often shuffled around into different groups based on factors such as lactation stage, nutrition requirements, and breeding. 

As the cattle form new groups, they have to re-establish their social structure. Previous studies have shown that constant re-grouping causes negative effects on the behavior, health, and productivity of cows.

Allogrooming, which usually involves one cow licking another around the head and neck, is thought to serve a number of social purposes. For example, grooming improves social cohesion and establishes individual bonds among group members.

Study lead author Dr. Gustavo E. Monti is an expert in the Institute of Veterinary Preventive Medicine at the Austral University of Chile.

“Our aim was to understand how social networks are formed by cows after they are reunited at the beginning of the milking period, and what factors may influence these changes. This is important because cattle form strong bonds, which offer them social support and help them cope with the stressors that occur regularly in dairy cows’ lives,” said Dr. Monti.

Over the course of 30 days, the researchers recorded a total of 1,329 allogrooming events from 38 cows at a pasture-based dairy farm.

The team identified various patterns that were tied to specific attributes, such as a cow’s age or social rank. For example, they noted that cows were mutually cooperative, grooming individuals that had previously groomed them. 

The cows also tended to groom individuals of a similar age to theirs, which indicates they had a certain level of familiarity because they grew up together. In addition, older individuals groomed more cows than younger ones, suggesting that allogrooming could be related to seniority.

“Our results indicate that licking behavior is important to make friends and to maintain harmony in the herd. That older cows groom more individuals suggests that they take the role of ‘peacemakers’ in the herd,” said Dr. Monti.

“It is important for farmers to be mindful of the relevance of the social aspects of the lives of cows, animals that form complex emotional relationships within their group. Farmers should be aware that cows frequently grooming each other is a positive sign that means that those cows get along.”

“On the contrary, if social grooming declines, it may be a sign of impaired welfare. This new knowledge should be translated into innovative practical strategies that will result in the continued integration of cattle emotional and social needs into management systems.”

The study is published in the journal Frontiers in Veterinary Science.

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By Chrissy Sexton, Earth.com Staff Writer