Grooming and the social lives of cows

Cows, it seems, are more complex creatures than we thought.

Earlier this year, Cosmos reported on the mood swings teenagers can experience during puberty, and now we’ve learned that their parents indulge in a little social grooming.

A team of Chilean and US scientists kept a close eye on a herd of 38 dairy cows for a month and observed 1329 grooming events and a variety of patterns in interactions based on age and social rank.

They hope their findings, reported in a paper in the journal Frontiers of Veterinary Science, can influence farm management practices, bringing them more in line with cows’ natural social behaviour.

“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,” says lead author Gustavo E Monti from the Institute of Veterinary Preventive Medicine at Chile’s Austral University.

“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.”

Allogrooming, as it is known, is common in many species and is particularly associated with primates. In cows, it involves licking around the neck and head and is believed to establish bonds between members and enhance the overall cohesion in the herd.

The researchers found that cows tend to groom others of a similar age – suggesting that growing up together enhances social grooming – and to stick with individuals that had previously groomed them, suggesting mutual cooperation.

The most active groomers that did not seem to prefer specific individuals actually received less attention from other group members over time, and older individuals groomed more cows than younger ones, suggesting that allogrooming could be related to seniority in the herd.

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

The researchers say that cows are constantly moved between herds in modern dairy production systems and so must re-establish social structure, which can have negative impacts on behaviour, health and productivity.

“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,” says Monti.

“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.”