An observational study of a group of dairy cows has revealed that they exist in complex social networks that change when they get moved into new groups. Published in the journal Frontiers in Veterinary Science, the research highlights the importance of preserving the social lives of these animals to improve their quality of life and offers insights to inform better farm management practices to best care for them.

The researchers from Chile and the United States spent 30 days with a group of cows who had recently given birth. They were looking out for grooming behaviors, known among cows as allogrooming, to indicate which animals had established a relationship. The study was the first of its kind to employ the stochastic actor-oriented modeling (SAOM) statistical monitoring model to a mammal other than humans. The SAOM framework creates a map of changing relationships within a social group based on data describing individual attributes and group dynamics over time.

Dairy cows are constantly reshuffled in modern-day farming as animals are siphoned off into groups dependent on their needs, be it diet type or breeding stage. Each time a cow is moved from one group to another, they are forced to establish new friendships and find their social footing all over again, which is known to have negative consequences for both their physical and mental health, as well as their productivity as dairy cows.

The team's findings showed that multiple factors were taken into account when cows selected new allogrooming partners, such as social rank or if the cows had partaken in allogrooming in the past. The dairy cows also appeared to favor animals of a similar age, which probably indicates familiarity as the cows would have grown up together. The most active groomers in the group actually received the least attention from other animals throughout the 30 days, with younger animals practicing less allogrooming than more senior members.

"Our results indicate that licking behavior is important to make friends and to maintain harmony in the herd,” said Dr Gustavo E. Monti, lead author on the study from the Institute of Veterinary Preventive Medicine at the Austral University of Chile, in a statement. “That older cows groom more individuals suggests that they take the role of 'peacemakers' in the herd.”

"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," added 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. 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.”