What do we know about cow 'friendship'?
Published in Dairy Star May 9, 2009
In previous articles, we discussed the importance of providing cows a comfortable environment and optimal management so they can express their genetic potential for milk production, stay healthy, increase their longevity, reproduce, etc., or in a nutshell, be more efficient, profitable and content. A comfortable cow is a cash cow.
The public is demanding that we pay more attention to animal well-being. One of the concerns includes the expression of natural behaviors. Are cows being provided an environment where they can be ‘cows’? One challenge is that we don’t know enough yet about how cows see the world and what is important to them.
Recent research on animal behavior looked at the social interactions between cows in confinement systems. When we overcrowd them in a freestall barn, or we keep them tied to a stall, are we affecting their social level of comfort? What is important to them? Are all cows within a pen similarly ranked or is there a hierarchy? We learned years ago that there is a hierarchy, but how does it work? Can it affect their feeding behavior or access to feed? The answer is probably ‘yes’.
A recent study in Edinburgh, UK, investigated how low ranking animals reacted to the presence of a dominant cow in their feeding area. A “Y-maze choice test” was used. Initially, cows were trained to choose between two options: low or high quality feed placed in separate bins of different colors. Half of the cows were offered high quality feed in black bins and low quality feed in white bins, and the other half was offered the opposite to prevent color bias. Social status of each cow was also assessed at the feed bunk, pairing a dominant cow with a subordinate cow for the next set of tests. After the researchers were sure that the cows learned how to identify feed quality, the cows proceeded to choice test 2, where a subordinate cow was offered two bins of high quality feed, one of which had a dominant cow feeding from it. Cows showed a significant preference for feeding alone rather than next to a dominant cow. In choice test 3, a subordinate cow was offered a high quality feed bin with a dominant cow feeding from it, or a low quality feed bin alone. Again, majority of cows chose to eat alone, trading off feed quality with feeding next to a dominant cow. Authors suggested that social status within a herd could affect feeding behavior, especially in situations of high competition and for subordinate cows. When looking at the average production in a pen of overcrowded cows, we might be missing what is happening to these less dominant animals. Each cow is important. Feeding options that allow all animals to eat a well balanced diet should be the goal when building, stocking and managing dairy facilities.
Another interesting aspect of social behavior is social licking or “allogrooming.” A recent study in British Columbia, Canada, described this socio-positive behavior in group-housed dairy cows as related to social dominance, friendship, parity, and level of competition at the feed bunk. The researchers increased competition at the feed bunk by blocking off half of the feed bunk space. Cows groomed each other mostly at the feed bunk right after fresh feed delivery or in the middle of the night (between 12 and 2 a.m.). A cow’s body was divided into various areas (Figure 1) and it was observed that most of the allogrooming was performed on the neck and head, sites that the cows can’t reach on themselves. They also noticed most of the events (74%) at the feeder rather than in the alleys and stalls, even though cows spent less time during the day at the feeder than in the stalls. The authors suggested that allogrooming probably has a role in helping with haircoat hygiene and in reducing tension between animals, and it may be an indication of friendship in cows. They noticed that there were preferential associations between certain pairs at the feeders. It was also interesting that the pairs not only groomed each other more, but also displaced each other more at the feed bunk. It was as if they were taking their turn at the feeder and because they were grooming each other (friends?), it was acceptable to give each other the space. All cows, dominant or subordinate, expressed allogrooming. However, when competition increased by reducing bunk space, allogrooming declined, especially in subordinate, first-calf heifers. Heifers could be less dominant and more susceptible to have less socio-positive interactions in competitive situations, such as overcrowding, especially if mixed with older, more dominant cows that can cope better in those situations. Keeping heifers separate from older cows would help them have a better social environment and be more productive.
Figure1. Percentage of time spent allogrooming for different parts of the cow's body. (from: Val-Laillet et al., 2009, Applied Animal Behavior Science©)