You might think that every cow in a herd is the same, but a UBC study suggests some cows are sadder than others.
Animal welfare researchers trained a group of 22 calves to expect that a bottle placed in a hole on one side of the room would contain milk, while one placed on the opposite side would only blow a puff of air into the calves’ muzzles.
Then, the researches placed a bottle in a hole between the ‘good’ and ‘bad’ bottles and watched to see which calves were willing to try and see if it had milk.
The researchers believed that the most optimistic calves would approach the new bottle even if it was placed near the empty bottle, while the pessimistic cows would avoid it in fear of getting the puff of air.
They found that although the calves all had different responses, each individual calf consistently made the same choice to either try or avoid the new bottle.
The calves varied in their responses, but individual calves remained consistent and made similar choices even three weeks apart. Researchers concluded that pessimism was a consistent individual trait, not just the result of temporary moods or emotions.
“Sometimes we are tempted to see only the herd, even though this herd consists of different individuals who cope differently with stressful events,” said PhD candidate Marina von Keyserlingk.
“It’s important to consider the individual’s perspective, because even if conditions are good on average, some animals may still suffer.”
Pessimistic cows were also more scared overall, the study suggests.
“Calves that were more fearful were also more likely to view the glass as half empty,” said von Keyserlingk.
The team will go on to study how farmers can ensure even the sad cows have happy lives.