On commercial farms, it’s common practice to prevent horns from developing by burning the horn buds with a hot iron. Even when pain control is applied, it’s highly likely that they experience significant pain in the hours and days following the procedure. However, asking how calves feel after disbudding is challenging, especially because they may have evolved to hide their pain.

What does calf play say about pain?

Imagine a group of preschoolers in the playground; you might see some playing tag, while others are rough-and-tumble wrestling. Calves are the same – they run alone, they run together, they jump, they kick, and they play-fight.  One way to ask a calf about pain is to observe their play, assuming that the less they play, the worse they feel.

In this study, after disbudding, the calves kept running around, but play-fighting was almost eliminated over the next 7 days. Why? Looking at how calves play-fight, this makes sense – calves might avoid banging heads if the disbudding injury is still painful even about 7 days post-disbudding. Or perhaps it hurt once, and they become afraid of play-fighting altogether.

Is the bucket of milk half empty?

So, calves feel pain after disbudding, but just like people, they likely all handle it differently. This can be related to whether your glass (or bucket of milk) is half full or half empty. Like humans, more pessimistic calves may expect pain to be worse and end up experiencing it more negatively.

All calves, whether pessimist or optimist, stopped play-fighting after disbudding. On the other hand, most of them actually ran around more than before on the day after disbudding, potentially to make up for the lost play-fighting or to cope with stress. But what about the pessimistic ones? They didn’t show quite the same increase in running, suggesting they weren’t recovering in the same way or not at the same pace.

Next steps?

Implication 1: Better or longer pain relief needs to be explored for calves after disbudding.

If calves don’t play-fight for up to a week after disbudding, this likely tells us that they need better pain relief. Unlike us, they can’t reach for paracetamol themselves, so more research is needed on the best schedules of pain treatment to ensure they are free from pain and can play with their friends.

Implication 2: More pessimistic calves may have worse or longer-lasting experiences of pain

It’s easy to accept that “one size doesn’t fit all” for humans, and this idea needs to be extended to non-human animals like calves. We need to better understand how each calf experiences pain so that we can tailor their care to them, much like we would try to do with patients in a hospital.

Interested in the interplay between pain, play, and pessimism in calves? Read the full paper here.