German-born scientist Mirjam Guesgen lived in New Zealand for 15 years before she got anywhere near a sheep. Her PhD zoology research brought her closer than most ever get to the ubiquitous woolly ruminant, leading her to new understandings of pain expression and empathy.
Exploring the extent to which farm livestock experience pain and empathy might be contentious in a nation that depends on farming, slaughtering, devouring and exporting them for economic livelihood.
Dr Guesgen’s interest in the topic was sparked by her curiosity about broader questions on the evolutionary role of pain expression, and whether animals respond to pain they witness in others of their species. Being social animals, sheep seemed an ideal species on which to focus.
The Lamb Grimace Scale is one of the results of her investigation, providing a visual guide to facial expressions that denote pain in sheep. They include ear, nose and mouth positions as well as cheek flatness. She has also found that lambs can empathise – they appear to imitate expressions of pain by flattening their ears and looking at their own tails when in the presence of other lambs being docked.
A meat-eater, this “city-slicker” who moved from Auckland’s North Shore to Manawatu- for her project believes it is important to deepen our knowledge of animal behaviour – including their experience of pain – in the interests of animal welfare and a more humane farming industry.
Dr Guesgen learned how to dock lambs’ tails for the three-phase experimental part of her study. Docking is a regular procedure and provided a suitable basis for investigating aspects of animal behaviour that could contribute to improving pain management for the country’s 31 million sheep, she says.
In New Zealand docking is done with either a constrictive rubber ring, which causes the tail to drop off, or cauterisation with a hot iron. The former method induces mild or moderate pain that lasts a few hours, while pain with the latter is much shorter but more intense. Guesgen and her volunteers opted for the rubber ring option to be able to record behaviour over time.
If the tail is left intact, faecal matter – or dags – builds up on the tail and hindquarters. This results in fly strike and wool maggots, which eat into the flesh causing greater pain and distress.
Her work also involved observing, filming, photographing and describing the behaviour of “actor” lambs (those undergoing docking), and “observer” lambs.
She compared reactions across various combinations to see whether pain expression and empathy varied according to the relationship between “actor” and “observer”, in terms of familiarity, relatedness, sex and whether the observer animal had experienced pain itself.
Her discovery that “observer” lambs experience empathy “at a primal level” by displaying what is known as socially facilitated behaviour when seeing its own kind express pain is a first.
Creating the Lamb Grimace Scale and working with leading animal welfare scientists, both at Massey and around the world, were her research highlights. “I learned so much from them and am so grateful for their expertise.
“Fifty years ago, people said animals can’t feel pain,” says Dr Guesgen. “Things have come a long way since then, and the more we know about their emotional lives, the more we can do to minimise the impacts of what we do to them.”