New technology could help tackle lameness in sheep by providing farmers with an early warning of a developing problem in their flocks, researchers have found.
More than 90% of UK farmers report lameness in their sheep and the condition costs the sector about £80m a year. Much of the issue is due to foot rot caused by a bacterial infection.
The key is to spot the disease early to prevent it spreading and becoming a major, costly health and welfare problem for the whole flock.
However, researchers at the University of Nottingham found that making an accurate diagnosis was being hampered by the sheep’s instinctive behaviour.
As sheep are a “prey” species they are likely to mask signs of lameness that might identify them to a predator as an easier kill. The behaviour pattern is repeated when they feel threatened by the presence of observing farmers and vets.
Early diagnosis hard to detect
This means that, until now, early diagnosis has been difficult and reliant on close visual inspection, a spokesman for the university said.
However, the researchers have developed and tested an automated lameness detection system that identifies the modified behaviour in the sheep when standing, lying and walking.
The prototype technology is based on a tagging and monitoring system developed by Nottingham associate professor Jasmeet Kaler, in conjunction with computer hardware giant Intel and software developer Farm Wizard.
Dr Kaler explains that the smart, wearable technology, consisting of a sensing device worn on the sheep’s ear tag, gathered accelerometer and gyroscope data.
How it works
The tag effectively tracks the animal’s behaviour and movement, and its way of walking, standing and lying.
Software algorithms then create different alerts for farmers. For each of the three activities (standing, walking and lying), the study identified features that differed between lame and non-lame sheep.
This is particularly novel in the cases of lying down and standing, which have less obvious lameness-related behaviours that had been difficult to spot with the human eye previously.
The results suggest that instead of lameness affecting activity levels of sheep, they carry out activities differently, leading to a change in acceleration and rotational movement.
For example, lame sheep showed a change in gait, with peculiar head nodding in line with stride, compared with non-lame sheep which had a smoother stride pattern.
A particularly interesting find was that lame sheep could be spotted with higher accuracy when lying and standing.
Differences were recorded in the variability and smoothness of movements for both standing and lying down.
Lame sheep redistributed their body weight to an unaffected leg, leading to postural changes when standing. The research also suggests that lame sheep may lie differently than non-lame ones, which again could be due to the animal attempting to alleviate the pain.
Dr Kaler added: “Our study has shown conclusively that there are behavioural differences between lame and non-lame sheep when walking, standing and lying.
“This has been the first report of its kind and, given that lameness classification is possible within all these activities, this helps to improve the accuracy as well as flexibility in terms of energy requirements.”
He added: “This automated system for lameness detection can help improve sheep health and welfare on farms.”