The electrical activity of a horse’s brain can reflect their welfare state, researchers in France have found.
The recently reported findings open the door to the possibility of objectively assessing the welfare state of individual horses using the results of electroencephalograms (EEGs).
The research at the University of Rennes involved 18 horses. Half lived in individual stables, while the other half were kept at pasture.
The study employed a headset developed for horses by university neurophysicist Hugo Cousillas, which can take an EEG using four electrodes. The headset can transmit the readings to a nearby recording device.
The study team, whose findings have been described in the journal Applied Animal Behaviour Science, found marked differences between the stabled and pastured horses in a resting state.
They found that individual EEG profiles were associated with different welfare scores among the horses.
Horses assessed as having a good welfare state produce fewer gamma waves in the right hemisphere.
Theta waves production correlated undesirable stereotypic behaviours which can be a sign of compromised welfare.
The researchers, Mathilde Stomp, Martine Hausberger, Séverine Henry, Serenella d’Ingeo and Cousillas, acknowledge the challenges in assessing the cognitive and emotional status of a horse in terms of its welfare.
However, the resting state EEG emerged as a reliable tool for assessing animal welfare.
The results showed clear individual differences in the proportions of the different waves and their inter-hemispheric distribution, they said.
“Three different EEG power spectrum profiles were highlighted, from a bilateral predominance of theta waves in horses in a more positive welfare state to a bilateral predominance of beta waves in horses with clear expressions of compromised welfare,” they reported.
“It seems that bilateral but also left-hemisphere theta activity is a promising neurophysiological marker of good welfare in horses, while a bilateral or RH high production of gamma waves should alert about potential welfare alterations.”
Brain activity reflects (chronic) welfare state: Evidence from individual electroencephalography profiles in an animal model
M. Stompa, S. d’Ingeo, S.Henry, H. Cousillas, M.Hausberger