Electric fences are used in paddocks up and down the land, but what effect do they have on equine stress levels?

The answer, according to a new Swiss study, is none.

The experiment, led by Rupert Bruckmaier of the University of Bern and published in the journal, Applied Animal Behaviour, measured stress responses in 20 horses between the ages of six and 18 years kept in four different grass outdoor enclosures.

The arenas were of two different sizes — one of each size had wooden fencing, the other had electric fencing.

The smaller of the two sizes was 12.25m2 — the size of a modest stable — and the larger enclosure was nearly three times that size, at 36m2. The horses were systematically rotated between the four enclosures, spending 90 minutes in each one.

The researchers videoed the horses to check for behavioural signs that might indicate stress and to determine whether there were any differences in the way horses grazed in the various paddocks. Measurements were also taken of the animals’ heart rate and heart-rate variability, and samples of saliva were obtained for cortisol analysis — all of which indicate stress response.

“The total amount of stress-indicating behaviour did not differ between the two fence types, and it did not matter whether the enclosed area was large or small,” reported Mr Bruckmaier and his team.

But the study did reveal that horses made less use of the available space, and moved around less, in the electrically fenced enclosures and in the smaller of the wooden-fenced areas. They were also less likely to roll in the small paddocks.

Kent-based livery yard owner Sue Wright has five paddocks which are electrically fenced, and said that the results of the study were “reassuring”.

“I use electric fencing because it’s convenient, and although I’ve never had an issue with it, it’s good to know that it doesn’t have an effect on horses,” she told H&H. “I think paddock size is more of an issue — horses that have a decent amount of space to move around in are generally much happier.”