Keeping livestock comfortable in the face of ever-changing and often adverse weather is a constant struggle. The more comfortable the animals, the more productive they'll be.

Researchers in North Wales are trying to understand how sheep shield themselves from cold, wet, windy weather. To do so, they've developed a pair of 'electric' sheep, models that look like sheep but are actually battery operated heating systems.

In a series of tests, scientists positioned the electric sheep in various farm locations and took their temperature, measuring the role trees, hedgerows and shelter belts play in blocking wind and rain.

"We're looking at how weather is experienced on a 'sheep scale' and although it's early days I've been really surprised by some measurements," Pip Jones, a PhD student at the University of Bangor, said in a news release. "Sheep use a substantial amount of energy just staying warm; and lose a lot of heat when it's cool, especially when there's a wind chill."

Researchers also measured the efficacy of shade trees during warmer months.

"On a hot day when the weather was around 30 degrees Celsius at the study site, we put a model sheep in direct sun, and the fleece recorded a temperature of 60 degrees Celsius, which is incredibly hot," Jones said. "This is where the shelter of trees could really contribute, creating shade in the summer and reducing the effects of wind-chill in winter."

Sheep must burn extra energy during cold weather to keep warm, which means they require more food. The models helped scientists calculate how much energy sheep must burn to keep warm while bunkering behind various shelter types.

"Tree-shelter from chilling wind could save energy and provide a real efficiency boost in the conversion of energy eaten to actual growth and health in our young livestock," Jones concluded.