It's a project that aims to give meat eaters a little peace of mind when they sit down for dinner.

Experts are working to assess the “emotional expressivity” of livestock in the supermarket supply chain in a bid to identify those that lived happier lives.

It comes amid a growing emphasis on the welfare of animals destined for slaughter and concern over the environmental impact of meat consumption.

Researchers from Scotland’s Rural College (SRUC) say they want to focus on “recognising and promoting positive expressions of animals’ welfare and quality of life”.

Animal behaviouralist Professor Francoise Wemelsfelder has begun working with Waitrose’s Animal Welfare Development Group - an expert panel hoping to achieve the best quality of life they can for farm animals supplying the chain’s produce.

A key part of the project is the Qualitative Behavioural Assessment (QBA).

The system, developed by Ms Wemelsfelder, focuses on expressive “body language” which animals display when they interact with each other and their environment.

It then integrates observations into a framework that can offer real insight into an animal’s emotional state.

Describing the new approach, Ms Wemelsfelder said: “For any given species, you need a list of about 20 terms to describe both the positive and negative aspects of the animals’ emotional range.

“Is the animal relaxed, playful, confident or curious? Is it tense, frustrated, agitated or bored?

“Then you scale the intensity of this expressivity.

“It’s bored? Well, how bored? It’s content? How content? “The scale starts at zero for ‘not at all content’ and goes up to ten for ‘couldn’t be more content’.”

Scoring a significant number of terms in this way allows patterns to emerge that give an indication of the animal’s general mood.

“It’s the integration of individual assessments into the framework that makes the science robust,” she said.

“It can become a sharp tool for measuring something quite subtle.

“But as with any method, you need to provide sufficient support and training to make sure the system functions well.”

Ms Wemelsfelder and the Animal Welfare Development Group will be working with supply chain team leaders and farmers to devise lists of descriptors for dairy cows, pigs, laying hens, chickens, veal calves and ducks, with these being converted into a toolkit app.

The Waitrose & Partners field team, which visits farms regularly to ensure welfare standards remain high, will then have an on-the-go way of monitoring the emotional state of animals.

“There is so much knowledge among the farmers already about the way animals express themselves, but a lot of it is implicit and goes unspoken,” said Ms Wemelsfelder.

“The toolkit will formalise this and give people confidence to say, ‘Let’s do something with the knowledge that we have.’”

Andrew Booth, who chairs the Development Group, said: “We know that Waitrose & Partners has always led the way when it comes to animal welfare, but what we wanted was to create a framework to assess this welfare, to show what we’re doing well and to identify areas for improvement.”

John Gregson, a member of Waitrose & Partners’ CSR and Agriculture team, added: “If people in our society are going to continue eating meat, then we’re probably going to eat a bit less of it.

“But I think we can aspire to eat better meat - and that’s meat from an animal that has been raised well, with its wellbeing in mind.

“Who wouldn’t want that?”

Colin MacEwan, SRUC’s Commercial Director, said: “Having access to a superb supply chain with quality suppliers gives our researchers an excellent opportunity to grow our relationship and continue to build a lasting partnership that will allow both Waitrose and SRUC to explore further innovative industry-led research.”

Although plant-based protein options are increasing in popularity, global meat consumption is still growing strongly.

It is expected to increase 1.4 percent per year through to 2023, according to recent data from Packaged Facts, a division of MarketResearch.com.