SEAWEED-BASED feed for sheep could be the part of the solution to the growing climate change challenges facing the farming industry.

Researchers have found that diets that contains small amounts of seaweed will reduce methane emissions which could hold the key to greener, more climate-friendly livestock farming.

In North Ronaldsay, Orkney, work began in 1832 to build a two metre-high dyke to keep the sheep from pasture that was needed for cows, since which time the flock’s diet has been restricted to seaweed foraged from the shore. They are one of only two groups of animals on Earth that exist purely on seaweed – the other is a marine iguana.

"People think seaweed isn't very nutritious, but you just have a look at them – they get pretty fat on it, especially in winter when there's lots of fresh seaweed washed up," said sheep farmer Alison Duncan, who runs the Bird Observatory. "And the lambs have a pretty good life – we don't send them for slaughter until they're three or four years old.”

This is becoming more worldwide with studies from the US, New Zealand and Australia having shown that livestock with some seaweed in their diets produce far less methane than animals fed on grass or general feed. Since methane is a greenhouse gas that has a warming effect almost 30 times as powerful as that of carbon dioxide, the solely seaweed-eating North Ronaldsay sheep could provide an answer to greener farming.

Davidson’s Animal Feeds specialist, David Beattie, is studying the protein-rich seaweed diet to try and bring it into general livestock feed, in a three-year programme working between the factory floor at Davidson’s feed mill in Shotts and his laboratory at James Hutton Institute in Dundee. He commented:"You'd be amazed how picky animals are about their food. We have to put molasses into the mix to get the animals to eat it – otherwise they just pick out the bits they like and leave the rest. So, it's quite a task to introduce seaweed into the feed and to make sure it's still protein-rich and of top quality."

David's experiments have shown that carbon dioxide as well as methane emissions are lowered when seaweed is introduced into feed. If he succeeds in creating a nutritious seaweed blend that's palatable to ordinary livestock, there would be other environmental benefits too, including being able to source more animal feed locally and sustainably.

"A large proportion of the ingredients we put into animal feeds in the UK at the moment are sourced from across the world, like oil seed from South America," he continued. "This clearly has negative implications for the environment both in terms of farming methods to harvest that crop but also in terms of transportation. If we could identify a seaweed variant that could substitute oilseed, it would have a huge environmental benefit."

Mr Beattie hopes that his research will help Scotland to re-establish commercial seaweed farming, creating jobs and revitalising coastal towns.