Adding the stems, seeds and skins from wine grapes to a dairy cow's feed boosts milk production by 5% and cuts methane emissions by 20%, according to research conducted by Australian scientists.

"We've managed to utilize what is currently a waste product for the wine industry and turn it into a very valuable feed source," said scientist Peter Moate. The data also showed an increase in healthy fatty acids in the milk, six times higher than with standard autumn feed. "These particular fatty acids are extremely potent in their ability to benefit heart health and are also known to help fight cancer, diabetes and arthritis," said Moate.

The research is part of a wider program looking at the use of feed supplements to reduce methane emissions. Other possibilities have included brewers' grains and cold-pressed canola meal.