Reduced green house gas emissions by change in diet
Researchers at Reading University and the Institute of Biological, Environmental and Rural Sciences have found that dairy cows could emit 20% less methane for every litre of milk if they are fed crushed rapeseed.
Increasing the proportion of maize silage in cows' diets from 25% to 75% could reduce methane emission by 6% per litre of milk, while high-sugar grasses could reduce an animal's methane emissions by 20% for every kilo of weight gain. And a diet including a particular variety of oat could cut sheep's methane emissions by a third, the researchers said.
UK Agriculture minister Jim Paice said: "It is very exciting that this new research has discovered that by simply changing the way we feed farm animals we have the potential to make a big difference to the environment."
Agriculture contributes about 9% of all UK greenhouse gas emissions, according to the Department of Agriculture, Food and Rural Affairs (Defra), with half of this coming from sheep, cows and goats.
Farming has been shown to account for 41% of the UK's overall methane emissions.
A Defra spokesman added: "In the longer term the benefits gained by changing animals' diets will need to be considered against other environmental impacts as well as how practical or costly they are for the farming industry to implement."
It is also not clear whether these measures actually reduce emissions from the animals, or whether the dietary changes increases the overall yield therefore reducing the proportion of methane produced per kilo of meat or litre of milk.
University of Reading