Changing the diet of cows and sheep could reduce their greenhouse gas emissions, according to new research funded by Defra.
The study, which aims to help farmers cut their contribution to climate change, shows that feeding these animals foods such as maize silage, naked oats and higher sugar grasses can reduce the amount of methane they produce.
Agriculture Minister Jim Paice said:
“We are committed to supporting the farming industry as it faces the challenge of reducing its greenhouse gas emissions. 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 nine per cent of all UK greenhouse gas emissions and half of this comes from sheep, cows and goats. Recent figures show that farming accounts for 41 per cent of the UK’s overall methane emissions.
The new research, which was carried out by Reading University and the Institute of Biological, Environmental and Rural Sciences (IBERS), showed that it is nutritionally possible to reduce methane emissions and nitrogen excretion from cattle and sheep. For example:
- increasing the proportion of maize silage from 25 to 75 percent in a short-term trial was found to reduce methane emission per kg milk by six percent;
- high-sugar grasses could reduce an animal’s methane emissions by 20 per cent for every kilo of weight gain;
- naked oats could reduce methane emissions from sheep by 33 per cent; and
- crushed rapeseed could reduce methane production from dairy cows by 20 per cent per litre of milk produced.
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.