Working a bit like an antibiotic, the spices were found to kill the methane-producing 'bad' bacteria in the animal's gut even as the 'good' bacteria continued to flourish.
The findings are part of a study by Newcastle University research student Mohammad Mehedi Hasan and Dr Abdul Shakoor Chaudhry.
"Spices have long been used safely by humans to kill bacteria and treat a variety of ailments - coriander seeds, for example, are often prescribed for stomach complaints while turmeric and cloves are strong antiseptics," The Telegraph quoted Hasan, as saying.
He added: "Methane is a major contributor to global warming and the slow digestive system of ruminant animals such as cows and sheep makes them a key producer of the gas."
"What my research found was that certain spices contain properties which make this digestive process more efficient so producing less waste - in this case, methane."
The Newcastle study analysed the effects of five curry spices - cumin, coriander, clove, turmeric and cinnamon.
Each was "ground up" - as if chewed by the sheep - and added to an in-vitro solution mimicking that found in the rumen of a sheep.
The level of methane released by each was measured against a control.
Coriander was found to be most effective, reducing methane production from 14ml/gram of "food" to 8ml/g - a drop of 40 per cent.
Turmeric produced a 30 per cent reduction and cumin 22 per cent.
Chemical analysis undertaken during the research suggests the high levels of unsaturated fatty acids found in coriander seeds are likely to be responsible for the large reduction in methane gas.
Project supervisor Dr Chaudhry said: "The rumen fluid in cows and sheep is very similar so we would expect to see an equally significant reduction in methane in cattle and other ruminant animals," he explained.
"With an estimated 10 million cows in the UK, each producing around 500 litres of methane a day, that would be a significant reduction."
He added: "Since antibiotics were banned, the hunt is on for new, safe, cheap ways to reduce methane production in ruminants."
Plants like coriander are an ideal solution, especially in parts of the world where expensive treatments are not an option.
The study appears in the Asian-Australasian Journal of Animal Sciences 2010.