Cows are pretty much destroying our planet with their burps. And lordy lord, do they burp a lot.

Your average belching bovine is pumping out as much as 340 grams of methane a day.

That’s according to Charles Sturt University honours student Lucy Watt, who is on a mission to learn everything there is to know about the cow burp.

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Ms Watt spent two months as a dairy research intern at Michigan State University in the US getting to the bottom – or, the front – of this very important and very smelly problem.

A high ruminator – in common parlance a ‘smelly old cow’ – burps out an average of 340 millilitres of methane a day, Ms Watt found, while a more polite farmyard lady restricts herself to an average of 270ml, covers her mouth with her hoof and says ‘excuse me’ afterwards.

Methane is one of the gases attacking our ozone layer and turning up the temperature on our delicate planet, according to climate change scientists.

Getting cow methane under control is a “major research focus”, Ms Watt told The New Daily, because 98 per cent of Australian dairy farms let their lovely ladies graze on grass, which pack a seriously gassy punch.

Armed with a microphone-equipped cow collar and a doo-hickey to measure methaneyness (known scientifically as a “gas quantification system”), Ms Watt listened to and smelt, from a scientifically safe distance of course, a whole heap of cow burps so you don’t have to. You’re welcome, Earth.

“When they’re being milked, and their head is in the feeder, there’s actually a gas quantification system that measures the concentration of methane that’s emitted as they, like, as they belch,” Ms Watt said.

“Understanding this could help farmers optimise feed management strategies to reduce the cost of production, improve milk production and maximise on-farm efficiency,” she said.

Ms Watt’s research could turn out to be helpful for “methane mitigation strategies”. So, apart from strapping filtration devices to both ends of our favourite steak-and-milk producers, we might instead be able to feed them burp-free grass, or breed less burpy cows.

As celebrity scientist Dr Karl wrote for ABC Science, most of us – in fact, “practically all of us”, blame cow methane on what comes “from the back end”, when in fact what comes from the front is far worse.

In fact, only 13 per cent of a cow’s methane comes out of her rump, compared to 87 per cent in the form of ‘eructation’ – the scientific term for a whopper of a gut bubble that took the up elevator.

That makes cow burps almost seven times worse than cow farts.

Worst still, methane is 22-or-so times more noxious a greenhouse gas than Co2 (carbon dioxide), Dr Karl said, despite the latter seeming to cop most of the bad press.

According to Dr Karl, livestock – cows and sheep – produce about 20 per cent of the world’s methane output.

Cows produce a lot of this harmful gas because the bacteria in their guts, which break down the feed they digest, are what Dr Karl calls “messy eaters”.

They are a bit inefficient at what they do. Instead of turning all the cow’s food into energy, they waste about six to 10 per cent it, which gets burped and farted out as methane.

Pleasant.