Stink-busting boffins aim to de-pong the great British pig

SCIENTISTS HAVE turned their attention to a new and unsuspecting target. They want to rid the countryside of ... countryside smells.

SCIENTISTS HAVE turned their attention to a new and unsuspecting target. They want to rid the countryside of ... countryside smells.

Top of their stink-busting list is the pig, which has long wallowed in its reputation as the king of foul odours, but they hope the breakthrough will eventually banish many other nasty rural scents.

By putting the pigs on a special diet, the researchers have dramatically reduced the compounds in the animals' waste responsible for its distinctive rotten-eggs smell.

According to Phil Hobbs, of the Institute of Grassland and Environmental Research in Devon, breaking down the proteins in feed before pigs eat it helps their digestion and reduces the amount and smell of their waste. "These proteins contain sulphur and nitrogen and, because they are only broken down at a late stage in the pig gut, they have the same impact on pigs as beans have on humans," he said.

Pig manure is also being treated by introducing additives to suppress odours and retain soil-enriching ammonia. But the MAFF-funded discovery is not just cosmetic. It reduces feed costs and cuts waste, and, according to Dr Hobbs, it also helps protect the immune systems of farmers and livestock by cutting the noxious sulphides and ammonia they inhale.

It is also a potential pollution-buster. It is estimated that up to 40 per cent of ammonia - a gas which produces algae blooms in rivers and acidifies sensitive ecosystems - and 35 per cent of the greenhouse gas nitrous oxide produced in Europe, comes from manure. Reducing ammonia emissions, say the scientists, could significantly cut the pollution of watercourses.

But the research was far from fragrant. In order to identify the offending chemicals in pig waste, the scientists first had to mimic the smell by concocting a synthetic brew.

When a batch was accidentally spilled by researchers in Manchester, it caused such a stink that three floors of a laboratory had to be evacuated.