New diet for pigs 'will beat the pong'

Pigs may be about to shed their age-old image as the world's number one stinker. Scientists believe they can take the sting out of the pong produced by porkers with a special dietary supplement.

Pigs may be about to shed their age-old image as the world's number one stinker. Scientists believe they can take the sting out of the pong produced by porkers with a special dietary supplement.

By adding an unlikely combination of yucca extract, amino acids and soy bean to a low-protein diet, researchers have managed to halve the nitrogen and ammonia levels given off by pigs, resulting in a dramatic drop in manure smell.

The research, part of a £2m (£1.3m) odour solutions initiative at Purdue University in Indiana, is good news for the growing number of urban families who have found moving to the countryside to be a smelly experience.

Various surveys have shown that pigs and their manure are the main source of smell complaints from people living downwind of farms.

To tackle the pig odour problem, researchers, led by Professor Albert Heber, first had to develop a "swineometer" to rate the strength of the smells.

Eight volunteers were paid to sniff air samples taken from a manure reactor. The smell was then rated by the amount of fresh air that had to be added to make the smell tolerable.

Just how soon the ammonia-reducing diet will be on the British market is not clear. But its introduction may be speeded up by the fact that the diet not only reduces the smell, it is £1.50 a ton cheaper than run-of-the-mill pig food.