The Soil Association can reveal that a recent government survey shows that organic laying hen farms have a significantly lower level of Salmonella. Salmonella is a bacterium that causes one of the commonest forms of food poisoning worldwide.

The study showed that 23.4 per cent of farms with caged hens tested positive for salmonella compared to 4.4 per cent in organic flocks and 6.5 per cent in free-range flocks.

The research also showed that the highest prevalence of salmonella occurred in the largest holding size category (30,000 birds or more). This was over four times the average level of salmonella found in flocks closer to the maximum size allowed under Soil Association organic standards.

Intensively farmed chickens reared for meat can be housed in flocks 30 – 40,000 strong. Even the RSPCA’s Freedom Food standards allow 16,000 egg-laying birds per house, and there is no limit on flock size for free-range meat birds.

In contrast, Soil Association organic standards recommend flock sizes of 500 – with absolute maximum flock sizes of 1,000 for meat birds and 2,000 for egg birds allowed only with special permission and additional management measures in place.

These results support Hugh Fearnley-Whittingstall and his ‘Chicken Out’ campaign to improve the welfare standards of chicken production. It also adds weight to the argument that although ‘free-range’ production would certainly be a positive step forward, it is still some way behind the Soil Association’s organic poultry systems , which ensure truly free range birds and offer the highest standards of animal welfare as acknowledged by respected animal welfare groups such as Compassion in World Farming.

Some battery egg operations have as many as half a million birds. Most battery cages house four or five birds, each with about as much room as an A4 sheet of paper. All animals on Soil Association organic farms must have access to outdoor ranges and pasture, with an emphasis on enabling the animals to express their natural behaviour. Unlike intensively reared birds, organic chickens can’t be given routine doses of antibiotics which weaken the animal’s natural immune system so increasing reliance on drugs, as well as being linked to creating antibiotic resistant ‘superbugs’ with serious human health implications.

There are now approximately 29 million egg-layers in the UK over 70 per cent of which are housed in battery cages. Today three-quarters of the UK’s eggs come from fewer than 300 units, each with 20,000 or more layers.

Emma Hockridge, Soil Association policy department said: “Anyone watching Hugh and Jamie reveal the appalling conditions millions of chickens endure in the cramped, windowless sheds of factory farms will be in no doubt that organic and free-range chickens have a better life.

“This research confirms the Soil Association’s view that there are serious potential human health implications from such intensive systems. Whilst Salmonella food poisoning can be avoided through proper cooking of eggs and meat, anything that reduces the incidence of this bug should be encouraged – like genuine free-range, organic farming.”