by Gavin Stamp
BBC News business reporter
With 50,000 people estimated to earn some form of living from poultry farming in England it is clear bird flu poses a potentially significant economic threat.
Business are spread across England
Data about the industry is fragmented, something which has frustrated experts and policymakers as they prepare for a potential outbreak and gauge its likely effects.
All farmers with more than 50 birds must disclose stock levels for a national register by Wednesday, a move widely applauded by farmers.
Available statistics show the industry is a major one in European terms.
UK farmers produced 1.6 million tonnes of poultry meat in 2004, second only to France in the European Union.
Exports were worth £247m in 2004, according to the British Poultry Council.
In many regions
The industry is an important source of employment across much of England, while farms play a vital role in supporting suppliers and other businesses across rural communities.
Although there is no regional centre for poultry farming, there are major clusters in the south-west of England, East Anglia and in the border counties of Worcestershire and Herefordshire.
There are a smaller number of farms in Wales and Scotland.
"The industry is not really concentrated in any particular area," explains Peter Bradnock, chief executive of the British Poultry Council.
He says farms are often located close to slaughterhouses which, in turn, tend to be on the periphery of urban areas for easy access to markets.
"For biosecurity reasons, you don't want a lot of farms cheek by jowl," he says. "It would represent a risk for a variety of reasons."
According to figures from the Department of Food and Rural Affairs (DEFRA), there are about 10,000 farms in the UK breeding poultry for commercial purposes.
About 1,500 farms specialise in breeding broilers, while 27,650 farms have egg-laying hens.
Great and small
The industry is a rather lopsided one. While the majority of farms are small to medium-sized businesses, the larger concerns are responsible for the overwhelming bulk of poultry production.
For instance, 85% of UK breeding farms own fewer than 25 animals, but 200 farms account for about 95% of total production.
Bernard Matthews, the country's best known poultry business, has an annual turnover of more than £400m and more than 4,000 UK staff.
There are concerns that small-scale operators could be wiped out in the event of a bird flu outbreak in domestic fowl.
Experts says hygiene standards across the industry are high
"It could seriously destroy your business and I don't know how many people would survive it," one Salisbury egg farmer - a strong advocate of vaccinating animals - told the BBC.
"There is a problem about awareness of the size of the industry and how many people are employed. If you end up knocking the industry about, you have lost quite a big asset."
On the other hand, some farmers believe the make-up of the industry - with production concentrated in the hands of a relatively small number of large farms - would limit the economic damage.
"The way the industry is structured means that it is less likely to have a starburst effect like foot-and-mouth," says Mr Bradnock.
He points to the stringent biosecurity measures which poultry farmers have had in place for years to deal with infections such as salmonella.
What's more, he says, poultry farms are totally different businesses from beef farms, with far less movement of animals in and out of premises and more uniformity in terms of age and disease profile.
"Each farm is really a biosecure unit which exists in its own right," he says. "Part of the chain could be shut down very quickly without it having much of an effect on the rest of the sector.
"I don't believe this particular situation cannot be dealt with as effectively as the previous experiences of the past 25 years. We are prepared for it and we are on the lookout."
Most farmers are refusing to push the panic button, pointing out that 95% of poultry is "indoor-reared", reducing its likely exposure to the virus while free-range birds can be brought inside very quickly.
However, there is obvious concern about the costs of containing a potential outbreak, the level of compensation available in the event of widespread culling and the cost of cleaning and disinfecting farms.
British consumers are standing by poultry but for how much longer?
Inevitably, the issue of vaccination has aroused the strongest feelings.
The government says vaccination cannot provide a comprehensive solution because it would not prevent birds from getting infected.
One farmer says that although vaccination would be expensive for many farmers, it could keep them in business.
"Desperate days call for desperate measures," he says. "Most people, given the option between the loss that might occur if they get the disease or the chance of an expensive vaccine, are going to go for the latter.
"It might ruin your profitability for 12 months, but that would be nothing compared to the damage that it could do."
Tom Vesey, a Gwent farmer and chairman of the British Free Range Eggs Producers Association, says he is "open-minded" about vaccination.
"Obviously it is a concern, but we have to be positive," he says.
"Obviously if my flock got the disease, it would be catastrophic, but it can be contained and destroyed and we hope we can do it here."
The biggest long-term economic threat to the industry may turn out to be consumer nervousness about eating chicken and other poultry.
There has been no sign of a shopper backlash so far, unlike some other EU countries, and farmers are encouraged by that.
"The industry has invested a lot in its own biosecurity and retailers have spread the message that poultry is safe," says Peter Bradnock.
"Retailers have very strong brands and people trust them."