Back in 1950 chicken was such a treat that most British people ate less than a kilo of it in a year. Now we each eat on average 23kg of chicken a year. Sometimes it seems we eat nothing else: drumsticks, skinless economy breasts, pies, soups, tikka-flavoured sandwich fillers, Thai curry, barbecue buckets and, of course, nuggets.
To satisfy our insatiable demand, 860 million birds are reared in the UK each year. That's almost half the meat we eat. We buy 16 million fresh chickens a week, most of which are reared here, and eat yet more. These are mostly imported from Brazil and Thailand disguised with sauces and coatings, breadcrumbs and stuffings, in ready meals.
Chicken is no longer considered a luxury. To keep us supplied with bargain birds, more than 93 per cent of those produced in the UK are reared on factory farms. Here, up to 50,000 birds, and typically around 25,000, are packed into sheds, dimly lit to discourage movement and ensure they put on weight at an unnaturally fast rate.
Having reached the required size twice as quickly as factory farmed chickens did just 30 years ago, the average intensively reared bird is ready for slaughter at 5-6 weeks old. By then there could be up to 19 birds per square metre. Because they've grown so quickly, their bones can be weak, joints can become infected and some have difficulty walking. Ammonia from the build-up of faeces in the litter on which they sit can cause breast blisters and burns on their feet and legs. The tell-tale 'hock burn' and breast blisters are evidence of poor conditions.
Chicken has never been cheaper. According to Defra, while most food has increased its real price by 50-200 per cent in the past 20 years, chicken has increased by just 15 per cent, making it cheaper than ever in real terms.
Cheap chickens are ammunition in the supermarket price wars. Not long ago, the price of a whole chicken was as low as £2. These were British chickens with a Red Tractor symbol, produced to the Assured Chicken Production (ACP) basic (voluntary) welfare standards. The Red Tractor symbol offers a guarantee of the health of the flocks and food safety, and that chickens have been reared to a legal minimum standard.
But for producers rearing chickens as cheaply as possible, and as the cost of wheat, which accounts for 50 per cent of a broiler chicken's feed, goes up, margins are so low that it's difficult to invest in changes to their chicken rearing systems.
Other than the most basic measures to prevent cruelty to farm animals, there are no legal restrictions on how many birds may be packed into a given space - the stocking density - and welfare of chickens is only just about to be protected by law.
A recent EU directive has brought in new rules for chicken producers, and may include welfare labelling. However, the regulations, which will come into force in 2010, aren't as positive as they may at first appear. Theoretically, the new rules could allow even more birds to be kept in the same space than is the norm at present.
Currently, around 90 per cent of British chicken farms follow the ACP voluntary code. However, the RSCPA says that the ACP welfare standards are too low. Stocking densities, the Society claims, are unacceptably high and chickens are kept in conditions that encourage them to gain weight as quickly as possible. Only 4.5 per cent of chicken produced in the UK meets the RSPCA's Freedom Food label animal welfare requirements. According to Compassion in World Farming, Red Tractor standards meet only five out of its 13 animal welfare criteria.
The labels 'free-range' and 'organic' sound reassuring. Free-range chickens must have access to outdoors for at least half their life and are slower grown, for slaughter at eight weeks old (10-11 weeks if they are organic). This means they don't suffer the problems that afflict the fastest-grown chickens.
Organic chickens are allowed to grow more slowly, are not given routine antibiotics or unnecessary medication, and are fed an organic diet. All organic chickens are free-range, with more outside space than other free-range birds, and smaller flock sizes. Birds certified as organic by the Soil Association - 30 per cent of all organic chickens - will have been reared to the highest welfare standards.
However, free-range (and even some organic) is not always a guarantee of good welfare standards. This is because the stocking densities can be as high for free-range birds as for indoor-reared birds. They may not be able to get outside easily and space itself may be unsuitably exposed, for example. Though the indoor environment is equally important, no extra rules apply to that.
Freedom Food chickens are not necessarily free-range, and some chickens reared to higher welfare standards indoors enjoy better lives than some of their free-range counterparts. While most indoor broiler chickens are slaughtered at 35 days, Freedom Food birds will not reach the 2.2kg weight preferred for slaughter until 49 days - seven weeks. The best sheds have windows to give the chickens daylight, provide enough space for the birds to move freely and flap their wings, perching opportunities and a semi-organic diet.
If you're concerned about welfare standards, look out, too, for supermarket chickens that are labelled as 'slower-grown', some of which, though not free-range, may also be better for the animals' welfare - and are a significant improvement on the fastest-grown, most intensively reared birds.
Thanks to EU regulations we can at least choose whether to buy eggs from hens kept in cages, indoor barns where they can move freely, or from free-range birds, with daytime access to outdoor runs whenever they want. This information must be given on egg boxes. Eighty-five per cent of UK eggs come stamped with the red 'Lion Quality' mark. The mark indicates that they're included in what is essentially a food-safety scheme (all Lion Quality eggs are from hens vaccinated against salmonella) but the scheme also sets higher standards of welfare than that required by law.
While the UK has the largest number of free-range hens in Europe, and demand for free-range eggs currently exceeds production, 56 per cent of eggs sold still come from caged hens; six per cent are from barn hens.
The RSPCA will not give the Freedom Food label to eggs from caged hens, of which there are an estimated 19 million. Their laying lives are short - most are no use after a year - and miserable.
Free-range laying hens usually have their beaks trimmed to prevent them pecking each other, and most of the birds are kept in very large flocks. Freedom Food laying hens have larger range areas. Organic laying hens are kept in smaller flocks than free-range, have twice as much indoor space - and Soil Association hens have more outdoor space. Their beaks are not trimmed, either.
The 'Red Tractor' symbol is part of a voluntary scheme. Birds with the symbol meet assurance standards, guaranteeing the health of the flocks and food safety, and that chickens have been reared to a minimum welfare standard.
'Extensive indoor' or 'barn-reared': these chickens mustn't be packed more than 15 to a square metre of living space (and not more than 25kg/sq m in combined weight); they shouldn't be slaughtered before they are 56 days old.
'Free-range': the maximum indoor stocking density is 13 birds per square metre (and not more than 27.5kg/sq m); in addition, each bird, for at least half its life, should have continuous daytime access to open-air runs with a maximum density of one bird per square metre.
'Traditional free-range': the maximum indoor stocking density is 12 birds per square metre (and not more than 25kg/sq m); continuous daytime access to open-air runs should be given from the age of six weeks, and these runs should allow at least 2sq m per chicken; poultry houses shouldn't contain more than 4,800 chickens. Slow-growing varieties of chicken should be used, with a minimum slaughter age of 81 days.
'Free-range - Total Freedom': in addition to the criteria for 'traditional free-range' chickens, these birds should have open-air runs of unlimited area.
Organic chickens are free-range and slower grown, slaughtered at 81 days, given organic feed and no routine antibiotics. They are kept in smaller flocks, with more space to move about inside and out.
Freedom Food is the scheme for animals reared to the RSPCA's welfare standards. Chickens are slower grown and stocking densities are lower, though they are not necessarily free-range birds.
'Farm fresh' is a meaningless description. The eggs could have been laid by chickens farmed in battery cages.
'Free-range' egg production provides chickens with daytime access to runs covered with vegetation, with a maximum 2,500 birds per hectare.
Organic eggs are from chickens with more privileges than free-range and are produced according to EU laws on organic production. Growth promoters, artificial pesticides, fungicides, herbicides and commercial fertilisers cannot be used in the feed for organic production.
The 'Lion Quality' mark on the shell of eggs is a guarantee that the eggs were produced to higher standards than required by UK or EU law. All Lion Quality-marked eggs have complete traceability, a 'Best Before' date on the shell and compulsory vaccination of the laying flock against salmonella.
Freedom Food eggs meet the RSPCA's animal welfare standards. Battery hens do not meet the standard, only barn or free-range eggs qualify for this label