Much factory farming, says the RSPCA's farm livestock officer, Dr Martin Potter, amounts to institutionalized cruelty. His files contain information about animal living conditions that, as a zoologist specializing in animal behaviour, he finds disturbing and unjustifiable.
Among the examples:
More than 30 million laying hens, he says, are confined to battery cages in which four or more birds may share a space of only 18in by 20in.
The inability of hens to move properly in batteries means their bones often deteriorate until they are dangerously brittle. This condition, osteopenia, causes a high incidence of broken bones among hens being transported for slaughter. One leading study suggests that about 30 per cent of them have broken bones by the time they are slaughtered.
The breeding sow, which is intelligent, gregarious and a natural roamer, is often confined to a stall not much wider than an office desk, Potter says. It may be tethered during the whole of its four-month pregnancy. It will be able to stand up or lie down but not turn around.
Potter prefers to use the term "animal production systems" for what the man in the street calls factory farming.
He thinks it an entirely apposite phrase: "In Britain today many farm animals are treated as production units in factories. Considerations such as profit, production levels and cost-benefit analysis are applied to meat and animal product production just as they would be if the farmers were producing light bulbs or nuts and bolts. There is a paradox here. Most farmers are actually caring people but economic considerations have forced them to adopt systems that are inherently cruel."
The present-day priorities of the food industry are captured in figures for government research spending: more than 90 per cent of animal research money is for production efficiency, less than 5 per cent for animal welfare.
So where does ultimate responsibility lie? Farmers and retailers both tend to pass the buck to the customer, and the customer's approach is ambivalent.
But perhaps the mood is now changing. RSPCA officials are encouraged by the explosive interest in green issues and are looking for ways to tie animal welfare into that. Later this year, for example, the RSPCA will launch a food labelling initiative that tries to tap green sympathies.
Potter says: "We'd like to see a label on meat and eggs that says the food has been produced to basic minimum welfare standards. We're looking for a commercially viable system of production based on humane lines. Once we've got the guidelines for that drawn up we hope we can take them to the supermarkets and ask them whether they can supply eggs based on these alternative systems."
If the egg campaign catches on, the system will be used for other foods. But it will have to be commercially practical. Cash, of course, is the key to one of the RSPCA's dilemmas over farm animals.
"Should we," Potter asks, "be aiming at a Utopian system for animals, or should we compromise and say, 'OK, for a small increase in production costs the vast majority of farm animals in Britain can enjoy a substantially better life'?"
Everyone, Potter says, will have a different answer. His own would be to go for the attainable goal: "It's not beyond the wit of man to design welfare-based systems for large-scale food production."
