As cow 777 passes from the herd, nudged by an automated gate into the milking parlour at Kemble Farms, the signal from the transponder in the bracelet on her foreleg is read by the Cotswold estate's computer. The cow is identified and logged in while she files down the stalls. When 777 enters the empty berth at the end of the line the bar opens for the cow behind, so the stalls fill up without the need for human intervention. In the pit below, three eastern European workers move quietly up the lines attaching automatic milking teats to 36 sets of udders at a time.
As the vacuum begins to suck, 777's milk flows down the pipes and through an underground meter which measures and records her output, while information from the pedometer also attached to her foreleg is analysed by the latest software to calculate how far she has moved inside the adjoining cowshed since her last milking. When 777 comes into season she will walk more than usual and the computer will mark her down for her next insemination. If she has not walked as much as usual she may have an udder infection or the lameness to which cows bred for intensive dairy production are prone, and the computer will filter her out for treatment.
As 777's udders empty and the milk stops pumping, sensors in the machine detect the interruption to the flow and water is forced automatically back up the pipes to clean cow and equipment. Then the teats pop off by themselves, leaving 777 to exit back to the shed.
Kemble Farms is one of the most efficient dairy operations in the country. The cows give so much milk they are emptied three times a day. Yields are typically 9,000 litres per cow per year, not the highest known since some farms have now broken the 10,000-litre barrier, but a long way above average and spectacular compared with a decade ago, when average yields were nearer 5,000 litres per cow. Thirty years earlier, average yields were 3,500 litres.
The herd size here, usually around 700 cows, puts Kemble in the super-efficient league too. The average number of cows in a dairy herd in the UK is now 100; in 1994 it was 79. A £2m investment in a light and airy, aircraft-hangar-sized shed, where the cows can be kept indoors seven months of the year and fed the concentrated feed they need to maintain such levels of production, has enabled the family business that owns the farm to achieve economies of scale and cut labour costs. And yet Kemble Farms has been selling milk at less than the cost of production. Its costs - fuel, fertiliser, water and feed - have gone up 8% in the last 12 months, but the price it is paid for its milk by Dairy Crest, which processes and packs it for Sainsbury's, has fallen by 8% over the same period. Like most of the British dairy industry it is struggling to make money.
Today the National Federation of Women's Institutes is launching a Great Milk Debate with a conference in London and meetings around the country to address the crisis in dairy farming. The WI's 211,000 members voted the plight of milk producers their top priority last year, and want farmers to get a fairer share of the money spent on milk in the shops.
The price of milk in the shops has risen roughly 20% in five years, from just over 44p a litre in 2002 to just over 53p in 2007. Yet the price paid to farmers has fallen.
In 1995, producers got 24.5p a litre for their milk; the average today is 18p a litre, which represents a loss of more than 3p on every litre. Kemble Farms has been getting 19p a litre. The result has been a huge rise in supermarket profits from milk, but an exodus from dairy farming, which is still accelerating. On average three dairy farmers leave the industry every day; there were 35,000 dairy farms in the UK in 1995 and there are now only about 19,000. A further 3,000 dairy farmers told the Milk Development Council in a survey earlier this month that they plan to leave in the next two years.
Tesco, which sells about a quarter of the country's fresh milk, promised at the beginning of this month to pay more to farmers. Its move follows schemes by other retailers to support farmers. Kemble Farms heard last week that it will get a rise of roughly 1p a litre, but that will move it only from loss to break-even. Few believe the dairy industry's problems are solved.
"We either pack up or intensify further," says David Ball, one of the directors of Kemble Farms. "We've already increased output 15% in the last year. We could keep more cows, and get a further 25%. We're aiming for 10,000 litres a year per cow in the next few months. We would be driving every-thing, the animals, the plant, to the maximum. In a factory we are used to that idea of 24/7, but with animals and land there are other considerations. We resist treating animals like machines."
Kemble Farms has high standards of animal welfare - it is audited by RSPCA Freedom Foods. But as Mr Ball explains: "From the consumer point of view, dairy equals cows in nice pasture - and we're being driven away from that, until we follow the poultry world."
The irony for Colin Rank, one of the family that owns Kemble Farms, is that his cows drink water from a Cotswold spring that he could bottle and sell for 80p a litre. "We're giving it to cows and devaluing it by turning it into milk. Like all dairy farmers we could pack up tomorrow and do something better with our capital, but we do it because we have an emotional investment in the land and the animals. And we know there's a market for our product, if only the market worked."
