Viral video clips on social media show cows literally jumping for joy as they are released to pasture after a winter cooped up indoors.

But many cows these days don't get to experience green meadows and blue skies - ever - as more and more large-scale European farmers chase bigger profits by investing in intensive, indoor milk production.

The move toward a system of so-called mega-farms, housing up to 2,000 cows in factory-like conditions, can be traced back to developments in dairy cow farming in the United States.

But in Europe, this has been exacerbated by the sector's worst crisis in modern times, due in part to the European Union's abolition of national milk quotas.

Three years ago, the market price for moo-juice plummeted by almost half amid massive overproduction - caused by a drop in demand from China and Russia. The crisis forced thousands of European dairy farmers out of business.

Traditional milk production threatened

In the United Kingdom, amid fierce competition, the number of dairy farms has dropped by two-thirds over the past decade, to around 9,500.

Those that have survived are being increasingly driven by the need for greater efficiency and demands from larger supermarket chains for the lowest possible price.

This, environmental and animal welfare groups contend, contributes to pollution and ecological footprint, as well as harming cows. Some farmers say it's also decreasing the quality of the milk.

Britain's National Farmers Union (NFU) played down the impact of larger, indoor dairies, telling DW that the average UK dairy farm still houses just 148 cows.

"Yes, we have larger farms of up to a thousand cows, and some of these may be housed all year-round - but that doesn't mean that the standards of health, welfare and milk quality are compromised," said Sian Davies, the NFU's Chief Dairy Adviser.

While the UK is a long way from reaching the scale of some US mega-dairies - where up to 40,000 cows are housed - farmers continue to face severe pricing pressure, which some analysts think will push more of them towards creating larger dairies.

World Animal Protection thinks traditional milk production methods in Britain are dying out much quicker that previously thought, citing figures from the Department of the Environment, Food and Rural Affairs (DEFRA).

"Research conducted by DEFRA said that only 30 percent of the farms thought they were traditional pasture-based dairy farms," said Ian Woodhurst, UK farming campaign manager at the London-based World Animal Protection.

"It's very unclear what the picture is: How many days the cows are actually out, and how many intensive indoor dairy farms there are," he told DW.

Environmental and animal welfare concerns

But while some farmers insist that intensive, indoor milk production is their only chance for the future, animal rights groups warn that cows are being pushed to their physical limits to produce the most milk possible.

"There is an increase in lameness because they're on concrete and increased rates of udder infections," Woodhurst pointed out.

Overcrowded indoor farms can drive some animals to aggression that affects the rest of the herd, Woodhurst added. Their usual social structure is often altered within confined spaces.

Campaigners also warn over the environmental impact of more intensive dairies. As well as the risk of water and soil pollution, large-scale farms require huge amounts of animal feed.

Factory-farmed cows eat grain, not grass - and that has to be produced.

Arable crops produced for animals require substantial space, Woodhurst pointed out, citing deforestation and the use of pesticides, herbicides and fertilizers, all of which contribute to greenhouse gas emissions.

'Pasture promise' to help small-scale farmers survive

Longtime farmer Neil Darwent said that 2015 and 2016 were among the most difficult years in living memory.

"We saw prices in drop from something in excess of 30 pence a liter [0.33 euros per liter, or $1.44 per gallon], to 18 pence a liter," he told DW.

While many colleagues move their herds indoors permanently, Darwent has bet his future on maintaining outside pasture time for his cows.

Having been outspoken against the trend toward mega farms, he created the free-range "pasture promise" label three years ago so consumers can be assured that the milk they are drinking comes from cows that have spent the maximum possible time outside grazing - in the case of the UK, at least 180 days a year.

Although milk prices have recovered somewhat, the Somerset-based farmer believes this small premium of 2 or 3 pence per liter for free-range milk will help small-scale players survive.

Some of Britain's largest supermarkets are already on board - including Asda, which is owned by the US retail giant Walmart - helping free-range milk to gain traction.

Darwent said the farmers who have signed up to the free range dairy label are audited to prove they are keeping to the 180 day pasture promise - and many keep their cows outside for longer, although Britain's climate often doesn't allow for a full year of grazing.

The NFU's Davies insisted that the vast majority of cows in the UK still graze outside.

"We need consumers to understand why cows are housed for the winter period, and that when they are housed, the conditions are extremely good. It's not in the farmers' interest to compromise on cow comfort." she said.

Darwent agreed. In wet and cold Britain, "At certain times of the year, it is definitely better for cows to be indoors rather than out."