Dairy is done differently in the United States. LAUREL STOWELL tours a farm in Oregon.
Imagine a dairy farm with no fences, because the cows are all kept in sheds.
They're milked every eight hours around the clock. On average they last three to four milking seasons in this regime, before becoming "hamburger".
Rickreall Dairy, in the fertile Willamette Valley in Oregon in the United States, is a CAFO - a Concentrated Animal Feeding Operation. It's a small one as they go - a dairy farm across the Willamette River has 10,000 cows and another US farm has 30,000.
Factory farming, with animals fed indoors, is the usual way dairy operates in the United States. It's just starting in New Zealand.
It has advantages, in that manure - the biggest environmental concern - can be handled more easily. But many Kiwis struggle with the idea of cows standing in sheds, on concrete, rather than out eating grass under the sky.
The Rickreall mega-farm has many economies of scale and enables high production.
"We get in one year what my dad got in 10," herd manager John Haarsma says.
He's worked there 22 years, and was brought up on a dairy farm.
Despite cows producing a lot of milk each day, a milk price of US$16 per 44 litres just allows the operation to break even.
Milk prices are global. The past seven years have been as tough for US dairy farmers as their New Zealand counterparts - especially those with high debt.
"Our producers lose money every month. How they manage to [stay in business] is a mystery of life," said Tammy Dennee, the legislative director of the Oregon Dairy Farmers Association.
Oregon used to have 1200 dairy farms. Now there are only 200, with most smaller than Rickreall Dairy.
Things were especially tough for the farmers in 2009, when the milk price dropped suddenly from a high.
'"It was so bad, we just about gave up," John said.
The farm was going to its bank to borrow more money every two weeks. Workers feared losing their jobs and had a meeting with owner Louie Kazemier. They liked their jobs and told him "We are in if you are in".
They farm survived and the milk price rose. In an "awesome" 18 months Rickreall Dairy paid off a lot of debt. But at US$16 things aren't so great now.
The operation gets by through a complex network of trade interactions with its neighbours. It sells manure as fertiliser, and dried and sterilised manure solids for use in potting mix.
"Sometimes the manure is better money than the milk," John said.
The farm gets free waste from neighbouring grass seed growers to use for cow bedding. It takes on wastewater from a neighbouring fruit dehydrating business to use for irrigation.
So, what is life like for the cows?
Calves are born in a maternity shed, where 160 may be due over a fortnight. They stay with their mothers for a few hours, before being moved to a calf barn.
In individual stalls they get first colostrum, then two bottles of milk and some solid feed and water every day.
Bull calves are sold every fortnight - taken to California to be fattened for beef.
When they reach heifer age the female calves are moved to another barn, where they have solid food. When they reach breeding age they are artificially inseminated, give birth, are moved to the cow barns and milked every eight hours.
They drink a huge amount of clean water every day, and eat a mix of solid food that costs about US$6 a day per cow. If they get mastitis they are sent away for slaughter.
But John says not many do. The average per farm is 1 per cent of cows, which for Rickreall milking 1600 a day would be 16 cows. John only had four in the sick bay.
Rickreall Dairy is 445ha of flat land with 3500 cattle in barns, and it grows maize to feed them on 330ha.
John is milking 1600 cows, raising 1700 to replace them and hosting 200 cows that are dry. All are Holstein.
The farm holds milk in two 57,000 litre tanks, emptied twice a day. It's quickly cooled from 36C to 1C.
Each cow has a computer chip, and John can look at an app on his phone to find out how much milk they give. Their udders get a splash of biodegradable iodine before and after milking.
Milking takes just four or five minutes, in a shed that accommodates 46 cows at a time and is sluiced out twice a day.
For best production, the cows need rest and comfortable beds. They suffer in hot weather, and in summer it can get up to 37C in the Willamette Valley. John has fans switched on when the temperature tops 15C, and sometimes gives them showers as well.
Far from pining for green pastures, he says the cows choose to be indoors most of the time.
All those cows make a huge amount of urine and manure. It falls on hard surfaces and is washed into a sump. The solids are screened out and the remaining liquid is added to two 6ha irrigation ponds.
Solids are quickly composted in huge drums. Air is pumped in and the manure solids heat up to 70C - enough to kill any bacteria. The semi-dry solids are used as cow bedding, with 60 per cent sold to nurseries for use in potting mix.
Nutrient-rich fluid from the ponds is used to irrigate Rickreall's own crops - mainly the 800ha of corn grown to become silage. Any extra solids are sold to neighbours.
The farm is expected to apply only enough nutrient to feed the crop, rather than allowing nitrogen to filter out into groundwater or waterways.
But owner and crop manager Louie Kazemier said nitrogen moves everywhere in US systems, just as it does in New Zealand.
"Up, down and sideways."
He didn't know the exact amount leached from his farm, but said Horizons Regional Council's One Plan goal of a maximum of 25kg of nitrogen leached per hectare seemed reasonable but ambitious.
His indoor system avoids nitrogen leaching through the ground from urine spots - one of the main leaching sources where cows graze pasture.
The cows' diet is decided by a nutritionist who comes twice a month. Ingredients are stored in sheds and moved around by the tonne before being mixed.
There's corn, grass and clover silage, hay, cottonseed, sugar beet pulp, canola and even some bakery waste. The cows eat many kilos a day.
The dairy enterprise has 25 staff. Apart from John and Louie they are all Hispanic, mainly Mexican. President Donald Trump's efforts to send Mexicans back to their country will hurt the dairy industry, John said.
"We need them. We have created a generation of youngsters from the US with more interest in screen time than work."
Rickreall's three-person milking teams work day and night, in eight-hour shifts. Two are milking the cows and the other is having a break or bringing in another lot of cows. Some milk right through the hours of darkness. It's not most people's ideal job, but the farm has a very low staff turnover.
"We try to make it as comfortable as we can."
For its low staff turnover, water reuse and other innovations, Rickreall Dairy received the United States' Outstanding Dairy Farm Sustainability Award this year.
Louie has been proactive about dairy publicity, running many tours on the farm. He wants to show dairy doesn't have to look or smell bad.
Though the hundreds of cows are treated well, they are not pets.
"They're not pets. They're our way of life," said Louie's daughter Stacy Foster, who was brought up on the farm.