CHINA (REUTERS) - On Yaji Mountain in southern China, they are checking in the pigs a thousand head per floor in high-rise 'hog hotels'.

At these seven-storey so-called 'hog hotels' in China, it is check in time.

But for the guests inside, it is no holiday.

This is high-rise pig farming at its most intense.

High-rise buildings with lifts and 1,000 pigs per floor.

It is an answer to the demand in China for pork as it goes up, and up.

Beijing is also pushing ahead to modernise the country's farming section and create wealth in rural areas.

Similar hog farms have been tried in Europe of two or three floors, but many have been abandoned - largely because of public resistance there to large, intensive farming.

This one in China's Yaji Mountain plans to expand - upwards.

When it does it will have 13 floors and will be the tallest building of its kind.

This will house 30,000 sows by the end of the year, producing more than 800,000 piglets annually - which would make it the biggest, most intensive breeding farm in the world.

Success here could have implications across densely populated, land scarce Asia.

Similar farms are already springing up across China and South Korea.