An unlikely destination for a weekend family outing would probably be a pig farm. But the Huateng pig farm in Tongxiang, Zhejiang province, is one of the most popular for local parents.

It has a playground, mini zoo, library, greenhouses, barbecue restaurant and no unpleasant smells, thanks to technologies adopted to make the farm smarter and greener.

"Many of the facilities are for parents and kids," said a representative of Zhejiang Huateng Animal Husbandry, which has been branching out into tourism.

Visitors to the farm come from across the Yangtze River Delta. The average number of visits per day is around 1,000, according to the company.

"When the weather is nice," said a local resident, "the parking lot outside is always packed with cars."

One of the technologies that have contributed to the pleasant environment is a pig waste treatment process.

After treatment, pig excrement becomes biochar organic fertilizer, which "contains nutrients and provides strong water retention," said the Huateng representative. Treated pig urine becomes liquid fertilizer and secondary wastewater is cleaned to raise fish and wash the pig houses.

The biochar organic fertilizer sells well, the representative said. "Some 20,000 metric tons of organic fertilizer is sold annually."

The farm uses pure plant extracts, in the form of a fine mist, to disinfect and deodorize its facilities every day. "This is why there are no foul odors around the farm," said the representative.

Huateng has built up its technology portfolio by strengthening research and bringing in talent.