(Yicai Global) Dec. 27 -- Shanghai shipped its first batch of 160 live pigs from a new breeding base to Hong Kong via rail yesterday.

The breeding center on Chongming Island raises hogs for about 100 days to a typical weight of 50 kilograms, before running them through quarantine and shipping them off to the special administrative region, state-backed online news outlet The Paper reported.

China's largest city exports about 20,000 live pigs to Hong Kong each year, making up 80 percent of the region's total supply. But it has brought in new measures to restrict farming in recent years as it looks to protect the environment and expand its urban area, forcing a number of hog breeders that used to supply Hong Kong to shut up shop.

However, one supplier set up a swine breeding site on an island north of the city to raise up to 2,400 hogs using advanced automated farming methods and equipment.