Wuzhishan
The Wuzhishan breed is very quickly being forced out of existence. They are a local breed raised only in the province of Hainan, China, a geographically isolated tropical-mountainous region. Very few people in this region raise this breed for production purposes because of the fast introduction of exotic species, and because of this some special attention may be needed in order to preserve this rare species. There are very few Wuzhishan pigs remaining, with some counts putting the number at as few as 30 at the time of writing, with only 3 boars, all in ex situ conservation. This is due in great part to this, very local breed, not being used as a market supply animal, but only by local farmers for self-consumption. Slaughter time for boars is after first mating with litter mates and mother-sows as well. This breed has been inbred for a long time.
Wuzhishan pigs are mostly black, with a white abdomen and inner-leg area. These pigs have long legs, long snout, level back and loin, small head, and narrow chest. Sows grow to be about 50-70 cm long, 35-45 cm high, 65-80 cm around the chest, and 30-35 kg in weight. Sows are able to give birth 1 or 2 times a year, with first pregnancy occurring at the age of 3 to 4 months. Boars first become sexually active at 1 to 1.5 months. Their litter size is relatively small, but the pigs are a very tough breed.
Wuzhishan pigs have an extremely small size and a strong recovering ability after surgical embryo transfer operations. This makes for a very interesting laboratory animal and they are internationally investigated as an interesting germplasm.