Jiaxing Black Pig

Jiaxing Black Pig

　　The Jiaxing Black Pig is a well-known and superior local breed in China, part of the main group of Taihu Pigs. It is famed for its high fertility, early sexual maturity, ability to thrive on rough feed, strong adaptability, good meat quality, and significant hybrid performance. Its core production areas are situated across counties (cities, districts) in Jiaxing City, Zhejiang Province, and it has been distributed across the whole province, as well as in neighboring provinces (cities) such as Shanghai, Fujian, and Anhui. It is a key protected breed in Zhejiang Province. In the late 1970s, China gifted five Jiaxing Black Pigs to France. French breeding experts cherished them immensely and leveraged their exceptional reproductive capacity. After more than two decades of selective breeding, these pigs played a significant role in improving the quality of French pig breeds.

　　　The Jiaxing Black Pig adapts well to local feeding and environmental conditions. In the region, summer temperatures can reach up to 40°C and winter lows can drop to -12°C. Most rural pig farming is carried out in confined housing, where sows rarely see sunlight year-round. Their diet is low in protein and high in crude fiber. Despite these conditions, sows maintain relatively high reproductive performance. Health surveys and serological monitoring of farms, large-scale pig breeders, and smallholders raising this breed have shown that while pigs in higher-density, lower-nutrition settings are susceptible to respiratory diseases, there have been no cases of Class I infectious diseases.

　　2. Breed Origin and Development

　　2.1. Origin

　　　　The Jiaxing Black Pig is a local variety of the Taihu Pig group. The region has a pig farming history of about 7,000 years, with records from the Ming Dynasty mentioning sows giving birth to 14 piglets in one litter. Over centuries of domestication, local farmers have accumulated rich experience in selection and breeding. Coupled with the region’s location in the Taihu Basin — characterized by a warm, moist climate and abundant feed resources — these factors have gradually shaped the Jiaxing Black Pig into an outstanding local breed, primarily valued for its high litter size.

　　2.2. Population Size

　　　　2.2.1. Sow Count: By the end of 2006, there were approximately 74,800 Jiaxing Black sows in the city, including around 140 breeding sows in the core group at Shuangqiao Farm.   2.2.2. Boar Natural Mating Capacity: Each boar can naturally mate with 500–600 sows per year.   2.2.3. Boar Artificial Insemination: Due to limitations in the number of available sows, only a very small proportion of boars are used for artificial insemination. The male-to-female ratio for artificial insemination can reach 1:2,500 to 1:4,000 sows per boar annually.   2.2.4. Initial Breeding Age and Service Life: Boars should not be bred until at least 6 months of age, and can be used for 4–5 years, though typically around 3 years. Sows should not be bred until at least 5 months of age, can be used for 6–7 years, though usually around 4–5 years.

　　2.3. Breeding Pig Sales

　　　　Jiaxing Shuangqiao Farm (original breed farm) provides 500 Jiaxing Black breeding pigs and around 1,500 Jiaxing Black crossbred (two-way) sow pigs annually. Jiashan County’s Mulberry Seedling Breeding Farm (a provincial first-class breeding pig farm) can supply around 300 breeding pigs per year. The city produces 1.5 million Jiaxing Black two-way crossbred commercial pigs and approximately 2.6736 million three-way crossbred (two foreign and one local breed) commercial pigs annually.

　　3. Body Shape and Appearance

　　3.1. Hair Color, Mane, and Skin Color

　　　　The coat is entirely black, sparse, short, and soft. Adult breeding pigs have long and stiff manes on the withers. Skin tones vary between purplish-red, light gray, and black, and the skin is relatively thick.

　　3.2. Body Shape and Features

　　　　3.2.1. Body Type: The Jiaxing Black Pig has a medium-sized, sturdy build with a well-proportioned structure.   3.2.2. Head: It has a broad forehead and wide head, a long and slightly concave snout, and distinct wrinkles on the forehead, categorized into three types: Shouzi (longevity character), Mianzi (horse face), and Wengzi (old man character). The ears are large, soft, and drooping.   3.2.3. Trunk: It has a relatively long back and loin, a slightly drooping but firm belly, and a sloping rump. There are numerous teats, generally 8–10 pairs, classified into two types: “Suoyi Nai” (straw raincoat teats) and “Dingxiang Nai” (clove teats).   3.2.4. Limbs: The limbs are slightly elevated, with the hind legs being lean and wrinkled, and some exhibit a lying stance with splayed toes.   3.2.5. Bone and Muscle Development: Bones are thick and sturdy, though the rump muscles are not particularly well-developed.

　　4. Body Measurements and Weight

　　　　4.1. Adult Boars (21 individuals): Height 77.08 cm, body length 139.80 cm, chest girth 118.10 cm, weight 128.28 kg.   4.2. Adult Sows (50 individuals): Height 69.41 cm, body length 124.30 cm, chest girth 111.16 cm, weight 102.90 kg.

　　5. Production Performance

　　5.1. Fattening Performance

　　　　When fattened from 25–75 kg under a diet with 11.75 MJ/kg digestible energy and 13.5% crude protein, the Jiaxing Black Pig gains an average of 425 g per day, consuming 3.96 kg of feed per kilogram of weight gained.

　　5.2. Slaughter Performance

　　　　At a slaughter weight of 75 kg, the Jiaxing Black Pig has a carcass length of 86.3 cm (straight), 72.0 cm (diagonal), backfat thickness of 3.8 cm, dressing percentage of 67.9%, skin thickness of 0.5 cm, loin eye area of 16.3 cm², fat content of 30.8%, skin proportion of 16.5%, bone proportion of 10.7%, lean meat percentage of 42.0%, and hind leg proportion of 28.3%.

　　5.3. Meat Quality Characteristics

　　　　Muscle pH (within 45 minutes) is 6.1, meat color score is 3, water loss rate is 11.26%, cooked meat percentage is 64.4%, muscle marbling score is 3. Main chemical components: moisture 74.35%, dry matter 25.65%, crude protein 23.05%, crude fat 1.37%, ash 1.19%.

　　6. Reproductive Performance

　　　　6.1. Sexual Maturity: Around 120 days for boars, 120.57 days for sows.   6.2. Breeding Age: In rural areas, boars and sows often begin breeding at 5–6 months; on large farms, they usually breed at 8 months and 60–70 kg.   6.3. Estrus Season: Year-round.   6.4. Estrus Cycle: About 21.9 days for multiparous sows, lasting 2.5 days.   6.5. Gestation Period (229 litters): Average 114.6 days, with 25.18% at 114 days and 22.55% at 115 days.   6.6. Milk Production: First-litter sows (20-day litter weight) produce 31.8 kg; multiparous sows produce a total of 458.44 kg of milk over 60 days of lactation under good nutrition, averaging 7.97 kg per day.   6.7. Litter Size:    Multiparous sows average 15.02 piglets per litter (n=293 litters); first-litter sows average 10.93 piglets (n=238 litters).   6.8. Piglet Survival (weaned at 60 days):    Multiparous sows average 11.30 surviving piglets (n=275 litters), with an 86.53% survival rate (n=271 litters); first-litter sows average 8.48 surviving piglets (n=232 litters), with an 84.73% survival rate (n=227 litters).

　　7. Feeding and Management

　　　　Farmers in the production region have extensive experience in selecting and managing Jiaxing Black Pigs. Local sayings include: “Sparse hair, white hooves, purple-red skin, tall legs, broad back, long body, wide forehead, delicate face, pink nose, ears level with snout, bamboo tail, clove teats — eats like a tiger in one go,” “A sow’s quality is seen in three generations, her performance in three litters,” and “Good breed, good pig; poor breed, poor pig.” The region places great emphasis on selecting phenotypes with high reproductive performance, especially those with many teats and large hindquarters, using long-term directional breeding methods to ensure the stability of the Jiaxing Black Pig’s high-yield genetic traits. In terms of management: Original breed farms house production boars and sows in single-row, semi-open pens with outdoor exercise yards. Gilts are kept in small groups, while sows and boars are housed individually. The main diet consists of complete compound feed supplemented with green fodder, fed in a wet-dry form three times daily. Smallholder farmers typically house pigs individually, mainly feeding them energy feeds such as corn, barley, and bran, with little use of complete feed. Sows are given larger amounts of green fodder, usually fed in a soup-like form three times a day. Both boars and sows of this breed are gentle, lazy, easy to train for the “three fixed” behaviors (feeding, drinking, and resting spots), and relatively easy to manage.