Tongcheng

Ecological Conditions: The Tongcheng Pig is mainly found in the highland region of Mufu Hill. The pig is also widely distributed in Chongyang, Puqi, Tongshan, Xianning and other counties of Hubei Province. Tongcheng County is adjacent to the Jianghan Campagna and the Dongting Lake, therefore it has mild weather, abundant rainfall, and large area of arenaceous soil (See the Figure 1. ,The rectangular area indicates the main distribution area of Tongcheng pig). The total land area is 320,000 acres. Crops are planted in two or three periods each year, with rice paddy fields taking up 87% of the land area. Other crops grown include sweet potato, rape, soybean and corn. The mountains, offer an abundance of vegetation, which together with agricultural by-products provide convenient conditions for pig production. Tongcheng pigs have been selected gradually over time by the local people. The animals are reared in pens and are provided with cooked food. According to classification of Pig Breeds in China, Tongcheng Pig was classified as Central China type (Zhang et al, 1986).

Appearance characteristics: Tongcheng Pig is also named "Two Ends Black" because it has a characteristic black and white hair colour pattern. The hair on the head, neck and stern tail end is black. There is a small area of white hair on its head, which is called "White Star" by local people. Some animals have white hair extending from head to nose point, and are referred to as "Broken Forehead". The head is medium in size with several deep wrinkles on the face which look like the Chinese word "CDF294 (Ten thousands), while in some looks like the Chinese word "D2BB94 (One) because of its deep lateral wrinkles on the forehead. The nose is commonly pale red, called "cuticolor mouse", but in some animals it is black, hence they are referred to as "iron mouse". The ears are dropping, the neck is moderate in length and links to the shoulder tightly. The four limbs and trunk are covered by white hair. Some animals have a black or several black cob spots on the trunk, which is called "waist flower" or "back flower" depending on its position. The back and waist are sunken, except in a few individuals. The abdomen is big and dropping and most of sows walk with their teats touching the ground. The hip is sloped, the color of skin covered with white hair is mostly pale red. It has straight forelimbs and bent back limbs.

Production Performance: Tongcheng pigs reach sexual maturity at a relatively early age. Boars exhibit initial "sexual behavior" at about 40 days of age, and are able to mate from 100 days of age. However, they are considered suitable for first mating at 6-8 months of age when they weight 40-50kg. First oestrus in gilts occurs at 90 days of age; however, they are first mated between 180-240 days of age, when they weight 45-50 kg. The average litter size of first, second and third furrowing is 6.9, 8.6 and 11.07 respectively.

The hogs grow fast, and attain an average body weight of 80.10 kg at six months of age, under the local climatic and feeding conditions. The meat is delicate fresh and tasty. Results of performance testing of carcass traits in 30 slaughtered Tongcheng pigs are as shown in Table 1.

Table 1: The performance testing data of Tongcheng pigs

From a livestock breed evaluation meeting held in Wuhan city in 1984, Tongcheng pigs had the highest meat quality score for its beautiful color, refreshing taste and excellent configuration relative to Landrace, Large-Yorkshire, Middle Yorkshire among other breeds.

Breed Utilization:

1. Breeding Stock: The Tongcheng pigs have a long history and stable inheritance. The boars of 15 different bloodlines are kept in Tongcheng County. The sire bloodlines are sufficient to avoid inbreeding depression and are used to improve the performance and maintain the purity of the breed while retaining its excellent traits. Tongcheng pigs are also used as special breeding material for the development of new breeds. For example, in the 1980's, Huazhong Agricultural University and Hubei Research Institute of Animal Husbandry and Veterinary Medicine, developed the famous breed, "Hubei White Pig" through a three-way crossbreeding using Tongcheng sows as terminal female parent (Peng et al, 1994; Xu et al, 2001).

Since 1980, hybrid offsprings from two and three-way crosses using the Tongcheng breed have shown remarkable heterosis on growth and reproduction performance (Xu et al, 2001). The mode of crossing was as follows: Tongcheng pigs were used as dams on commercial breeds, such as Large Yorkshire, Landrace and Middle Yorkshire sires. Huazhong Agricultural University in collaboration with Tongcheng County livestock breeding farm, developed a new cross "Landrace × Large White × Tongcheng", i.e. Tongcheng used as sows and mated with Landrace and Large White in turns. This kind of cross is noted for its excellent meat quality and relative high growth rate, and is named "E Qing Yi Hao".

2. Breed Conservation A Tongcheng pig conversation farm was established for maintaining the pure breed of Tongcheng pigs in Tongcheng county, which is partly supported by the Ministry of Agriculture of China. Protection and preservation of the Tongcheng pig are also carried out in villages of the mountain area of Tongcheng County. To maintain the integrity of the breed, the area is closed to imports of other pig breeds. Different mating groups are maintained, and artificial insemination (AI) is used. To reduce inbreeding, boars are used in a rotational system between different breeding groups.

Evaluation of the genetic diversity: Li X M et al (2000) analyzed the genetic variation of the Tongcheng breed with four microsatellite markers, all the markers were polymorphic. The observed heterozygosity and polymorphic information content were 0.7124 and 0.6717 respectively. Li K et al (2000) studied the genetic variation of Tongcheng breed with a set of 27 microsatellite markers recommended by the Food and Agriculture Organization of the United Nations and International Society of Animal Genetics (FAO-ISAG). All the markers were also polymorphic. The result of clustering with four other indigenous pig breeds showed that Tongcheng had closest genetic relationship with the Qinping breed.

Reference

1. Editorial Committee of the "Breeds of domestic animal and poultry in Hubei Province". Breeds of domestic animal and poultry in Hubei Province. 1985,pp33-42.

2. Li K, Y. Chen and C. Moran et al., Analysis of diversity and genetic relationships between four Chinese indigenous pig breeds and one Australian commercial pig breed. Animal Genetics, 2000, 31:322-325.

3. Li X.M., Z.X. Gu and K. Li, The genetic diversity of ten pig breeds in China by means of four microsatellite loci, Journal of Shandong Agricultural University (Natural Science), 2000, 31(3) 261-264.

4. Peng Z.Z., Pig Genetics and Improvement. Chinese Agricultur Publishing house, 1994, pp237.

5. Xu S.P. and Wu P.B., Conservation and breeding of Tongcheng Pig. Hubei Animal Husbandry and Veterinary, 2001, 5: 17-19.

6. Zhang Z.G., B.T. Li, X.H. Chen, Pig Breeds in China. Shanghai Scientific and Technical Publishers. 1986, pp75-81.