Ecological condition: The Taihu pig mainly found in the Taihu valley, which borders Jiangsu Province, Zhejiang Province and Shanghai City. The local natural environment, social economic conditions and the farming system, have played an important role in the formation of Taihu pig's characters. Located in subtropics, the mild climatic conditions of adequate rainfall that result in high crop yields make this place one of the most famous agricultural areas in China. All these factors promote the increasing development of pig breeds. Because of the high population density in the area, pigs are kept in enclosures all the year round. Their diet mainly constitutes barley and rice bran. The succulenct feeds comprise radish, pumpkin, green grass and marine lives. These feeds contain more phosphorus and less calcium thus limiting bone development although good for the development of sex organ. The high standards of living of the affluent people have resulted in high demand in meat quality. These factors combined have led to development of the Taihu Pig which has high prolificacy, juicy and tasty meat quality [See photographs].
The Taihu Pig can be classified into many types i.e, Erhualian, Meishan, Fenjing, Jiaxing Black, HengJing, Mi pig and ShaWuTou pig etc. This is due to the variability in character and performance, as well as the regions of sow breeding centers. The Erhualian pigs are mainly found in the counties as JiangYing, WuJin, WuXi, and ChangShu. Meishan pigs are distributed in JiaDing of ShangHai city, TaiCang and KunShan of JiangSu province. FengJing pigs are predominant in JinShan, SongJiang, and WuJiang. JiaXing black pigs are found in the suburb of JiaXing, Jiangsu province. HengJing pigs are distributed in HengJing Town of Wu county, Jiangsu province. Mi pigs are distributed in JinTan and Yangzhou, JiangSu province while ShaWuTou pigs mainly dominate QiDong and HaiMen, JangSu province. According to classification of Pig Breeds in China, Taihu Pig was classified as Lower Changjiang River Basin type (Zhang et al, 1986).
Appearance characteristics: Taihu Pig has medium body size, but varies among the different types. For example, Meishan pigs have relative large body and strong bone compared to the subtle bone of Mi pig. Erhualian, Fengjing, Hengjing and Jiaxing Black fall in between while ShaWuTou has a compacted body. Taihu Pig has big head, wide forehead that has thick and wrinkled skin. They have big droopy ears with leveled ear tine (the ear looks like punkas) and overlapping mouth corner. The body is covered with black coat, which is sparse and flocky, with large differences between each flock. The skin under the belly is purple-red, nose and tail tine in some pigs are white. The limbs of Meishan pig are white, and so its name "four white feet94. They have 8-9 pairs teats. The body weight, length, height and Breast circumference at 6 months is 47.5kg, 94.7cm, 51.1cm and 80.7cm, respectively. Of all the Taihu Pigs, Meishan pigs have the largest body size, the other breeds show slight differences.
Production performance: Taihu Pig is famous for its high prolificacy in the world, and it is one of the most prolific pig breeds in the world. According to statistics, its litter size at first, second and the third farrowing is 12.1, 14.4, and 15.8, respectively. The high prolificacy of Taihu Pig has a close relationship with the early development of sex organs and sex ability. According to the reported results, the days boar semen appears are as follows: Erhualian 56-66 days; Jiaxing Black 74-77 days; Meishan 82 days; Fengjing 88 days; The first time when the semen has sperm is as follows: Erhualian 60-75 days; Jiaxing Black 77-79 days; Erhualian Pig can produce normal semen at 90 days when they grow to 4-5 months, and the quality of semen can reach the level of mature boars. The average ovulation numbers of adult sow are 21.98 (Chu et al, 2003).
Under good feed condition, the average daily gain of Taihu Pig is between 400g and 500g. According to the experiment of Jiading pig breeding farm , the average daily gain of Meishan pig is 466g, the F/G are 3.997:1, the dressing percent is 66.24%, lean percent is 44.11%, intramuscular fat content is 3.27% (Chu et al, 2003).
1. Crossbreeding The Taihu Pig is widely used as a dam breed for mating with Yorkshire, Russia white and Landrace boars. Hybridization with introduced commercial boar affects its reproduction ability. The survival rate, rearing rate, litter weight at birth and weaning weight could however be improved. During the cross-breeding of barrows, the parent breed chosen as a sire line depends on the feed conditions. Under low levels of feeding, Yorkshire is the suitable sire breed while under moderate feeding condition, Russia white would be suitable. Under the best feeding condition, Landrace can be used as a sire breed. The hybridization offspring have highly growth rate, high feed efficiency and high lean meat mean percentage.
Systematic selection for lean meat and crossbreeding of the original Taihu pig, and Duroc, resulted in development of a new Taihu Pig, the new lean type breed. It performs well as a dam breed for commercial lean type pig production. In the nuclear breed, the litter size of multiparous sows is about 15.67 on average; the litter size of procreative sows is 14.15, having 8-9 pairs of teats. New Taihu pig has the following characteristics, the body weight length, height, breast circumference and breech width at 180 days is 85.6kg, 112.50cm, 56.23cm, 99.12cm, 25.83cm, respectively. Live backfat thickness at 80kg is 1.83cm, the lean percentage in carcass is 54.31%, and feed per kg gain is 3.19:1. Compared to the original Taihu pig, the lean percentage increased by 12% and the growth rate increased by 83.66%.
2. Conservation of Taihu pig In Jiangsu province, Zhejiang province and Shanghai city, there are 28 state-owned breeding farms, over 200 prefecture breeding farms, which raised 10 thousands Taihu Pigs in total. There are 320,000 Taihu sows in Jiangsu province which is 20% of all sows raised in the province. The Taihu pig breeding committee in Jiangsu, Zhejiang and Shanghai organize annual recording of well-bred Taihu pig and evaluation of Taihu pig breeding farms is carried out after every two years for excellence. Owing to the recording and evaluation of the breeding farms, there are three to four sire lines of candidate boars and 40-50 nuclear herd sows in every farm.
Evaluation of the genetic diversity: Fan et al(2002) studied the genetic variation of Erhualian, Small Meishan, Middle Meishan, Mi pig and Shawutao groups of the Taihu 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-ISGA). All of these markers were polymorphic. Average observed alleles at all loci were 5.741, 5.111, 3.703, 5.333, and 4.333. The mean effective alleles were 2.918, 2.895, 2.045, 2.901, 2.906, the observed heterozygosity were 0.522, 0.488, 0.332, 0.497, 0.519 and the expected heterozygosity were 0.621, 0.603, 0.429, 0.623, 0.605. When clustered with other breeds from Lower Changjiang River Basin type, the five breeds formed a branch.
1. Chu M., C. Wu and J. Zhang, The studies and application of high reproduction ability of Taihu pigs. The Press of Chinese Agricultural Science and Technology, 2003, 1-196.
2. Fan B., Z.G. Wang and Y.J. Li, Genetic variation analysis within and among Chinese indigenous swine populations using microsatellite loci. Animal Genetics, 2002, 33(6), 422.
3. The Breeding Committee of the Taihu. Chinese Taihu Pig. Shanghai Scientific and Technical Publishers.1991.
4. Zhang Z.G., B.T. Li and X.H. Chen, Pig Breeds in China. Shanghai Scientific and Technical Publishers. 1986 pp131-135.