Zoology environment: The central production areas of Rongchang Pig are Rongchang county of Chongqing and Longchang county of Sichuan province. It is also distributed over the nearby Yongchuan, Lu county, Luzhou and Hejiang. The main production areas are found southeast of Sichuan basin, where the altitude is 315~500 meters. It has a mild climate with average temperature of 18ºC. There is adequate rainfall and many rivers that facilitate irrigation. According to classification of Pig Breeds in China, Rongchang Pig was classified as Southwest China type (Zhang et al, 1986).
Appearance characteristics: Rongchang Pig is big, it has an average-size head, concave and wrinkled face, big and drooped ear and vertical hair. It has a long body, concave back, tilted haunch and a big belly. Its limbs are well developed and strong. The hair is all white except for the head which has some black spots. Its bristle is white, glossy and rigid with average length of between 11 and 15cm. A pig can produce bristle 200~300g each year with net bristle production rate of 90%. Females have teats which range from 6 to 7 pairs.
Production Performance: Rongchang pig matures very early. Sows reach puberty at 85.7(71~113) days of age. The average age at first mating is about 4~5 months, but the appropriate mating time is at 7~8 months when they weigh about 50~60 Kg. The litter size born, the litter weight, individual weight, number of weaned, weaned litter weight and the weaned individual weight of first parity are 8.56, 6.21Kg, 0.772Kg, 7.64, 76.62Kg and 11.03Kg, respectively while the corresponding indices for later parities are 11.7, 9.12, 0.855, 9.66, 113.82 and 11.85, respectively. Under the nutritional level of 7.4MCal(DE) and 291g (DCP), an average daily gain of 623g was attained in pigs with initial weight of 14.74 kept for 121 days on the diet. The appropriate period for slaughter is 7~8 months when body weight is about 80Kg. The dressing and lean meat percentage are 69% and 42~46%, respectively (Zhang et al, 1986).
1. Crossbreeding Rongchang sows are used for crossbreeding with Yorkshire, Berkshire and Landrace boars. Landrace × Rongchang breed combination has proved to be the best for selective breeding because of a high ADG and feed conversion efficiency of the crossbred offspring ranging between 14~18% and 8~14%, respectively. When Rongchang sow was crossbred to Hampshire and Duroc boar, carcass lean meat percentage of F1 offspring were 57% and 54%, respectively. Used as a sire line, on Beijing Black sows, Rongchang boars produce F1 offsprings with ADG and feed conversion rate of 12.2% and 2.4%, respectively.
2. Consevation of pure-breed The conservation work of Rongchang pig had been undertaken by Chongqing Swine Science Academy. Now, there are 18 pedigrees and 200 breeding pigs. In situ utilisation and Cryopreservation of embryos have been considered for conservation, however, under practical condition, in situ utilisation is often adopted as the primary method.
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