There are many excellent germplasm characteristics of local pig breeds in China, the most important of which are: high fertility, good meat quality, and strong stress resistance. 1) High fertility Chinese local pigs are sexually mature. Jiaxing black pig, Erhualian pig, Jiang Quhai pig, Neijiang pig, Chenghua pig, Dahua white pig, Northeast human pig, Jinhua pig, Daweizi pig and other 9 varieties, sow average age 94.4 days, average weight 22.7 Kg; The average age of sexual maturity is 129.5 days, of which the US Qu Hai pigs are 76.7 days old; while the ectopic periods of the foreign pig breeds Landrace and Duroc sows are 173 days and 224 days, respectively. The first occurrence of spermatozoa in boar semen was much earlier than that of foreign pigs. For example, Daihuabai pigs were 62 days old, Daweizi pigs were 75 days old, and foreign pigs were more than 210 days old. The number of ovulation in the local pig breeds in China was 15.4 for the average production of the above nine varieties, and the yield was 20.7, which was higher than that of foreign varieties. The number of litters produced in Chinese local breeds is high. The average yield of the above 9 varieties was 10.4, and 14.2 were produced. The world's highest-produced Taihu pig has produced 13.5 pigs, produced 16.7 pigs, and had 8-9 pairs of sow teats. Among breeders of high fertility, Landrace Pigs, Yorkshire pigs have 10-11 pigs and 6-7 pairs of teats. The number of farrowing herds is a low heritability trait and the selection and breeding of this breed is basically ineffective. Therefore, advanced pig raising countries such as the United Kingdom, the United States, France, and Japan are competing to introduce Taihu pigs and domestic pigs to hybridize with domestic breeds in order to use the pig breeds in China. High-yielding genes. Compared with foreign pig breeds, China's local pig breeds also have the characteristics of obvious estrus, high conception rate, less postpartum disease, high milk yield, good maternity (no pressure), and high piglet rearing rate. 2) Good meat quality Some highly cultivated lean meat breeds and strains abroad have the advantages of fast growth, high feed conversion rate, and high lean meat yield. However, the meat quality is not good, PSE meat (flesh gray, soft texture, water seepage The high incidence of poor quality meat has caused the pig industry to suffer huge economic losses. Meat quality improvement has become the focus of current pig breeding work. The meat quality of local pig breeds in China is significantly better than that of foreign pig breeds, including domestic pigs, Jinhua pigs, Jiaxing black pigs, Erhualian pigs, Jiang Quhai pigs, Neijiang pigs, Dahuabai pigs, Xiang pigs, and Daweizi pigs. The flesh color is bright red and there is no grayish white meat; compared with the meat quality of the control varieties (Landrace, Yorkshire, etc.), the muscle system has good water power, the water loss rate (%) is 6.8 on average, and the pH is more than 6. l, which is higher than the control pigs. High 0.4; Muscle marble distribution is uniform and moderate; Muscle dry matter percentage is 2.8, Intramuscular fat percentage is high 1.8 (of which the intramuscular crude fat of the pig is the highest, up 6.1%), and the muscle fiber diameter is 18.4% smaller than the control pig. The number of muscle fibers per unit area was 34.7%. All of these excellent meat quality traits have formed Chinese local pig breeds with fine meat quality, succulent meaty flavor and good palatability. This will become a major advantage of China's pork competition in the international market. 3) Strong resistance The local pig breeds in our country have developed a good adaptability to the bad environment in the long-term natural selection and artificial selection of varieties. Under extremely poor climatic conditions and feeding conditions, Minzhu, Jiang Qu Hai Pig, Neijiang Pig and Erhualian Pig. Dahua White Pig, Jinhua Pig, Daweizi Pig, and Hetao Big Ear Pig have stronger resistance to stress than White Harsh Pig and Landrace Pig, and they are mainly characterized by: cold resistance, heat resistance, resistance to rough feeding, and hunger tolerance (to low Nutritional tolerance is strong and can adapt to high altitude ecological environment. These characteristics of local pig breeds in China are valuable genetic resources for pig breeds. The first task of raising pigs is to preserve the seeds, and the second is to develop and use them so as to prevent the extinction of breed resources and bring into play the unique role of each pig breed.
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