First, strengthen the sow's feeding and management in the empty period of the sow, during the second trimester of pregnancy and late lactation feeding more raw materials, appropriate feeding green materials; early pregnancy, late and early lactation sufficient supply of protein, minerals and vitamin-rich essence Materials and green and juicy feed, at the same time to provide a relatively stable living environment for sows, as far as possible to reduce the crowd, drive away, fighting and other external stimuli. Second, reasonable arrangements for the sow breeding season best choice in April - May breeding, September - October breeding again, and repeated cycles, so that the sows can be mated in the spring and fall breeding, avoid the cold And hot summer and summer environment. Third, the timing of mating from the sow's physiological age, should be "old with early, small with late, not the old with the middle." Under normal circumstances, 19 hours to 30 hours after the estrus estrus, the swollen genitals of the sows just begin to subside, and there is filamentous mucus outflow, and the sows can be properly bred when the sow is hindquartered. Sows are to be bred at seven months of age, eight months of age, and a weight of more than 100 kilograms. IV. Breeding methods and artificial insemination Both the present and the artificial insemination must be used in the double match (ie, the first time when waiting for match reaction occurs, and the second time after 12 hours interval). This can significantly increase the conception rate and the number of litters. Using artificial insemination technology, semen of healthy elite boars must be used. Each milliliter of semen requires more than 40 million spermatozoa with a sperm viability above 0.6. The device should be strictly sterilized. First wash the genital area of ​​the sow with 0.01% KmnO4 solution. Then insert the vas deferens slowly into the cervix about 20 cm - 30 cm. Then connect the insemination syringe and slowly inject 20 ml of semen. Hours of infusion again. Fifth, to strengthen the fetal protection measures 9 days after sow breeding - 13 days and easy to abortion 21 days before delivery, should particularly strengthen the fetal protection measures, try to supply protein, minerals, vitamins and other rich fine material and green juicy feed, Do not feed frozen and mildly rotten feed. Pregnant sows try to avoid mechanical irritations such as crowding, biting, slipping, whipping, scaring and so on. Farm breeding must have detailed records to avoid inbreeding. The prevention of epidemic diseases must be carried out in pigs, especially the prevention of type B epidemic encephalitis, influenza, brucellosis and other diseases, and timely treatment of diseases should be found. Pregnant women with abortion should not be immediately injected with progesterone 15 mg - 25 mg, and take sedation orally to stabilize the fetus.