(I) Selection of gilt gilts should be selected from high yielding male and female sows, and the varieties must be pure. In addition, attention should be paid to the selection of gilts with more teats, and generally not less than twelve teats. (2) The so-called excellent feeding for the empty-feeding period is that the sow does not immediately cut off the feed after weaning, and it is still fed like a late lactation period; short-term supply of the amount of feed corresponding to the heavy-term period before mating is divided by 5 kg to 7 per day. In addition to 5 kg of green fodder, 2.5 kg to 3 kg of mixed concentrates can be fed. In this way, sows can generally be ovulated 2 or 3 times more. If you can grasp the timely breeding, you can make the conception rate increased by 8% to 10%. For empty sows, green feed containing protein and minerals should be fed to maintain a medium sensation. Adhere to the sow everyday to soak up the sun. (3) Quasi-distribution means timely mating according to the estrus law of the sow. Generally should be in May to 7 months of age, when the second and third estrus began to breed more timely. It is not good for gilts to be bred prematurely or too late. Sows usually begin ovulation on the second day of heat, lasting about 10 hours to 30 hours. The suitable time for breeding is: 2 days to 3 days after the start of the estrus of the soil type sow, and the cultivar of the outside species is on the day of estrus or the morning of the next day, and the hybrid is on the afternoon of the second day after the estrus. In terms of age, we should master the principle of "early match with early, small with late, not old with small". If you can repeat the breeding every 8 to 12 hours after the first breeding, you can further improve the conception rate and the number of litters. (IV) Pregnancy Management During the pregnancy, sows are to be raised in a single lap, and activities should be appropriately released. The feed is mainly fed with concentrates containing minerals such as protein and calcium, but it also feeds green and juicy green feed. Feed must be fresh, moldy or toxic feeds cannot be fed, sows are protected from poisoning, resulting in premature or miscarriage. In addition, appropriate blood and fetal drugs and calcium tablets should be fed properly. Don't overfeed your sow within one month before the sow gets pregnant so as not to crush the piglet. (e) Shortening the period of breast-feeding and prompting the sow to re-estrus prematurely: The piglets give birth for about 10 days and start to feed. By 1 month, the piglets can eat a lot of feed, and they can be weaned at 45 days to allow the mother to The pigs are estrus again, so that each sow can produce two litter piglets per year.