Reserve sows are selected according to parental generation and development.

The selection of reserve sows depends on the production performance of the parents of the reserve sows: the breeding boars of the parents should grow and develop well, the feed reward is high, the lean meat rate is high, and there is no genetic disability; the breeding sows of the parents should have more offspring, strong lactation, good motherhood, large litter size and significant birth weight. Second, piglets should select piglets with large birth weight, good growth and development, fast and strong weight gain, heavy weaning body, neat and uniform arrangement of nipples above 14, and no major defects in appearance. Third, after the reserve sows are sexually mature, the final selection of normal estrus, obvious signs, limbs, nipples, growth rate and backfat thickness in line with the characteristics of the breed will be reserved for breeding.