Breeding pig reproduction method and fine breeding system for breeding pig before hybridization

The invention provides a breeding pig reproduction method and a fine breeding system for a breeding pig before hybridization. The breeding pig reproduction method includes crossbreeding a Danish-American Landrace sow and a Danish-American large white boar to produce a Danish-American crossbred sow, placing a selected American Duroc boar into the fine breeding system for breeding, and crossbreedingfor more than two weeks to produce a re-crossbred commercial pig. The final re-crossbred lean meat type commercial pig has the advantages of fast growth, high lean meat percentage of a ketone body and high feed remuneration; the breeding pig is fed in the fine feeding system, and thus the disease probability of the breeding pig is reduced, and the physique of the breeding pig is enhanced; and thebreeding pig can be quickly discovered when or before the pig is sick, by reducing the illness time in time, the physique of the breeding pigs during crossbreeding is ensured, the sperm and egg havesufficient vitality, and th