A deterministic modle was used to calculate the production efficiency (RMb/sow) of 64 possible mating systems involv Yorkshire, Landrace,Duroc and Hamshire.

• 应用确定性模型模拟了包含大白猪、长白猪、杜洛克及汉普夏共4个品系64个繁育体系的生产效率（每头母猪的利润）。