The formula of selection index and mating combination were mainly made by two characters, daily gain and backfat, and inbreeding coefficient of offsprings, respectively.
The formula of selection index and mating combination were mainly made by two characters, daily gain and backfat, and inbreeding coefficient of offsprings, respectively.
其选择指数公式的确立主要依据日增重，背膘厚这两个主选性状，选配计划的制订主要根据后代近交系数。