sire line
1.On the basis of breeding new strains A、 B、 C and purely breeding Duroc、Yorkshire、 Landrace, selection and breeding of "Huate" best-hybridized combination werecarried out in 1991. Duroc is ideal sire breed, strain A 、 B and C would be dam line of sire line,sire line of dam line and darn line of dam line.
