BIOCHEMICAL POLYMORPHISM IN 5 PIG BREEDS IN SOUTH-AFRICA

Electrophoresis was used to study the genetic diversity within and bet ween five pig breeds (Large White, Landrace, Duroc, Wild pig and Chest er White) in South Africa. They were compared with regard to gene and phenotypic allele frequency differences at 11 protein and enzyme codin g loci. two monomorphic loci were identified namely haemoglobin and ce ruloplasmin. The average heterozygosity values ranged from 0.091 to 0. 381; the percentage of polymorphic loci ranged from 18.18 to 81.82 in the Wild pig and the Large White breeds respectively, and the mean num ber of alleles per locus ranged from 1.18 (Wild pig) to 2.91 (Landrace ). The genetic distance values were between 0.056 and 0.288; with the smallest distance between the Large White and the Landrace breeds and the largest distance between the Duroc and Wild pig. The results are d iscussed with specific reference to genetic divergence between breeds within this species where interbreeding often occurs.