Discipline: Animal Science
Protein/isozyme analysis using starch gel electrophoresis of 346 beef cattle plasma/serum samples was conducted to evaluate genetic diversity among beef cattle populations of Pangasinan, Tarlac, Romblon, Siquijor, Sorsogon, Cebu, Bohol, Negros and Batangas (pooled with Cavite and Laguna populations). Except for albumin (Alb) with one genotype AA, all of the seven loci, namely, transferrin (Trf), with six genotypes (AA, AB, AC, BB, BC and CC), three loci for esterase (Est1, Est2 and Est3) each with three genotypes (AA, AB and BB), two loci for acid phosphatase (Acph1 and Acph2) with six genotypes AA, AB, AC, BB, BC and CC) and five genotypes (AA,AB, AC, BB and BC), respectively and malate dehydrogenase (Mdh,) with four genotypes (AA, AB, AC and BB) were polymorphic. The proportion of polymorphic loci was 50-87.5% and the average number of alleles was 1.7143 to 2.2857. These were highest in Cebu, Bohol and Negros and lowest in Pangasinan and Siquijor. The beef cattle populations of Batangas and Sorsogon showed the highest degree of relatedness, hence shared the most common alleles as indicated by its low genetic distance of 0.0088. The genetically distant relationship between populations of Siquijor and Cebu based on genetic distance value of 0.3799 and the two separate groups based on the dendrogram, PCA and analysis of populations admixture conform with the microsatellite data of Aquino et al. (2004) which identifies Siquijor cattle as taurine type and Bohol cattle, a group closely related to Cebu cattle as predominantly Bali type.