Characterization of the Philippine native pig (Sus scrofa L.) based on phenotype, karyotype and protein polymorphism

Documentation of the phenotype of 19 male and 21 female native pigs kept in confinement and fed with standard ration showed that black was the predominant coat color pattern (85 percent), varying from pure black (40 percent), or with white spots on the face, hocks and tail (32.5 percent), or white underline (10 percent). Rust-brown (7.5 percent) and light brown with black spots (10 percent) were also observed. Body weight (BW) increase with age, from 4.62 kg (12 wk old) to 36.83 kg (32 wk old); females were heavier than males at 26-32 wk. Average daily gain (ADG) was lowest at 30-32 wk old (.18 kg), highest at 18-20 wk old (.27 kg); females 26-30 wk of age had higher ADG. Body length and heartgirth consistently increase with age, but tapered off from 28 wk onwards at which age females had longer body and bigger heartgirth. Backfat became thicker with increasing LW. Cultured leucocytes of 10 male and 10 female native pigs showed a total genomic complement of 2n = 38 [(18)II + XX (female) or XY (male)]. Autosome pairs were grouped into five submetacentric, two subtelocentric, five metacentric and six telocentric. The X-chromosome is meta-submetacentric while the Y-chromosome, smallest in the complement, is metacentric. G-banding technique revealed that bands in the native pig chromosomes agreed with those of domestic pigs. Starch-gel electrophoresis using blood serum from 100 native pigs showed that Tf and Akp loci were polymorphic while Alb and Es-1 were monomorphic. At the Tf locus, four bands were observed, inferred to be genes A, B, C at frequencies 0.295, 0.465, 0.240, respectively. Genotypes TfAA, TfAB, TfBB, TfBC, TfAC at frequencies 0.09, 0.23, 0.20, 0.21, and 0.27, respectively were observed. Homozygous genotypes had two bands, heterozygotes had three. At the Akp locus, three banding paterns of presumptive genotypes Akp AA, Akp AB and Akp BB at frequencies 0.45, 0.19, and 0.36, respectively were observed. Homozygous Akp had one band; heterozygotes had two. Based on the four loci studied, average heterozygosity was 22 percent