The crucial genetic factors of live weight inheritance including breeding value, dominance deviation, heritability and heterosis had not been studied in Ongole-grade cows. This study aims to identify the genotypic components including breeding value, dominance deviation, heritability and heterosis of live weight trait in Ongole-grade cows. A total of 78 blood samples from parental cows and 2 blood samples from parental Ongole-breed bulls were collected to be analyzed for presences of growth hormone (GH) genes. Presences of GH locus in blood samples were screened using PCR-RFLP method involving restricted enzyme Msp1 on agarose-gel (1.2%). Data were analyzed by statistical program in Excel XP. Results showed that the population mean (μ) of cow live weight was 385.98± 2.49 kg. Genetic component inheritance of homozygous genotypes of GH +/+ and GH –/– and heterozygous genotype of GH +/– were dominated by dominance gene action, rather than the additive gene action resulting the valuable heterosis for live weight trait of 3.2 percent. The heritability of dominance gene action (hD 2 ) was 0.96 categorized as higher heritability, while heritability of additive gene action (hA 2 ) was 0.04 categorized as low heritability under the equilibrium frequencies of both GH + (p = 0.48) and GH – (q = 0.52) genes without considering the nongenetic causes of environmental effect in the population of cow live weight.