Polymorphisms of pyruvate carboxylase gene (rs133566428) and its effects on economic traits in Holstein cows

• Waleed Ahmed Mohammed1, Hameed Razzak Al-janabi2, Tahreer Mohammed Al-Thuwaini1*

  Author

A genetic selection strategy can be improved by identifying candidate genes and variants associated with economically important traits in dairy cattle. Specific genetic markers linked to traits such as milk production, fertility, and disease resistance can be pinpointed. The study was conducted at the Greater Diwaniyah Dairy Station in Diwaniyah Governorate during the 2023–2024 production season to investigate the effect of the Pyruvate Carboxylase (PC) gene variant rs133566428 on milk production, milk components, and reproductive traits in Holstein cows in Iraq. The study involved 50 cows aged three to five years, all maintained under identical feeding and management protocols. Each cow completed a lactation period of 305 days. Genotyping was performed to determine genotypes and allele frequencies. Sequence analysis of 816 bp amplicons identified a single nucleotide polymorphism (SNP), rs133566428. The results showed three genotypes of the PC gene: GG, GA, and AA. There were statistically significant differences (P ≤ 0.01) among the genotype frequencies: GG 16.00%, GA 16.00%, and AA 68.00%, respectively. The results showed a significant effect (P ≤ 0.05) of the GG and AA genotypes on total milk production of 4191.25 ± 414.89 kg and 4112.88 ± 296.92 kg, respectively, compared to the GA genotype, which produced 3276.25 ± 344.08 kg. The PC gene polymorphism had no significant effect on reproductive traits and milk components, except for fat percentage. It can be concluded that there is a statistically significant association between the PC gene and milk production, indicating its potential use for genetic improvement in dairy cattle; however, a larger sample size and a greater variety of cattle breeds are essential to validate the results.                                                                                                                                

• pdf