Effects of Leptin and Thyroglobulin gene polymorphisms on beef quality in Holstein breed bulls in Turkey

The relationship between three single-nucleotide polymorphisms (SNP) markers and the beef quality of Turkish Holstein bulls (THB) was investigated. The markers in leptin (LEP) gene (E2JW and E2FB) and thyroglobulin (TG) gene (C422T) were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in one hundred THB. Texture, pH, and marbling score (MS) are three of the most dominating determinants of meat quality. In THB, the relationship between 3 SNPs and beef quality characteristics of musculus longissimus dorsi (MLD) was investigated. The mean pH value of the raw beef samples with the TG G422T CC genotype was 5.33 ± 0.30 on day 7 and 5.31 ± 0.32 on day 14. The mean pH value of the raw beef samples with the LEP E2JW AA and AT genotypes measured on day 7 and day 14 (P < 0.05) was significantly different. The beef of THB with the AA and AT genotypes seemed to have different texture values compared to cooked beef samples of the TT genotype on day 7 (P < 0.05). There were no associations between pH value, Warner-Bratzler shear force (WBSF) scores, and MS in the E2FB genotypes. Regarding the LEP E2JW/ LEP E2FB/TG C422T markers, THB with the AA/CT/CC genotypes were found to produce beef of higher quality compared to other genotypes.