Genotyping of the ? – casein gene by PCR – RFLP (AcuI digestion) and its relationship to milk yield traits in Anatolian buffaloes, Murrah buffaloes, and their crosses

Abstract

The aim of this study was to investigate the polymorphism of the ? – casein gene (kappa casein, CSN3) in buffaloes and determine its effects on milk yield traits. Data were obtained from 2016 to 2019 from all animals in the ongoing Anatolian Buffalo Breeding Project. Genomic DNA was collected from a total of 209 buffaloes of different ages and sexes, namely 31 Murrah, 46 Anatolian buffaloes, and 132 of their crosses (Murrah × Anatolian). Genotyping of CSN3 gene by polymerase chain reaction–restriction fragment length polymorphism (PCR – RFLP) technique with restriction enzyme (AcuI) revealed three genotypes: AA (0.689), AB (0.282), and BB (0.028), and the frequencies of A and B alleles were 0.83 and 0.17, respectively. A total of 113 milk yield data and 74 milk component analyses of dairy buffaloes were used to compare CSN3 genotypes for milk yield traits. Statistical analysis showed that there was a significant difference in lactation milk yield between CSN3 genotypes: BB, 1560.3 ± 326.7 kg, AB, 1278.1 ± 111.3 kg, and AA, 1060.9 ± 85.6 kg (p < 0.05). However, the mean values of lactation length and milk components were not significant between genotypes (p > 0.05). These results suggest that these variations $(135^{ThrACC} / IleATC /136^{ThrACC} / ThrACT)$ in the buffalo CSN3 gene may be used as genetic markers in dairy buffalo breeding programs.