Abstract:
Background DNA methylation is an epigenetic mechanism that takes place at gene promoters and a potent epigenetic marker
to regulate gene expression.
Objective The study aimed to improve the milk production of Zaraibi goats by addressing the methylation pattern of two
milk production-related genes: the growth hormone receptor (GHR) and the growth diferentiation factor-9 (GDF-9).
Methods 54 and 46 samples of low and high milk yield groups, respectively, were collected. Detection of methylation was
assessed in two CpG islands in the GDF-9 promoter via methylation-specifc primer assay (MSP) and in one CpG island
across the GHR promoter using combined bisulfte restriction analysis (COBRA).
Results A positive correlation between the methylation pattern of GDF-9 and GHR and their expression levels was reported.
Breeding season was signifcantly efective on both peak milk yield (PMY) and total milk yield (TMY), where March
reported a higher signifcant diference in PMY than November. Whereas single birth was highly signifcant on TMY than
multiple births. The 3rd and 4th parities reported the highest signifcant diference in PMY, while the 4th parity was the
most efective one on TMY.
Conclusion These results may help improve the farm animals' milk productive efciency and develop prospectiv
