Project description:We investigated miRNA expression in Holstein dairy cow of mammary gland with different producing quality milk using high-throughput sequence and qRT-PCR techniques. miRNA libraries were constructed from mammary gland tissues taken from a high producing quality milk and a low producing quality milk Holstein dairy cow, the small RNA digitalization analysis based on HiSeq high-throughput sequencing takes the SBS-sequencing by synthesis.The libraries included 4732 miRNAs. A total of 124 miRNAs in the high producing quality milk mammary gland showed significant differences in expression compared to low producing quality milk mammary gland (P<0.05). Conclusion: Our study provides a broad view of the bovine mammary gland small RNA expression profile characteristics. Differences in types and expression levels of miRNAs were observed between high producing quality milk and a low producing quality milk Holstein dairy cow