MicroRNAs (miRNAs) are small endogenously expressed single-stranded RNAs that regulate gene expression post transcriptionally and shape diverse cellular pathways. miRNAs regulate a wide range of biological processes through the recognition of complementary sequences between miRNAs and their target genes. The present investigation aimed at determining in-silico the genetic variability of miRNA genes in some livestock and non-livestock species. Effects of single nucleotide polymorphisms (SNPs) in genes? 3'UTR on target gain/loss of human miRNAs were also explored. A total of twenty four mature miRNA sequences and genomic coordinates in three livestock [chicken (5), pig (1) and cattle (9)] and two non-livestock (human (6) and mouse (3)] species were retrieved from the miRBase 15 release. Computational scanning of polymorphisms in the miRNAs revealed 33 and 20 polymorphic sites in livestock and non-livestock species, respectively. Of this, 7 (chicken), 11 (cattle) and 2 (mouse) were located within the seed region. The de novo computational prediction revealed that SNPs rs1042725 (C/U) and rs1044129 (A/G) in genes? 3'UTR of human miRNAs positively influenced the target site thereby resulting in target gain. However, the effects of SNPs rs56109847 (A/G), rs28927680, rs12720208 (G/A) and rs5186 (A/C) were negative. The evolutionary tree showed that the relationship between miRNA consensus sequences of livestock (pig, chicken and cattle) was closer compared to non-livestock species (mouse and human), which could be implicated in morphological complexity among vertebrates. Although the function of miRNA is only beginning to be understood, future in-silico research evaluating the functional effect of miRNA in gene translation and subsequent biological pathways especially in livestock is of paramount importance; and this should be complemented with hypothesis-driven experimental studies to evaluate the phenotypic effect of identified miRNA genetic polymorphisms in animals.