Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that these DEGs were significantly enriched in key inflammatory and immune regulatory pathways, including the TNF signaling pathway, C-type lectin receptor signaling pathway, Chemokine signaling pathway, NOD-like receptor signaling pathway, NF-κ B signaling pathway, and IL-17 signaling pathway, suggesting that these pathways play central roles in the mammary immune defense against E. coli infection. This evidence concerns the gene CLEC4D and escherichia coli infection.