Bovine CX3CL1 (C-X3-C motif chemokine ligand 1), also known as fractalkine, is a unique chemokine that belongs to the CX3C chemokine family, distinguished by having three amino acids separating the first two conserved cysteine residues. Unlike most chemokines, CX3CL1 exists in both a membrane-bound form and a soluble form, allowing it to function in both leukocyte adhesion and chemotaxis. In cattle (Bos taurus), CX3CL1 is primarily produced by endothelial cells, epithelial cells, macrophages, and other activated tissue cells in response to inflammatory cytokines or infection. CX3CL1 binds specifically to the receptor CX3CR1, which is expressed on monocytes, macrophages, natural killer (NK) cells, and subsets of T lymphocytes, promoting recruitment, adhesion, and activation of these immune cells at sites of inflammation or tissue injury. In bovine health, CX3CL1 contributes to immune responses during bacterial and viral infections, including inflammatory conditions affecting the mammary gland, respiratory tract, and other tissues, where leukocyte recruitment is essential for pathogen clearance. Because chemokine-mediated immune cell trafficking plays an important role in host defense and inflammatory disease in cattle, bovine CX3CL1 is studied in veterinary immunology, mastitis research, and host–pathogen interaction studies to better understand mechanisms regulating immune cell migration and inflammatory responses in livestock.