Bovine CXCL13 (C-X-C motif chemokine ligand 13), also known as BCA-1 (B-cell–attracting chemokine 1), is a homeostatic chemokine belonging to the CXC chemokine family that plays a critical role in B-cell migration and lymphoid tissue organization. In cattle (Bos taurus), CXCL13 is produced primarily by follicular dendritic cells, stromal cells, and macrophages within secondary lymphoid tissues such as the lymph nodes, spleen, and Peyer’s patches. CXCL13 signals through the chemokine receptor CXCR5, which is expressed on B lymphocytes and subsets of T follicular helper (Tfh) cells, directing their migration into lymphoid follicles and germinal centers where antibody responses are generated. In bovine immunity, CXCL13 plays an important role in B-cell homing, germinal center formation, and development of humoral immune responses during infection or vaccination. This chemokine is particularly relevant in immune responses against bacterial and viral pathogens affecting cattle, including those associated with bovine respiratory disease and gastrointestinal infections, where effective antibody production is essential for pathogen clearance. Because CXCL13 regulates B-cell trafficking and lymphoid tissue architecture, bovine CXCL13 is studied in veterinary immunology, vaccine response research, and host–pathogen interaction studies to better understand mechanisms controlling humoral immunity and lymphoid organ function in cattle.