Bovine Interleukin-16 (IL-16) is a proinflammatory cytokine that plays an important role in regulating immune cell recruitment and activation in cattle (Bos taurus). IL-16 is produced by several cell types, including CD8⁺ T cells, eosinophils, mast cells, and epithelial cells, and is released in response to immune stimulation or inflammatory signals. Bovine IL-16 functions primarily as a chemoattractant for CD4⁺ immune cells by binding to the CD4 receptor, promoting migration and activation of T helper cells, monocytes, and dendritic cells to sites of infection or inflammation. Through these actions, IL-16 contributes to coordination of immune responses and modulation of inflammatory signaling. In cattle, IL-16 is involved in immune responses against bacterial, viral, and parasitic infections and may influence inflammatory processes in tissues such as the respiratory and gastrointestinal tracts. In cell culture, recombinant bovine IL-16 is used to study chemotactic responses of CD4⁺ immune cells, investigate mechanisms of immune cell recruitment and activation, and evaluate cytokine-mediated regulation of inflammatory pathways. Due to these functions, bovine IL-16 is studied in veterinary immunology and translational research, including investigations of host–pathogen interactions, inflammatory disease mechanisms, and immune regulation relevant to livestock health and comparative biomedical research.