Bovine IL-17F (Interleukin-17F) is a pro-inflammatory cytokine belonging to the IL-17 family that contributes to host defense and inflammatory responses in cattle (Bos taurus). IL-17F is produced primarily by Th17 CD4⁺ T cells, as well as by γδ T cells—which are abundant in ruminants—and other innate lymphoid cell populations in response to microbial infection and inflammatory stimulation. It signals through the IL-17 receptor complex (IL-17RA/IL-17RC) to induce expression of pro-inflammatory cytokines, chemokines such as CXCL8, and antimicrobial peptides, thereby promoting neutrophil recruitment and enhancing mucosal barrier immunity in respiratory, gastrointestinal, and mammary tissues. In healthy cattle, basal IL-17F expression is generally low but increases during bacterial and fungal infections, mastitis, respiratory disease, enteric infection, and parasitic challenges. IL-17F often acts in concert with IL-17A to amplify neutrophilic inflammation and mucosal defense. In veterinary and agricultural research, bovine IL-17F serves as a biomarker of Th17-mediated immune activation and is studied in the context of vaccine responses, host–pathogen interactions, and inflammatory disease mechanisms affecting cattle health and productivity.