Cow　dung　possesses　potential　agricultural　and　energy　value　but　is　often　regarded　as　waste　and　underutilized　in　most　cases.　This　wastage　of　resources　not　only　poses　a　challenge　to　agricultural　sustainability　but　also　limits　economic　development　in　rural　areas.　Cow　dung　contains　natural　cellulose　components　like　cellulose　and　lignin　that　are　derived　and　used　to　prepare　fiber　materials.　This　paper　explores　a　potential　value-added　application　of　agricultural　waste,　i.e.,　cow　dung　fibers　to　reinforce　the　alkali-activated　slag　composites　(AASC),　which　are　fabricated　based　on　an　industrial　by-product　slag.　The　raw　and　alkali　treated　cow　dung　fibers　were　characterized　using　scanning　electron　microscopy-energy　dispersive　X-ray　spectroscopy　(SEM–EDS),　atomic　force　microscopy　(AFM),　X-ray　photoelectron　spectroscopy　(XPS),　thermo-gravimetric　analysis　(TGA)　and　X-ray　diffraction　(XRD).　The　porosity,　density,　water　absorption,　strength　and　drying　shrinkage　of　AASC　were　tested　and　used　to　evaluate　the　effect　of　alkali　treated　fibers　on　the　properties　of　AASC.　The　results　showed　that　subjecting　cow　dung　fibers　to　alkali　treatment　improved　their　surface　roughness　and　thermal　stability.　The　addition　of　cow　dung　fibers　led　to　an　augmentation　in　the　splitting　tensile　strength　of　AASC,　primarily　due　to　the　bridging　action　of　these　fibers.　In　particular,　the　28-day　splitting　tensile　strength　of　AASC　containing　1　wt%　of　untreated　cow　dung　fibers　increased　by　17.1%　over　the　reference　sample,　and　this　increase　was　more　pronounced　in　the　alkali　treated　fiber　sample.　Moreover,　the　alkali　treatment　effectively　reduced　the　effects　of　loss　of　compressive　strength　and　increased　drying　shrinkage　caused　by　fiber　incorporation.　The　findings　of　this　paper　are　helpful　to　solve　the　management　problems　of　cow　dung　waste,　reduce　the　environmental　burden　and　realize　the　value　utilization　of　resources.　©　The　Author(s),　under　exclusive　licence　to　Springer　Nature　B.V.　2024.