Fermentation profile and nutritional value of sisal co-product silage (SC) subjected to seven treatments (additives), were evaluated. The SC was ensiled in natura and added with: soy meal, urea, wheat meal, palm kernel cake, A. sisalana dust, licuri cake and cottonseed cake. Experimental silos with capacity for approximately 15 kg of silage, were used. The silos were opened 60 days after ensilage process. It was used a completely randomized design with three replications. The SC in natura present low values of dry mater (DM) 12.3% and the additives increased dry matter silages, exception for urea. The SC silage additivated with soybean meal (pH 4.9) and palm kernel cake (butyric acid = 0.07% DM) differed, respectively, for pH and butyric acid, compared with in natura SC silage (pH = 4.1 and butyric acid = 0.03% DM). The addition of soybean meal, urea, cottonseed meal, wheat bran and palm kernel, increased crude protein (CP) of in natura SC silage. The NDF in silage increased with addition of cottonseed meal or palm kernel cake (60.1 and 66.2% DM) in relation in natura SC silage (42.9% DM). The in natura and additivated silages of SC were considered as good or excellent quality.