Fermented rapeseed meal has the potential to replace enzymatic and pro- and prebiotic additives, organic acids, and zinc oxide in diets for piglets. The aim of the study was to analyse the effect of rapeseed meal fermented using Bacillus subtilis strain 87Y (FRSMb) in the amount of 8% of diets for weaners on growth performance, digestibility of nutrients and minerals, and the amount of biogenic substances excreted into the environment. A total of 288 pigs were used in the experiment. The study was conducted using on 288 pigs. The experiment was begun when the pigs were 28 days old. The piglets in the control group (C) were fed a standard compound feed. Piglets in groups FRA (8% fermented rapeseed meal + pro- and prebiotic additives, organic acids, and ZnO) and FR (8% fermented rapeseed meal) received a diet containing 8% FRSMb in place of some of the soybean meal in the standard feed. Additives, pro- and prebiotic additives, organic acids, and ZnO were removed from the diet for the piglets in group FR. Rapeseed meal was fermented using Bacillus subtilis strain 87Y. The experiment was carried out for a period of 60 days. Gain:Feed (G:F) between 28 and 88 days was lowest in group FR. Coefficients of apparent total tract digestibility (CATTD) and coefficients of apparent ileal digestibility (CAID) of crude protein (CP), crude fat, and crude fibre were higher in group FRA than in group C (P < 0.05). Coefficients of apparent total tract digestibility and CAID of Cu, Zn and Fe were increased (P < 0.05) in group FR relative to groups FRA and C. Absorption and retention of P and retention as a percentage of absorption were higher in the groups receiving 8% FRSMb than in group C (P = 0.001; P = 0.008 and P = 0.007, respectively). Most indicators of Ca balance were increased (P < 0.05) in the pigs in groups FRA and FR in comparison to group C. The level of ammonia released in the faeces of the piglets was lower in group FR than in the control group (23.28% reduction). The amount of Cu excreted in the faeces was higher in group C (P = 0.009), but the amount excreted in the urine was higher in group FRA (P < 0.001). The results of the research suggest that the inclusion of 8% FRSMb in diets for piglets has a beneficial effect by improving the digestibility of protein and minerals and thus reducing their excretion into the environment.