The aim of the study was to assess the effect of the inclusion of dried fermented soybean and/or rapeseed meal in piglet feed on immune parameters, blood lipid parameters, and mineral content in the blood and metacarpal bones. The study was conducted on 150 28-day-old piglets divided into 5 groups. Piglets in the control group (C) received a standard diet with soybean meal. Animals in group FR (group receiving a diet with 8% FRSM) received a diet in which a portion of the soybean meal was replaced with 8% dried fermented rapeseed meal (FRSM). Animals in group FR/FS received a diet in which a portion of the soybean meal was replaced with 6% FRSM and 2% fermented dried soybean meal (FSBM). The piglets in group FS/FR received a diet with 6% FSBM and 2% FRSM. Group FS received a diet in which a portion of the soybean meal was replaced with an 8% share of FSBM. The inclusion of 8% or 6% fermented rapeseed meal (group FR or FR/FS) in the diet of piglets had a beneficial effect on their immune status, as evidenced by the increase in plasma levels of IgG and IgA and the decrease in IL-6 relative to the control group. It also significantly increased the concentrations of minerals, i.e. P, Ca and Zn, in the blood plasma and metacarpal bones of piglets and improved the availability of iron, a key bioelement involved in haemoglobin. The use of 8% or 6% fermented soybean meal in the diet (groups FS and FS/FR) of piglets had a positive effect on blood lipid parameters, reducing CHOL and LDL-cholesterol in the plasma. In conclusion, the fermentation process enables better utilization of rapeseed or soybean meal by pigs. Dried fermented rapeseed meal could partially replace protein components from GMO (genetically modified ogranism) crops (soybean meal) used in diets for pigs.