The aim of the study was to perform feeding experiments on growing pigs in order to assess the impact of macroalga Enteromorpha sp. enriched with Zn(II) and Cu(II) ions via the biosorption process on the mineral composition of blood, meat, liver, feces and urine. In the control group, microelements were supplemented as inorganic salts, whereas in the experimental groups they were replaced by enriched macroalga. After 3 months of the feeding experiment, it was found that the meat was biofortified with Cr, Mn, Fe, Cu and Zn. The average content of Zn in the blood from the pigs fed with algae was higher by 9.5%, compared to that in the blood from pigs in the control group. The liver of growing pigs from the experimental group contained 16% less Cu and 18% less Zn than the liver in the control group. Growing pigs fed with macroalgae excreted in feces 27% more Zn than growing pigs in the control group, but 3.5 times less Cu. It could be concluded that the bioavailability of microelements to pigs from algae was higher than from the inorganic salts. Baltic macroalgae enriched with microelement ions could be potentially used as a biological feed additive.