Common carp (Cyprinus carpio) is one of the most widely cultured fish species in the world. It is predominantly cultivated in the Balkans in the semi-intensive system that is based on the utilization of natural food from the fish pond and supplemental feed (cereals, pelleted and extruded feed). Currently, an intensified type of semi-intensive production is starting to be more present in Serbia, where cereals, as the most common supplemental feed, are replaced by concentrated feed that fill in the lack of proteins from carps’ natural food in periods of its decreased production. The nutritional requirements for growth, reproduction and normal physiological functions of fish are similar to other animals,but generally fish need more proteins in their diet. Due to this, the efficiency in the use and utilization of proteins is more significant for fish than for other animals. The selection of supplemental feed in semi-intensive system of fish culture depends on the natural potential of the fish pond, culturing period, fish category, price and quality of feed.