It was studied chemistry including amino acid composition longest back muscle of young rabbits of different ages depending on the content of biologically active additives (BAA) for rabbits in complete feed. The necessary number of dietary supplements to provide cheap protein of young rabbits. For the experiment, 60 selected animals aged 45 days, of which the principle of analogues formed three groups: control and two experimental, on 20 goals each. Test young rabbits kept in bunk cellular batteries. Each cell size of 105 . 97 . 72 cm to 5 units (females and males separately). At the age of 60, 90 and 120 days scored 4 head of calves from each group (2 males and 2 females) and their subsequent dissection and weighting of the individual and determining the chemical, including amino acids, the longest part of the back muscles. Selection for slaughter animals with a live weight of which corresponded to the average for the group was carried out. Depending on the content of the fodder supplements in some way changes the total content of amino acids in the longest back muscle calves. At age 120 days, the highest content of essential amino acids in the longest back muscle was observed in animals of group 2 (2% BAA), in which it was 2.1–0.4% from the corresponding figure in animals other groups. In the longest muscle of rabbits that are grown on the fodder containing 2% of supplements contained less than 1.44% at BAA and 0.66% ash and 0.2% more calcium than those who did not receive this supplement. When used in feeding young rabbits of Full-feed supplements with containing 2%, increases the content of fat in the longest muscle in the back 0.63–0.81%, 0.54–3.95% at BAA.