Mineral elements play very important role in the adequate animal feeding, including suckling piglets, due to their active part in metabolism, providing normal functioning of all inner organs, muscles and nervous system.

Absence or lack of some mineral elements, and violation of their correlation results in the decline of efficiency use of ration nutrients and, as a result, in the productivity decline.

The adequate feeding of suckling piglets in most economies of Ukraine is provided by the before started mixed fodders of the imported production that results in the increase of pork prime cost. In addition, the traditional sources of microelements in these mixed fodders are mineral salts as sulfate and chloride compounds which bioavailability amounts 12-35% that results in contamination of environment by heavy metals, and the crystallized water that is contained in the molecules of sulfates in composition of premixes, destroys vitamins and other biologically active substances.

To reach high level of the productivity of animals on condition of maintenance of their health and obtain ecologically clean products is impossible without providing animals with biologically-active substances. In this connection in recent years much attention is paid to study the influence of different vitamin-mineral additions of organic origin on the productivity of animals.

The rate of microelements uptake increases with the use of forage additions with the organic origin microelements. The representatives of such forage additions are mixed ligand complexes of microelements (chelates), added to the composition of mixed fodders. Adding such mineral additions to the mixed fodders for pigs gives perceptible economic effect that is seen in productivity increase and improvement of feed nutrients uptake, however their influence on the growth of animals and slaughter indices are studied not enough.

While adding to mixed fodder the metal organic addition of copper the methods of weight dosage and multistage mixing were used. During investigation there were studied growth, absolute and average daily gain of pigs live weight, and their slaughter indices were calculated.

One of the leading and at the same time integrating indices that characterise the state of metabolic processes and their anabolic orientation for introduction of copper mixed ligand complex is live weight index.

For the estimation of animals on precocity and live weight it is necessary to know how corresponding indices change during different periods of development. In zootechnics one of such indices, that characterizes economic and physiology precocity is absolute live weight increase. 

During 3-15 days period the absolute live weight increase of tested groups piglets differed little from the control groups.

During basic experiment period of 3 to 28 days age, the absolute live weight increase of animal of all tested groups exceeded the control index.

So, in the piglets of Large White breed by absolute increase the fifth tested group showed the best at the doses of 2,72 gr/t copper mixed ligand complex  of the mixed fodder; in the piglets of Landras breed is the fourth tested group – 5,45 gs/t of mixed fodder; in three- and four breed hybrids is the third tested group containing 10,9 g/t copper mixed ligand complex of mixed fodder. Thus, advantage of suckling piglets on this index as compared with the analogues of control groups presented, accordingly 12,7% ( р<0,001); 10,5% (р<0,01); 8,4% ( р<0,01) and 6,5% (р<0,05).

By the absolute increase index it is impossible to compare the intensity rate of piglets growth as it is impossible to set interconnection between the animal weight and growth intensity. Therefore animal growth rate is determined by a relative increase.

At the age of 3-15 days, piglets of tested groups in the first and the second scientific-economic experiments prevailed the control analogues by the growth intensity rate that depended on the form of copper feed and piglets breeds. So, the greatest index of live weight relative increase was determined in piglets of the 5-th, the 4-th, and the 3-d tested groups, and this advantage presented in relation to control, accordingly, 16,5% (р<0,01); 14,9% (р<0,05); 12,0 and 11,7 %.

In the next age period (15-28 days) advantage on the relative increase of live weight was saved in the first scientific-economic experiment in the piglets of the 5-th and the 4-th tested groups as compared with the animals of control group and presented accordingly, 1,5 and 5,0%  and in the second experiment – in the animals of the third tested groups – 2,0 and 3,1%.

The greatest index of relative increase of live weight during all investigation period (3-28 days) was determined in the piglets from the 5-th tested group of Large White breed, the 4-th group Landras breed and in the 3-d group of piglets of three- and four breed hybrids with dose of copper mixed ligand complex at 2,72 g/t; 5,45 and 10,9 g/t of mixed fodder. These indices exceeded control, accordingly by 32,8%; 34,7; 29,5 and 25,1% that specifies to more intensive growth of piglets from the tested groups.

Key words: piglets diets, performance, digestibility, mixed fodder.