Balance experiment on a diet nutrients digestibility study was conducted within the scientific-economic experiment. For this experiment, 3 young boars – brothers by father - were picked from each group according to the analogue principle. They were placed separately, each in a specially equipped cage. The experiment lasted for 8 days and had two periods: preparatory (3 days) and accounting (5 days). The animals were fed with complete mixed fodder twice a day, when necessary the uneaten remains were taken away. During the accounting period of the exchange experiment the amount of secreted feces and urine was considered. Average samples of the collected feces were taken and placed into glass jars with ground stoppers and preserved by 10 % hydrochloric acid solution with 10 ml per 100 g of feces and 100 g of urine.

To determine the effect of Copper organic-mineral compound on mixed fodder nutrients digestibility we conducted physiological (balance) experiment on 15 piglets.

Different doses of Copper organic-mineral compound had different effect on nutrients digestibility in piglets diet. Thus, organic matter digestibility in Large White breed piglets, which consumed mixed fodder, that contained 50 and 100 % of the copper norm (experiment groups 2 and 3), was about the same level as the control one. The experiment groups 4 and 5 had higher digestibility,  respectively by 0,71 % and by 1,21 % but valid difference was observed only in the experimental group 5 (p<0,05).

A similar pattern is typical for the figures of crude protein digestibility. Thus, the crude protein digestibility coefficient in pigs of the experimental group 5 exceeded the control, respectively, by 1,02 (p<0,05).

Having explored the digestibility coefficients in pigs of Landrace breed, we found that the experimental group 2 animals dominated over the analogue counterparts of the control group for crude protein digestibility, respectively by 0,37, group 3 – by 0,45, group 4 – 0,94 (p<0,05) and group 5 – by 0,52 %.

Crude fat was also digested better in the piglets of experimental groups 2, 3, and 4. Animals of these groups dominated their counterparts in the control group for crude fat digestibility coefficient by 0,06; 0,02 and 0,14 %, respectively, while the pigs of the experimental group 5, showed decrease in fat digestibility by 0,05 % compared to the control group counterparts.

Under the reduction of Copper in quality mixed fodders in groups 3, 4 and 5 a clear tendency of nitrogen free extracts (NFE) digestibility coefficients increase is being observed. This figure exceeded in the animals of the above mentioned groups the control ones by 0,27; 0,43 and 0,32 % respectively.

By the results of the second physiological experiment it is established, that application of quality mixed fodder with copper chelate in the amount of 10,9 g/t contributed to the total increase in digestibility coefficients of the diet in the bodies of three- and fourbreed pig hybrids according to the control group animals: the organic matter by 0,26 – 0,30 %; crude protein by 0,62 – 1,31 %; crude fat by 0,58 – 1,69 %; nitrogen free extract substances by 0,17 – 0,47 %.

Thus, the presence of a stable trend of improvement of all the investigated parameters (compared to the control) demonstrates some positive effect from using lihandmix copper complex.

Therefore, using different doses of lihandmix copper complex contributed to increasing organic matter digestibility by 0,5 – 1,21 %, crude protein – by 0,37 – 1,02 %, crude fiber and NFE by 0,05 – 0 63 % and 0,09 – 0,6 % respectively in piglets of Large White and Landrace breeds.

The second scientific and economic experiment displayed some positive effect of using lihandmix copper complex and more compelling reliable data were obtained in animals of the third experimental groups under the application of copper chelate in the amount of 10,9 g per ton of mixed fodder by the absolute majority of indices.

Key words:  piglets, diets, productivity, digestibility.