In the conditions of the Republic of Belarus there was studied the influence of various doses of dolomite on productivity, egg quality and a mineral metabolism of laying hens. The research was realized by an example of laying hens of Highsex Brown. The experimental hens at the age of 250 days old were divided into 4 groups on 60 heads in each by means of analog method. Laying hens of the first (control) group were fed with a basic diet including 5% of a soya cake (cockle-shell), and hens of the second, third and fourth (experimental) groups instead of a soya cake were fed with a mixed fodder with addition of a mineral additive of dolomite. Hens of the second group were fed with the additive at a rate of 2%, the third group - 3%, and the fourth group - at a rate of 5% of weight of dry matter of forage. During the experiments there were maintained optimum parameters of microclimate, recommended temperature and light regimes and a sufficient ultra-violet irradiation. As a result of the realized research it was established, that use of the mineral dolomite additive in feeding of laying hens proved to be possible as a substitute of an expensive import cockleshell. Use of various doses of dolomite promoted improvement of mineral metabolism, increasing of productivity and improvement of egg quality of laying hens.

Possibility of increasing of natural resistance of young livestock animals and productivity of piglets after application of experimental feed additive including dolomite powder was realized in the conditions of the Republic of Belarus. In course of study there were analyzed housing conditions of piglets; the hygienic examination of feeding rations; influence of dolomitic meal on piglet resistance and productivity. Piglets of the first (control) group were fed with standard total ration. Animals of the second and the third experimental groups were given dolomite powder in ratio of 1% and 2% of combined feed mass. Chemical content of dolomite powder, hematological indexes, disease incidence and piglet productivity were analyzed. The research results showed that in feeding rations of piglets in the analyzed swine breeding complex there was stated the deficit of calcium (14%), phosphorous (26%), magnesium (15%), cuprum (9%), zinc (27%) and manganese (27%). Research results showed that application of dolomite meal is efficient for the prophylaxis of mineral deficiency, and made it possible to increase the level natural resistance: serum bactericidal activity - on 16,4% and hemoglobin - on 19%. The optimal dolomite dose of dolomite was 2% and it promoted the lowering of disease incidence, increasing of viability and average daily weight gain