Investigation of morphological changes in bone marrow of young hens in the conditions of application of associated virus vaccines and sodium thiosulphate immunostimulant was realized in the Republic of Belarus. The associated virus vaccine was applied against infectious bursal disease, infectious bronchitis, infectious laryngotracheitis, and Newcastle disease. Research results showed that under the influence of inactivated vaccine against mentioned above diseases there was noted the increasing of quantity of granulocytic cells, there was stated an active hyperplasia of pseudoeosinophil cells. Immunization of young hens with the presented vaccine developed in the Institute of Experimental Veterinary Medicine of the National Academy of Sciences of Belarus promoted a short-term increasing of leucoerythroblastic index. Application of an alternative vaccine developed by Scientific and Production Enterprise Avivak did not render substantial influence on the morphology of bone marrow of chickens. Sodium thiosulphate applied in combination with associated vaccines (in 7% concentration in vaccine) caused the hyperplasia of lymphoid and thrombocyte cells, strengthened the proliferation and maturity of granular leukocytes

Scientific and production examination of feed additive Semerik-Vita containing iodine and selenium was realized in the conditions of the Republic of Belarus by studying of its influence on production and economic indexes of laying hens and their products, as well as by studying of its influence on clinical state and biochemical blood indexes of poultry. Research results showed that application of feed additive Semerik-Vita made it possible to increase of egg producing ability intensity on 1,8 %, egg yield - on 2,4 % in the conditions of lowering of feeding expenses on 1,4 %. Application of the analyzed feed additive made it possible to obtain a new kind of eggs fortified with iodine, selenium, beta-carotene and vitamins (A, E, C, PP, B1, B2, pantothenic acid and folic acid). In eggs of poultry of experimental group the content of selenium increased in 2,1 times, iodone - in 1,5 times, vitamin E – in 3,9 times, beta-carotene – in 1,4 times, vitamin A – in 1,3 times, pantothenic acid – in 1,2 times, vitamin C – in 1,17 times, vitamin PP – in 1,4 times, vitamin B1 – in 1,5 times, vitamin V2 – in 1,4 times, folic acid - in 1,5 times in comparison with eggs of laying hens from the control group. Research results proved that application of Semerik-Vita did not render negative effect on the clinical indexes of laying hens. It made it possible to lower the content of urea acid in 1,7 times, as well as to increase the content of triglycerides in 2 times, cholesterol - in 2,4 times, magnesium - in 1,28 times

Application zoned bare-grained oats grades in a diet of chickens and hens-layers of egg breeds makes positive impact on efficiency of a bird, forage conversion, reduces expenses of forages for manufacture of eggs that allows to receive additional profit. The maximum norm – 40 % bare-grained oats in mixed fodders of hens is defined

Solution for ecological purity of livestock products that is presented in our research is monitoring of the polluted by heavy metals and radionuclide areas exploration on the aspect of antioxidants content in soils, forages, livestock products and determination of ratio of toxic matters transition into milk