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

Scientific experiments on determination of the optimal doses kizelgur for import substitution of shells in poultry diets was realized in the conditions of the Republic of Belarusby an example of 4 groups of laying hens of Khajseks korichnevyj cross. Hens of the first (controlled) group were given full ration applied at the tested poultry farm which included 5% of shells. Hens of the other three experimental groups were given complete feedstuffs with inclusion of mineral feed kizelgur: hens of the second group – in dose 2% out of dry matter mass; third group - 3%; for the fourth group - 4%. The research results showed that application of mineral feed additive kizelgur increased hen productivity in experimental groups on 2,8%; 5,9%; 7,2%, respectively. In the experimental groups there was an increasing of egg yields on 2,8%; 5,9%; 7,2%, respectively. The best indexes of poultry livability were stated in the third group (on 5,5% higher than in control). The similar tendency was stated in course of analysis of egg weight, shell thickness and calcium content of shell. Kizelgur application led to increasing of egg mass in tested groups: on 0,46% (2 group), 1,6% (3 group) and 2,4 % (4 group). At the age of 340 days shell thickness in experimental groups was on higher 3,3% (2 group), 0,7% (3 group) and 8,7 % (4 group) than in control. The analyzed additive increased the natural resistance of hens that was proved by indexes of bacterial growth-inhibitory activity of blood serum and lysozyme activity. There noted tendency of total protein increasing. Studying of immunological indexes showed that they were the most evident in the fourth experimental group

Investigation of influence of complex probiotic preparation Laktimet obtained by means of cultivation of bifidus bacteria and lactic acid bacillus on morphological indexes of pancreatic gland of laying hens was realized in the conditions of the Republic of Belarus. Two groups of laying hens of 121-130 days old were used in the experiment. The experimental hens were given probiotic Laktimet with water in dose of 1 ml/head every day in 4 cycles during 7 days and with 7 days intervals. Total condition, dynamics of body weight, and egg production were estimated. Research results showed that body weight of experimental hens increased on 6,4 % on the 10-th day; on 12,1% - on the 24-th day; on 6% - on the 40-th day; and 7,5% - on the 50-th day of experiment. Pancreas weight of experimental hens increased on 4-9%. Acinus size increased on 11%. Morphological indexes in exocrine pancreatic cells showed that altitude of basal pole increased on 3-7%. Application of probiotic Laktimet rendered positive influence on laying hens that was evident in increasing of their productivity (there was an increasing of live weight on 4-8%, and egg-laying capacity – on 18-33%). The positive dynamics of the majority of morphofunctional indexes of exocrinous and endocrine parts of pancreatic gland proved its significant role in maintenance of general state of laying hens and metabolic processes