In the conditions of the Republic of Belarus there was analyzed the influence of inclusion into broiler chickens diets of probiotoc preparation Bifidoflorin zhidkij (liquid) and prediotic veterinary drug Biofon AIL on the natural resistance, hematopoiesis, growth, metabolic function, development and viability of broiler chickens. In course of the study there was analyzed the dynamics of total haemoglobin, total protein of blood serum, albumins and globulins of broiler chickens which were fed with veterinary drugs probiotoc Bifidoflorin zhidkij and prediotic Biofon AIL. Indexes of chicken viability and life weight gain were marked. Research results showed that application of the presented veterinary preparations rendered the growth promoting action, lowering of disease incidence, increasing of chicken viability, increasing of live weight gain and stimulation of metabolic processes in the most intense period of poultry growing. All these factors were expressed in highest degree after the combined application of the probiotic and prebiotic veterinary drugs.

Evaluation of safety and efficiency of application of immunostimulative drug Izambenum (C14H15IN2O) for stimulation of natural resistance (autarcesis) and immunologic responsiveness of chickens of laying breeds was realized in the conditions of the Republic of Belarus. Clinical and experimental investigation of Izambenum influence on poultry for the increasing of their resistance, activation of immunological response to vaccination against Newcastle disease, stimulation of their growth and development was realized. Research results showed that Izambenum influenced on level of morphological indexes of chicken blood: number of erythrocytes increased on 24%, hemoglobin - on 17%. Total protein in blood serum increased in all test period and number of lymphocytes increased and differential was 90-100%. Izambenum increased strains of post vaccination immunity to Newcastle disease. Bacterial growth-inhibitory activity decreased on the 27the day of life and increased at the same positions on the 34-41 days. Phagocyte activity of pseudoeosinophils increased in all test groups. Research results showed that Izambenum rendered growth and immunity stimulation action and increased their viability. Its immunostimulative action was conditioned by strengthening of cellular and to lower extent humoral immunity factors. Application of the preparation in period of Newcastle disease vaccination promoted the formation of long-lived immunity

Investigation of influence of probiotic Dialact and immunostimulant Alveozan on digesting of nutritive substances by broiler chickens of Kobb-500 cross, as well as control over their individual development were realized in the conditions of the Republic of Belarus. The first (control) group of chicken was given standard well-balanced ration. Chickens of the second group were administrated immunostimulant Alveozan in dose of 10 mkg/kg of live weight with drinking water once a day in course of 5 days, with 10 days interval till the end of the growing period. Chickens of the third group were administrated preparation Dialact in dose of 0,1-0,2 ml with drinking water once a day in course of 3 days, with 14 days interval till the end of growing period. Chickens of the fourth group were given Alveozan in dose of 10 microgram/kg of live weight once a day in course of 5 days with 10 days interval, and Dialact in dose 0,1-0,2 ml once a day in course of 3 days, with 6 and 14 days interval. Research results showed that complex application of probiotic Dialact and immunostimulant Alveozan increased the viability of chickens on 100%, average live weight - on 5,1%, average daily weight gain - on 5,1%. Administration of Dialact and Alveozan, both separately and in complex, increased the digestibility of nutritive substances of mixed fodders: application of nitrogen increased on 1,93-6,38%, application of calcium decreased on 10,41-12,54%, phosphorus use increased on 2,38%

Data on studying of efficiency of application of immunobiological preparations on efficiency and other clinical and biochemical indicators for chickens-broilers are cited. It is established, that their application to chickens-broilers promotes increase of biological value of fowl as foodstuff and is economically expedient. Application of a preparation the Biococktail-NK in an optimum dose 0,1 - 0,2 ml/goal (10,0-20,0 million microbic bodies) has allowed to increase intensity of growth of chickens-broilers by 3,5%, to lower forage expenses for production of a gain of body weight of 1 kg on 4,95%, to raise safety of young growth of birds on 3,4 % and to lower a case of birds to 1,6% (technological norm of 5%). The carried out calculations have shown, that introduction of the Biococktail-NK in a ration of broilers is economically justified, as safety of young growth in 4th trial group has raised on 3,4%, in the third - on 2,5%, in the second - on 1,3%. On the basis of the spent research fowl of the delivered samples in which ration it was entered the probiotic Biococktail-NK from calculation 0,1 - 0,2 ml/goal (10,0-20,0 million microbic bodies) since daily age within the first 5 days into 4 cycles with an interval of 7 days till the end of the cultivation period is established, that on organoleptic, physical and chemical, bacteriological indicators, and also biological value and harmlessness does not concede to meat of control group and is good-quality. In the literature there are data about influence of biologically active substances on growth and development of bird. Despite it, about influence of probiotical and immunostimulatory preparations as separately, and in a complex with probiotics, on an organism of chickens-broilers it is not enough data that induces carrying out of scientific research in the given direction. Simultaneous use of probiotics on the basis of an intestinal stick in rations of chickens-broilers is the perspective directions. Proceeding from it, working out of new effective ways of increase of chickens-broilers efficiency with a view of reception of ecologically pure and safe products of poultry farming is actual for poultry-farming economy of Belarus.

Application of protein, vitamin and mineral supplement in diets of 1-3 months old calves in rate of 5% per weight instead of a part of sunflower cake, containing rape, peas, lupin and vitamid on a basis of halites, phosphite, phosphate, sapropel and a mineral-vitamin preparation in structure of grain forage against winter rations on the basis of rich in herbs hay (5%), milk (68%), mixed fodder (20%), whole grain (7%), and also summer rations with grass and legume mixture (7%), hay (1%), milk (65%), mixed fodder (20%), integral grain (7%) makes it possible to receive daily average weight gain of calves at level 833-867 grams at expenses of forages for 1 centner of weight gain on 3,3-3,4 сentner of forage units. Introduction into rations of the protein, vitamin and mineral supplement on the basis of local protein and mineral raw materials in number of 10% per weight in structure of mixed fodder for calves at the age of 3-6 months old against the background of winter diets with haylage (28%), mixed fodder (64%), molasses (8%), as well as summer diets with grass and legume mixture (30%), mixed fodders (66%), molasses (4%) makes it possible to receive daily average weight gains of calves on 944-967grams at expenses of forages of 4,0-4,1 сentner of forage units. Feeding of 1-6 months old calves with mixed fodders with inclusion of 5-10% of protein, vitamin and mineral supplement per weight with grain high-protein crops against the background of winter and summer diets with a ratio of the deconjugate protein to the non deconjugate one - 65:35 (in control group - 71:29) instead of sunflower cake makes it possible to receive the daily average weight gain at the level of 900-927 grams at expenses of forages 3,7-3,8 сentner per forage unit. Cost of presented mixed fodders decreases on 14%, and the cost price per 1 centner gain - on 7-8%

Comparative evaluation of the influence of cell-free probiotic preparation Laktimet and cellular probiotic Bifilak on productivity, livability, nonspecific response of suckling piglets in the early extrauterine life was realized in the conditions of the Republic of Belarus.Application of both probiotics increased the productivity of suckling pigs, stimulated the processes of metabolism and natural protection of organism in the early postnatal period in the conditions of specialized pig breeding complexes. Research results showed, that application of brand new cell-free probiotic Laktimet exercised higher influence on suckling pigs. Application of Laktimet made it possibler to increase piglets body weight gain on 7,8%; piglet livability - on 6,7%; and application cellular probiotic preparation Bifilak - on 5,4% and 3,3%, respectively. The same tendency was noted during the analysis of indexes of cellular factors of organism protection. Bactericidal activity of blood serum of experimental animals changed both in connection with age, and under influence of probiotic preparations. During all studied periods the bactericidal activity of blood serum was authentically (P less than 0,05) above in experimental groups in comparison with a control group. At 20-days old piglets there was stated the strengthening of bactericidal activity of blood serum. Throughout all period of experiment the superiority of trial animals over control on indicators of lysozyme activity of blood serum was observed

Analysis of the optimal scheme of doses and rates of combined administration of probiotic Dialakt and immunostimulant Alveozan was realized in the conditions of the Republic of Belarus by the example of 1500 broiler chickens of cross Kobb- 500. Chickens of the first (controlled) group were given only total ration, balanced with the main nutrients. For the chickens of the second group were administrated with immunostimulant Alveozan with water starting from one day old age, every day in dose of 10 mkg/kg of body weight once a day in course of 5 days successively and with 7 days interval till the end of growing period; and probiotic Dialakt was administrated with water in dose of 0,1-0,2 ml/head (10,0-20,0 mln microbial bodies) starting from one day old age, once a day in course of 5 days successively and with 6 and 14 days intervals till the end of growing period. Chickens of the third group were administrated Alveozan in dose of 10 mkg/kg of body weight with drinking water once a day in course of 5 days with 10 days interval till the end of growing period; and Dialakt in dose of 0,1-0,2 ml/head with drinking water starting from one day old age, every day in course of 5 days with 6 and 14 days interval till the end of growing period. The research results showed the following optimal regime of complex application of the analyzed preparations: immunostimulant Dialakt - in dose of 0,1-0,2 ml/head with drinking water starting from one day old age, once a day in course of 3 days successively with 6 and 14 days intervals till the end of growing period; and immunostimulant Alveozan - in doze of 10 mkg/kg of body weight with drinking water once a day in course of 5 days with 10 days interval till the end of growing period. Complex application of Dialakt and Alveozan promoted the increasing of organometric indexes, specific volume and size of thymus in 1,5-1,8 times (P less than 0,01), Fabritsiya bursa - in 2 times (P less than 0,01) and lien - on 11,1% (P less than 0,05)

Studying of efficiency of application of a natural biological control agent BioLAD obtained as a result of cultivation of Fusarium sambucinum fungus in feeding of broiler chickens was realized in the conditions of the Republic of Belarus. There were studied 100 broiler chickens of Ross-308 cross. Broiler chickens of the first (control) group were fed with standard diet with PK-5-1. Broiler chickens of the experimental groups starting from one day old age till the end of the growing period (41 days old) were fed with feed supplement BioLAD in different doses: 0,25 ml/head (second group), 0,5 ml/head (third group), 1 ml/head (fourth group). Research results showed that natural biological control agent BioLAD in dose of 0,5 ml/head made it possible to increase chicken live weight on 11,2 %, viability - on 4,2%. Feeding charges per 1 kg of live weight gain were1,89 kg (second group), 1,81 kg (third group), 1,90 kg (fourth group). It made it possible to decrease the combined feed charges on 6,4% (second group), on 10,4% (third group), and on 5,9% (fourth group). Application of biological control agent BioLAD had an effect on poultry growth activity, promoted high level of chickens viability, increased the indices of general and local protection, stimulated metabolic processes

In course of realized in the conditions of the Republic of Belarus evaluation of growing intensity and level of meat productivity depending on cattle sex there was conducted the scientific and economic experiment by an example of two groups of white-and-black bull-calves and heifer calves. In the first growing period the animals of experimental groups were fed with milk substitute. At the stage of completion of growing and fattening the bulls and heifers of experimental groups obtained ration containing haylage, plus 2 kg of flattened grains and 2 kg mixed fodders. Results of linear and weight indexes analysis showed that in changes of exterior of bulls and heifers of black-and-white breed there was noted a certain regularities in their growth and development. The most intensive growth and development of analyzed young cattle was stated at age from 6 till 12 months. At the same time, bulls exceeded heifers according to the main exterior indexes. According to the visual evaluation of bulls and heifers there were determined the differences in constitutional type