As a result of the realized in the conditions of the Republic of Belarus research on revealing the influence of polymorphism character and the influence of presence of various allelomorphic variants of IGF-2 gene in breeding boars genotype on fattening and carcass traits of stores of Belarusian large white and Belarusian meat breeds it was established: 1. frequency of occurrence of desired QQ genotype among boars of the Belarusian meat breed was rather low and has made 10%. Among boars of the Belarus large white breed the given genotype has not been revealed. Heterozygotic genotype Qq had a rather wide range - from 26,6% at boars of the Belarusian meat breed to 43,2% at boars of the Belarusian large white breed; 2. fattening boars of both studied breeds which had been received from the boars bearing in their genome Qq genotypes of IGF-2gene showed the tendency for predominance in fattening and carcass traits over their herdmates which had been received from the boars bearing in their genome qq genotypes; 3. The posterity of boars of the Belarusian meat breed bearing in their genome the homozygous QQ genotype, authentically surpassed in fattening and carcass traits their analogues which had been obtained from fathers with a genotype qq. The following traits were higher: age of achievement of body weight; daily average weight gain in case of fattening; feed expenses per unit of live weight gain; slaughter yield; weight of a back third of half carcass. Research results showed, that IGF2gene (a gene of the insulin-like growth factor) could be a perspective candidate gene which makes it possible to predict the growing capacity and carcass trait of pigs of Belarusian breeds. Taking into consideration the influence undesired q allele, for the increasing of fattening and carcass traits of pigs it was possible to recommend the realization of estimation of replacement boar pigs using the data analysis of their genotype of IGF2 gene, as additional criterion of their selection

For the first time in the Republic of Belarus there were developed the effective methods of marker-dependent selections directed towards increasing the performance traits and preventive measures of pig diseases of the Belarusian Large White breeds. Application of the presented techniques in practice made it possible to increase the multiple fetation of sows on 0,5-1,5 piglets, increase livability of stores on 1,1-5,7%, increase the average daily weight gain on 17g, lower feed expenses on 0,04 FU. In course of the realized studies there was studied the polymorphism of Ryr-1, ESR, E.Coli (ECR F 18) FUT 1 and IGF-2 genes, there was developed the efficient methods of marker-dependent selection. Research results showed that application of methods of molecular gene diagnostics proved to be economically feasible. In the conditions of rather low expenses for testing of boars and sows there was stated the considerable increases in economic efficiency of pork production. Creation of reserve populations with a desired genotype breed will make it possible to accelerate the breed-forming process

The necessity of creation of the optimal conditions for production of high-quality dairy products was conditional upon the fact that milk is very unstable by its chemical and physical indicators biological liquid. There is no point in improving milk quality after the realized production. Results of the realized in the conditions of the Republic of Belarus evaluation of milk according to the sanitary and hygienic indices for the further improvement of its quality were presented. According to the data on milk purchasing it noted that in Belarus there was stated a noticeable reduction of milk quality in accordance with its grade of quality. Throughout the last years the relative density of realization of the premium quality milk was less than 50% (46,5% - in 2005, 48% - in 2006), and at the same time, the volume of sales of the second second-rate quality milk reduced on 7,6%, and volume of off-grade milk - on 0,7%. Milk quality at the studied in course of investigation dairy farms in the majority of cases was conditional upon such indicators as base-titratable acidity, bacterial number and quantity of somatic cells in milk. Titrate acidity indices in over than 36% of milk does not correspond in to standards of the Republic of Belarus. Evaluation of bacterial number in the produced milk showed that its main production volume (65,2%) corresponded to the first and second grades and 6,7% were off-grade quality. Somatic cells content in the studied milk samples in 27% corresponded to the extra fine grade, and only about 2% of the analysed milk samples corresponded to off-grade milk

The growth and development of replacement gilts of different precocity and age depending on the terms of transition from herd-producer to the market area of a complex was studied in the conditions of the Republic of Belarus. Animal transfer into new housing conditions affected the early maturing and super early maturing breed pigs of experimental groups. It was determined that moving of replacement pigs into the market area of the complex at the age of 115 days made it possible to obtain higher indices of swine productivity. Fertilization rate of sows of the first experimental group after the first insemination made up 77,6%, that was higher on 6,2% and 9,5% in comparison with the control and the second experimental groups, respectively. The advantage of the first and second experimental groups over the control one was stated in a higher multiple fetation on 0,4 heads and heightened heavy litter indices on 0,1 kg; the quantity of weanling was higher on 0,6 and 0,5 heads, on litter weight at weaning was higher on 7,1 and 3,8 kg, respectively

Research and production experiment on studying the efficiency of calve growing depending on the methods of their husbandry at the prophylactic and lactic periods was realized in the conditions of the Republic of Belarus. It was established, that calves which were kept in course of the analyzed periods in group cages of a calf-house at the age of 180 days had live weight on 9 kg (or on 5,4%) higher than cattle kept in course of the prophylactic period in individual cages of a prophylactorium calf house, and at the same time their live weight was on 3 kg higher (or on 1,7%) rearers kept in the same period in group cages on the open air conditions. The average daily live weight gain of cattle was also higher on 7,2 and 1,6%, respectively. However, in the conditions of the group husbandry of growing stock in the calf houses there was stated that the analyzed animals were more often ill, so it could be concluded that the presented animal husbandry method could be used only in favorable epizootic conditions in animal husbandry farms. In the conditions of an open air husbandry the ways of infection diseases incidence was substantially lower, and calves showed high development indices in case of complete feed diets application

The increasing number of diseases with urogenital chlamydiosis became a serious problem for the modern veterinary science. The importance of urogenital clamidiosis in the infectious pathology of animals was presented by the direct multifocal affect of urogenital system and after-effects of a disease influencing the reproductive function, as well as the potential hazard of its transformation into a source of chlamydia infections of other localization. In the conditions of the Republic of Belarus the chlamydial endometritis of cattle in the majority of cases was associated with Staphylococcus aureus in 25,7% of cows. Chlamydial endometritis of cows was usually preceded by: embryotocia (9,9%), pathological calving (4,4%), retention of placenta (14,8%), subinvolution of uterus (27,1%). The biochemical tests in trial group showed the 23% decrease of carotin on twofold decrease vitamin A. In course of the immunologic studies it was established, that dilution of A class immunoglobulins was on 31% higher in animals of a trial group in comparison with the control group. The level of IgG immunoglobulin G and immunoglobulin M slightly differed between groups

Research of the selection efficiency of boars of Belarusian meaty and Large White breeds for reproduction and productivity indices was realized in the selection and breeding centre Zadneprovski in the Republic of Belarus. The influence of 25-percentage level of boar selection for sperm production with the dominancy of relative average values of an initial population on statistically significant difference within the limits P less than 0,05-0,001 was proved. Application of an evaluation criterion of animal breeding abilities by the degree of frequency of departures from a population level with a value which reflects the intensity of selection in shares of an average quadratic deviation made it possible to raise the breeding value of boar of both genotypes in accordance with the productive qualities of descendants in comparison with average sizes of populations of two breeds on statistically authentic difference at P less than 0,05-0,001. Decreasing in the studied indicators of efficiency of offsprings concerning initial fatherly forms could be explained by a stronger influence of environment conditions rather than genetic predisposition of genotypes to the given traits

Studying of peculiar features of external conformation of replacement gilts used for the further closing stage of commercial cross breeding as well as for the further productivity of first litter gilts was realized in the conditions of a swine breeding stock-rearing farm of the Republic of Belarus. In the modern zootechnic classification it is reasonable to divide pigs into 3 constitutional types of their external appearance: leptosome, transitional, and oerisome. In the conditions of industrial engineering the replacement pigs and sows of transitive type in comparison with individuals oerisome and leptosome types were characterized by higher productivity: early terms of insemination (on 3,2 and 3,3 days, respectively); livability of stores at weaning stage (on 5,8 and 5%, respectively), higher litter size at weaning stage (on 7,1 and 6,3 kg), higher input share into the basic pig stock (on 4 and 6%), and a yield of a gross of body weight gain of litter at fattening with a view to farrow (on 8 and 10%). Piglets of the transitive type sows were characterized by the steadier parameters of metabolism in comparison with stores of leptosome type sows (there were less frequently encountered the disturbances of infringements of trace mineral and calcium and phosphoric metabolism). On the basis of the realized research there were developed the technical specifications of the Republic of Belarus 600039106.001-2004 Replacement gilts; Manual on appraisal of quality of pigs for repair of herd of a pig-breeding complex; the Technological instruction on herd repair of a pig-breeding complex; production schedules Normalization of reproductive function of replacement pigs in the conditions of a complex

In the research the genetic structure of populations of bulls Vitebsk of cattle breeding state farm and cows of Belarusian Black-and-White breed of Joint-Stock Company Olgovskij of Vitebsk region (Republic of Belarus) on a locus of a gene of kappa-casein was analyzed. As a result of genotyping a gene of kappa-casein by DNA-diagnostics method there were revealed three genotypes CSN3**AA, CSN3**AB, CSN3**BB. Frequency of occurrence of homozygous genotype CSN3**AA at cows has made 69,5%, at bulls of Vitebsk cattle breeding state farm - 78,3%; heterozygotic genotype CSN3**AB - 26,3% and 20,5%; homozygous genotype CSN3**BB - 4,2% and 1,2%, respectively. Frequency of CSN3**A allele in population of cows and bulls has made 0,83 and 0,88; CSN3**B - 0,17 and 0,11%, respectively. The presence of authentic influence of polymorphic variants of a gene of kappa-casein on level of milk yield and fat and protein content in cow milk was stated. The highest milk productivity in course of 305 days of lactation was observed at cows with homozygous genotype CSN3**BB (5984 kg), that was on 890 kg higher than in animals with genotype CSN3**AB (5094 kg), and on 1406 kg higher (Р less than 0,05), than at animals with CSN3**AA genotype (4578 kg). Cows with B kappa-casein allele in genome were characterized by higher fat content in milk (CSN3**AB - 3,61%, CSN3**BB - 3,72%) than animals with a CSN3**AA genotype - 3,60%. Cows with genotype CSN3**BB had higher level of protein in milk (3,28%) in comparison with the animals with CSN3**AA genotype (3,18%). In animals with CSN3**AB genotype the mentioned above index 3,19%. Research results showed that genetic variants of the gene of kappa-casein are important for selection practice as they could be used as breeding-genetic markers which could raise milk yields and protein content in milk

Research of the influence of biologically active preparations of natural origin on zoological indices and quality of animal products was studied by the example of their application in broiler chicken diets in the conditions of the Republic of Belarus. On the basis of realized research it was established, that application of biologically active substances immunoamplifier Alveozan, probiotic Dialakt, probiotic Bifidoflorin liquid, prebiotic Biofon and prebiotic Biofon AIL (produced in the Republic of Belarus) did not render negative effect on quality of animal products (all studied meat samples had high quality). The received results testify to necessity of complex application of the above-stated preparations. Application of biologically active preparations made it possible to increase livability of growing birds on 100%, average live weight increase from 1,9 up to 5,1%, daily average weight gain - from 1,9 up to 5,1%, improvement of feed conversion ratio - from 18,3 up to 21%. All studied biologically active preparations made it possible to restore the physiological environment in poultry intestines, normal flora, to suppress the growth of pathogenic microorganisms. The above mentioned preparations could be applied both with preventive, and with the medical purposes