In the conditions of the Republic of Belarus there was analyzed the efficiency of application of a probiotic lactic casein feed additive DKM which was developed in the Institute of Microbiology of the National Academy of Sciences of Belarus. The analyzed additive contained specially selected lactic-acid bacteria with a high bioartificial potential of metabolites. In course of the experiment there was studied the consumption of fodders (milk; oats; mixed fodders) by experimental calves; dynamics of live weight gain in the beginning and at the end of the experiment; average daily weight gain. Also, there were analyzed the background indexes of blood serum of calves, as well as the indexes of blood serum of calves in a month after application of DKM additive. Research results showed that application of the feed additive DKM promoted better palatability and use of fodders and rendered positive influence on animal productivity. Also, there was marked the normalization of metabolism that was proved y the laboratory tests of blood serum.

The influence of polymorphism of gene IGF-2 on feeding and meat qualities of pigs of Belarusian Large White breed was studied. It is established, that frequency of presumptive preferable allele Q gene IGF-2 reaches 0,75-0,98% at boars of meat breeds and 0,34% - at Belarusian Large White breed. The young boars of breed with genotype QQ authentically surpass the analogues with a genotype qq on development, and feeding young pigs – on meat-feeding to qualities. Gene IGF-2 it is possible to consider as genetic marker of growth rate of pigs of the Belarusian Large White breed

For soil – climatic conditions of a northeast part of the Republic of Belarus is recommended cultivating four-componential – fodder grass with two leguminous components (meadow clover + Lucerne sowing+ meadow timothy+ meadow fescue), productivity of which green weight has made 500 – 550 centers per hectare, gathering of crude fiber-19-21 centers per hectare. Inclusion of Lucerne sowing in clover-cereal fodder grass has provided a share of a leguminous component on average for four years no less than 75%

Balancing of mixed feeds for replacement gilts considering the metabolically energy level and essential available amino acids amount increases growth speed of animals at 9,6% (P less than 0,05) compared to mixed feeds prepared in correspondence with detailed norms of feeding; it also decreases terms of animals pedigree usage from 277 to 223 days

In the article showed results of the researches of the influence on productive longevity of cows of such factors, as a linear belonging, a genotype of the father, type of selection are stated. The lead researches have shown, that more longer duration of use characterized the animals belonging to line Siling Trajdzhun Rockit 252803 - 4,5 lactations. Among daughters of various bulls the greatest term of productive use daughters of the bulls the Silach 158 - 5,0 lactations differed. At the maximal deviation in efficiency of ancestors (6001-7000 kg of milk) longevity of their daughters was the greatest and has made 4,18 lactations. The greatest influence on duration of economic use of cows was rendered by specific features of bulls (32,2%) and a linear accessory -12,0%. While the selection variant practically does not influence longevity of animals - a share of influence of 3,7%

In the experiment with swine there was studied the influence of ultra-violet and various doses of narrow-band red radiation on efficiency and safety of animals. It has been established, that efficiency and safety of animal skilled groups in comparison with animals of control group has risen. Use of an ultra-violet and narrow-band red irradiation with frequency rate of inclusion of red light three times has a day allowed to raise average alive mass of young plants of pigs on 2,5 kg or on 9,1% (Р less than 0,01), a daily average gain - on 9,6%(Р less than 0,001) and safety of animals - on 10%

Determination of the optimal doses of selenium inclusion into premix structure for breeding boars for the maintenance of their higher producing capacity was realized in the conditions of the Republic of Belarus. Selenium lack in boar rations caused the degenerative changes in seminal glands, low male germ cells concentration and lowering of spermatozoon motility, which subsequently decreased their producing efficiency. Research showed, that selenium inclusion in premix KS-1 structure in quantity of 30 mg per 1 kg in comparison with premix in 20 mg dose have improved the yielding productivity of mature boars: the average quantity of male germ cells per one ejaculate increased on 17,2%, the average quantity of born pigs from per one sow increased on 4,8%. The additional profit per one boar was on 6,06% higher than in control experiment

Development of a new method of boar evaluation taking into account their beef-making and fattening qualities as well as their posterity viability for the further selection of the best ones and for the culling and ranking of the worst ones was realized in the conditions of a large pig-breeding complex of the Republic of Belarus. Scientific and economic experiment was realized at the JSC Sozh, Gomel region (Belarus) at the pig-breeding complex with 108 thousand livestock heads of annual fattening. At a finishing stage of sow hybridization the combinations of Large White х Landrace and Large White х the Belarusian Meaty breeds were inseminates by boars of 990 synthetic lines (N11151 and N11146), the Belarusian Meaty breed (N3495), Landraces of the Polish (N40, N37, N78) and German selection (N11262, N11263, N11266), and also by a hybrid boar of 990 lines х Petren (N11145). Sow insemination was realized in three technological groups. Sows were selected taking into account their breed, age and last productive ability in order to avoid inbreeding. At the same time, each boar was checked up on the breeding stock for identical quality. The final estimation of boars was stated at the stage of achievement by their posterity of selling weight (before sending to a meat processing plant). The offered method made it possible to get an objective comparative estimation of breeding characteristics of tested boars in the conditions of a complex

The influence of various light regimes on productive indices of broiler chickens cultivation of СОВВ cross taking into consideration the course of some exchange processes was studied in the conditions of the Republic of Belarus. There were formed 4 groups of one-day-old chickens with the approximately identical body weight. For the chickens of a control group there was used the standard for Belarusian poultry farms light regime, i.e. 23 hours of light and 1 hour of darkness (23L:1D), in three experimental groups there were used the following light regimes: first - (3L:1D) х 6, second - (2L:1D) х 8, third - (1L:1D) х 12. The predetermined conditions were set by means of filament lamps with 15 W capacity. Throughout the whole experiment there was realized the identical feeding level for all groups: during the first growing period (1-30 days) chickens were fed with mixed fodder PK 5B containing 22% of crude protein and 296,6 kcal of exchange energy, during second period (31-42 days) - PC 6B containing 20% of crude protein and 332,2 kcal. In the applied mixed fodders there was used enzyme Rovabio. Research results showed that metabolic processes occurring in chicken body in the majority opf cases depended on application of various light regimes. Interchange of light and darkness periods (3 hours of light and 1 hour of darkness) х 6 at light exposure in 15 lk rendered the positive effect on the activity of endocrine systems of chickens of СОВВ crosses. In mentioned above group of chickens the hormones directed their metabolic processes towards increasing the productive indices, namely: daily average gain of chickens of the first group was authentically higher than the same index in the second and the third groups on 13,6% and 17,9%, respectively

Research of the peculiar features of correlation parameter of production indices of 870 mongrel inbred sheep with the various inbreeding coefficients was realized in the conditions of the Republic of Belarus. In course of study there was stated the one-sided influence of inbreeding on phenotypic indices of pair, individual and cumulative pair correlation genetic correlations of sheep productivity. The majority of them were the statistically authentic values with P less than 0,1 - 0,001. It was stated that coefficient variability of genetic correlation of wool productivity rendered influence on sheep inbreeding degree among which there were marked off animal units with inbreeding in degree of consanguinity with the coefficients of higher statistical confidence (with P less than 0,01 - 0,001) than animal units with degrees of close or low relationship and outbred animal units - (P less than 0,1 - 0,01). The majority of ewe productive quality correlation factors with a different inbreeding degree proved to be positive and authentic and could be used for an estimation of correlations between traits in selection process for population perfection