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

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

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

In the process of monogastric animal feeding, including pigs, the special role is played by the quality of coarse grain crops as they compose 70-75% of swine ration structure. Determination of fodder productive effect on fattening swine was realized in the conditions of the Republic of Belarus. The basis of the analyzed fodder was formed by fodder grain of extra fine grade. Research results showed the following: inclusion of extra fine grade barley (Hordeum vulgare) and wheat (Triticum aestivum) (chosen in accordance with the standard of the Republic of Belarus) into all-in-one mixed fodders SK-26 and SK-31 for fattening swine made it possible to obtain higher productive capacity of the experimental animals in comparison with the identical mixed fodders containing barley and wheat of other grades (chosen in accordance with All-Union State Standard 28672-90); in the experimental groups the average daily weight gain in course of the fattening period was on 34 grams higher, and the average selling weight of 1 head - on 4,1 kg than in the control group. Swine which were fed with the presented mixed fodders with grain extra fine grade showed fewer deviations from the rated value of metabolism (blood serum protein and its fractions, calcium, phosphorus, acid capacity) in comparison with the control 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

Research of possibility of application of sapropel (putrid mud) of the Chervonnoe lake (the Republic of Belarus) in diets of bred and milking sows as one of the ingredients of mixed fodders, as well as the evaluation of its influence of sow development and digestibility of nutritive elements were studied. Application of dry sapropel a source of energy, protein, mineral and vitamin nutritive elements for mixed fodder production rendered the positive influence on sows productive qualities: there was stated the increased number of born piglets on o,5 heads with a higher growing capacity; there was noted the increasing of coefficients of nutritive elements metabolism (crude protein – on 2,7%, crude fat – on 2,9%, free-nitrogen extracts – on 1,3%, and dietary fibre – jn 4,7%) with the simultaneous increasing of nitrogen, calcium, and phosphorous uptake by sows. Nutritional value of the analysed sapropel was 0,23 fodder units and 3,13 MJ of exchange energy per 1 kg of dry matter. Inclusion of 3% sapropel into mixed fodders for pregnant and suckling sows promoted the increasing of quantity of pigs at a birth, body weight of one pig to 3-week age and has ensured young growth with higher energy of growth. Use of sapropel in mixed fodders for sows makes active a metabolism and promotes increase of digestibility of the basic nutrients of a rations

Study of the regeneration processes and raising the efficiency of rape (Brassica napus) organs and tissues cultivation in vitro methods, as well as the achievement of a stable yield of proper regenerants were realized in the conditions of the Republic of Belarus. The obtained data specified the possibility of generation of rape finished regenerants in vitro culture without additional passages and transfers by means of effectively selected concentrations of phytohormones and biologically active substances, which made it possible to realize principles of totipotency and polarity of crop vegetative organs. On the explant part which was submerged into culture medium there was formed a root, and on opposite one - the morphogen structures. The possibility of obtaining rape regenerants from hypocotyls segments by straight regeneration was studied. Application of the analyzed substances considerably simplified and reduced the price of process of full regenerants formation, and made it possible to receive a wide spectrum of various forms that was important for selection process due to the opportunity to select valuable (in protein content) samples for the further studies and their inclusion into production process

Results of studies of the influence of two biological products produced on the basis of sapropel (putrid mud) of the Ganarata lake (Mostovski district, the Republic of Belarus) on quality of legume-grass silage were presented. It was established, that analyzed preparations could be used as the preserving agents for preparation of herbal forages. The preserving action of the preparations was caused by the intensification of lactic bacteria development in silaging mass for the account of humic acids, as well as by the fungicidal action of phenolic and carboxylic fractions of the preparation. Silage preparation in combinations with putrid mud preparations made it possible to lower the losses of a crude protein on 11,3-15,6%, sugar - on 33,3%, carotin - on 20% and to obtain forage with concentration of exchange energy 9,20-9,38 mJ per 1 kg of dry matter. Silage application in combination with biological products rendered positive impact on milking efficiency of cows, the average daily milk yields in the experimental cow groups were on 1,3-1,4 kg or 6,8-7,3% higher. Application of higher quality feeds made it possible to lower the expenses of forages on 0,04 fodder units. Research results proved that the analysed preparations from sapropel could be used as an efficient conservants for silage preparations. They made it possible to raise forage quality at the minimum expenses

Evaluation of maize (Zea mays) silage prepared in combination with biological preserving agent Laktotim and calculation of its economic efficiency were realized in the conditions of the Republic of Belarus. Application of Laktotim rendered positive influence on forage dry matter content, on nutritive substance safety, and made it possible to increase the organoleptic indicators of silage. Use of the maize silage prepared with the preservative in a cow ration has positively affected their dairy efficiency. Cow milk yields have raised on 4,5%. Application of the preparation for silage making of green maize mass proved to be economically worth. The realized toxicological estimation of biological preserving agent Laktotim did not reveal any signs of preparation toxicity. Introduction of the preparation into mice stomach in a single maximum dose (25000 mg/kg; 12500; 5000 mg/kg of body weight), as well as application of the preparation in mixture with water in ratio which in 100 and 200 times exceeded the standard ratio in plant green mass, did not cause destruction of experimental animals. According to classifications of All-Union State Standard 12.1.007-76, the preparation Laktotim belongs to the4 class of danger - low-hazardous substances (LD50 over 5000 mg/kg)

Balanced complete feeding proved to be one of the major conditions of animal productivity increase and improvement of their reproductive qualities. Full value of feeding could be obtained at the expense of forage quality improvement and perfection of structure of the rations providing the increasing of metabolic energy use by breeding bull-calves. Analysis of the efficiency of metabolic energy use by the replacement bull calves under conditions of various sugar and protein ratio was realized in the Republic of Belarus. Research results showed that enrichment of replacement bull calves (with 325-405 kg of live weight) rations with easy digestible carbohydrates (sugar and starch) in ratio of 32% from a dry matter ration, including 15% of stable starch made it possible to increase the transformation of metabolic energy into energy of body weight gain on 21,73 - 23,96 MJ or on 10,3%, that as a result correspondingly increased the daily average weight gains on 7,9% and reduced the expenses for forage energy for 7,1% counting on an energy unit. According to the ejaculate volume indices the bull calves of the second experimental group surpassed analogues of a control group on 14,8%, and according to sperm concentration indices - on 12%. The average quantity of the frozen doses of sperm has made 65%