Influence of various levels of the organic form of selenium of Sel-Pleks on the formation of reproductive function of breeding bull-calves is studied in the conditions of the Republic of Belarus. Feeding of organic selenium to bull-calves promoted volume increase of ejaculate on 5,0%, quantities of male germ cells in ejaculate - on 9,1% and concentration of male germ cells in ejaculate - on 7,5% in comparison with animals in which rations sodium selenit was used. Application in winter period of the premix with inclusion of selenium in a dose of 0,4 mg per 1 kg of a dry matter of a ration allows to increase the quantity and quality of sperm of bull-calves: volume ejaculate - on 9,5%, concentration of male germ cells in ejaculate - on 16,4% (Р less than 0,05) and activity of male germ cells - on 8,9% (Р less than 0,001). Increasing of a dose of selenium up to 0,4 mg per 1 kg of a dry matter in rations of bull-calves in summer period allows to increase quantity and quality of sperm. At bull-calves of the third experimental group the ejaculate volume has increased on 4,5%, concentration of male germ cells in ejaculate - on 15,7% (Р0,05) and activity of male germ cells - on 7,3% (Р less than 0,001).

In the conditions of Vitebsk region of the Republic of Belarus there was realized a programme on creation of breed type of Hereford cattle. In course of the study there were realized experiments on increasing the number of livestock of beef cattle breeding by means of accumulation cross breeding of black-and-white cattle with Hereford producer bulls as well as by means of pedigree breeding of Hereford cows and calves imported from Russia and Hungary for the production of marbled beef. Breeding background of obtained purebred calves was determined by DNA-testing method in accordance with the international standard of certification. Into the breeding group of created meat type of Hereford cattle in the analyzed cattle breeding enterprise there were selected 1183 heads, including 24,2% of purebred animals and 17,2% hybrids of the third and fourth generations. The breeding estimation thoroughbred Hereford cattle showed that all producer bulls belonged to the class elite-record. The percentage of cows and heifers of the elite-record class was 89,3% in the conditions of growing number of a thoroughbred livestock on 98 heads. Purebred young stock in number of 45 heads and their mother passed the estimation of their origin by DNA method-testing.

On the basis of the spent research high enough preventive efficiency of Ehrakond application, low intensive laser radiation together with a constant magnetic field is defined that allows to recommend them for wide application in the program of immunocorrection of an organism of agricultural animals. At the first stage of the research in immune deficiency when in blood of newborn calves almost there are no antibodies, influence on biologically active points of an udder of cows (intensity 10 mW/square cm, expositions of seconds) has made positive impact on increase of immune properties of colostric milk. Use of immunostimulants Ehrakond also has increased immunocompetent properties of cow milk (7,5 mg on 1 kg of body weight once a day within 15 days). At feeding of colostrum the physiological condition, growth and development of calves have considerably improved. In the second (when colostric protection factors in an organism decline, and own organism forms them insufficiently) and the third (decrease in immune reactance at changes in feeding and the maintenance of calves) immune deficiency, application of immunostimulants Ehrakond and influence of low intensive laser radiation together with a constant magnetic field on reflexogenic zones on a young growth organism has made positive impact indices of natural resistance of calves. It has led to activization of factors of natural nonspecific protection of an organism that has considerably improved a physiological condition and has increased natural immunity of an organism to diseases. However, the best results on natural resistance, efficiency and safeties of calves have been reached at an irradiation at the BAP initial stage of a mammary gland at cows by low intensive laser radiation together with a constant magnetic field, with the subsequent bottle-feeding of the irradiated colostrum to newborn calves; in 10 days of a life to calves the preparation Ehrakond was entered. | На основании проведенных исследований определена достаточно высокая профилактическая эффективность применения Эраконда, низкоинтенсивного лазерного излучения совместно с постоянным магнитным полем, что позволяет рекомендовать их для широкого применения в программе иммунокоррекции организма сельскохозяйственных животных. На первом этапе исследований в период иммунного дефицита, когда в крови новорожденных телят почти отсутствуют иммуноглобулины, воздействие на биологически активные точки вымени коров (интенсивность 10 мВт/см2, экспозиции секунд) оказало положительное влияние на повышение иммунных свойств колострального молока. Использование иммуностимулятора Эраконд также повысило иммунокомпетентные свойства молока коров (7,5 мг на 1 кг живой массы один раз в сутки в течение 15 дней). При скармливании колострального молозива значительно улучшились физиологическое состояние, рост и развитие телят. В период второго (когда колостральные факторы защиты в организме угасают, а собственный организм образует их недостаточно) и третьего (снижение иммунной реактивности при изменениях в кормлении, содержании телят) иммунного дефицита, применение иммуностимулятора Эраконд и воздействие низкоинтенсивного лазерного излучения совместно с постоянным магнитным полем на рефлексогенные зоны на теле молодняка оказало положительное влияние показатели естественной резистентности телят. Это привело к активизации факторов естественной неспецифической защиты организма, что значительно улучшило физиологическое состояние и повысило естественную невосприимчивость организма к болезням. Однако, наилучшие результаты по естественной резистентности, продуктивности и, сохранности телят были достигнуты при облучении на начальном этапе БАТ молочной железы у коров низкоинтенсивным лазерным излучением совместно с постоянным магнитным полем, с последующим выпаиванием облученного молозива новорожденным телятам; через 10 дней жизни телятам вводили препарат Эраконд.

In the conditions of the Republic of Belarus as a result of task-specific selection and breeding work there was developed and approbated Berezinsky breed type of Belarusian meaty breed. Sows of the studied breed type were notable for high indices of reproductive signs: the average multiple pregnancy in three breeding swine herd was 11,1 pigs per farrowing; milkability - 55 kg, litter size at weaning stage at 35-day age - 87,1 kg. The predominancy over the forecast exponent indices made 4,7-5,7%. In course of the study there were analyzed the forecasted indexes of the basic breeding signs of Berezinsky breed type of Belarusian meaty breed for 2005-2010; productivity indices of the experimental sows; coefficient of variations of sow productivity.

In the conditions of the Republic of Belarus there were studied the productive and interior indexes of bull calves which were fed with dried distiller's grains. Inclusion into bull calves diets of the mixed fodder containing 33% of dried distiller's grains made it possible to increase the concentration of volatile fatty acids on 16-18%, albuminous nitrogen - on 4-7%, quantity of infusorians - on 16-17%, as well as to reduce the ammonia level in a ruminal liquid from 23,4 up to 17 mg%. Inclusion of 33% of dried distiller's grains into structure of mixed fodder and feeding the same quantity of fresh distiller's grains promoted increasing of nutrient digestibility on respectively 4,0-5,9% and 3,5-4,5%, nitrogen retention - on 13%. Increasing of level of dried distiller's grains in structure of grain forage up to 67% increased the digestibility of nutrients on 1,5-2% and nitrogen retention - on 4%. Substitution in mixed fodder for bull-calves of 33 and 67% of fodder grain by dried distiller's grains made it possible to increase daily average live weight gain of animals respectively on 10 and 4%. Feeding of dried and fresh distiller's grains at simultaneous introduction in rations of complex mineral additive promoted the activation of metabolic processes that was proved by increasing of crude protein of blood at 6-7% and 5-8%, as well as decreasing of concentration of urea - on 25 and 22% respectively. Use of 33% of dried distiller's grains as a part of mixed fodder for cattle young stock proved to be economically effective and allowed to lower the cost price of a live weight gain on 10-11%. Feeding with fresh distiller's grains allowed to lower the prime cost price on 7% and to receive additional profit.

In the conditions of the Republic of Belarus there was studied the yielding capacity and quality composition of nontraditional high-energy crops (sorghum and Sudan grass hybrid; millet (Panicum); white panicum (Japanese millet)) as well as there was developed a technology fodder conservation. In course of the study there was analyzed accumulation of nutrients in accordance with crop development phases and their quality composition; also there was determined a method of application of grass stands of the studied crops for their production use. It is established, that the most suitable for conditions of Vitebsk region from high-quality cultures is sorgho-sudan-grass hybrid which reaches phases of seed formation and provides productivity of dry matter more than 9 t/ha with humidity of green mass of 69% that is optimum for preparation of tinned forage. Sugar sorgho and grain is reached by phases of ear formation and have provided productivity of green mass of 25,9-25,7 t/ha, dry matter - 3,5 t/ha. To use double-cut sorgho-sudan-grass hybrid on a silo less effectively as the received green mass has high humidity (92%), and the general gathering of dry matter twice more low, than at single-cut use. At single-cut use the culture reaches phases of grain formation in which contains about 31% of dry matter that is favorable for conservation. Double-cut use of sorgho-sudan-grass hybrid is comprehensible at its cultivation in the green conveyor to use as green top dressing during the pasturable period. Japanese millet is better to use double-cut as it has provided the maximum productivity of green mass of high quality (63,9 t/ha) and dry matter (9,1 t/ha), it is in 2,3 and 1,6% of time above, than at single-cut use. Single-cut crops of sorgho-sudan-grass hybrid are expedient for using as a component at siloing of galega orientalis. In an early phase of development (7-8 leaves) the new-mown green mass of sorgho-sudan-grass hybrid possesses toxicity on the bottom border of average degree, but in 2 hours after mowing the forage becomes not toxic. In later phase of development there is an accumulation of sugars, and new-mown mass of sorgho is nontoxical. Sorghum cultures contain high percent of non-decomposed protein - 58,3-84,6% that is very important in feeding of highly productive cows.

In the conditions of the Republic of Belarus there was created an adhesive antigen on the basis of bacterial suspension of Escherichia which were separated from culture media by means of purification and concentration on membranes UMP-300 and UMP-5 that made it possible to obtain a cleaned-up preparation the specific activity of which was in 2-4 higher that of the unpurified one. In course of the study there was developed a method of purification and concentration of adhesive Escherichia antigens with the help of membrane technology. There were obtained biologically active adhesive antigens E.coli K88, K99, F41, 987P; there were selected the ultrafiltration membranes providing the optimal selectivity and productivity of the process; there were studied the influence of some factors on the process of adhesins concentration by means of ultrafiltration method. During the experiments there was analysed the agglutinating activity of antigents prepared by different methods.

In the conditions of the Republic of Belarus there was realized a cultivation of pasteurellas by different methods in Hottinger broth in 37 deg C temperature in course of 24 hours. Tissue culture properties were studied in accordance with the character of bacteria growth in liquid nutritive media and at the agar surface. Research results showed that in 7 hours after cultivation in media with application of shuttel apparatus and addition of glucose it was possible to obtain the highest quantity of viable pasteurellas with a high degree of virulence. The obtained culture on the basis of obtained results was proposed to be used for the production of virulence antigen.

In the conditions of the Republic of Belarus there was studied the propagation of associative parasitic diseases of swine of different age-specific groups, as well as their influence on composition of microbial flora of large intestinal tract. As a result of realized studies in different age-sex groups of pigs there were revealed some monoinfections (A. suum; T. suis; Eimeria sp.) and associations (A. sum; T. suis; Eimeria sp.; Oesophagostomum dendatum; B. coli) in different ratio (depending on sex and age-specific groups). There were revealed a certain peculiar features in changing of microbiocenosis of large intestinal tract of swine under the influence of parasitic agents (namely, in cases of parasitic diseases caused by A. suum; T. suis; Eimeria sp.; O. dendatum; B. coli both in the form of mono infestations and in associations). These features were expressed by lowering of standard flora quantity (bifid bacterium and lactic acid bacillus) with a simultaneous increasing of the content of opportunistic coliform bacillus, aerobic bacteria, bacilli, and micromycetes.

In the conditions of the Republic of Belarus there was analyzed the metabolic status of cows in the finishing period of pregnancy, as well as influence of its disorders on clinical status and breeding and economic indexes of new-born calves. Research results showed in pregnant cows in interlactation period there was stated the development of subclinical poly-hyper trace element deficiencies. There was realized the analysis of indexes of trace elements metabolism in cow blood; blood indexes characterizing protein metabolism; as well as biochemical blood indexes characterizing the carbohydrate metabolism and functional state of liver and kidneys. In the conditions of subclinical poly-hyper trace element deficiencies of cows there were revealed the biochemical changes which showed the lowering of the functional activity of liver and intoxication. Economic and clinical indexes of calf crop were analyzed. Research results showed that in calves (obtained from cows with trace element deficiencies) in an early extrauterine life there statedthe development of a toxic form of dyspeptic disorder which was accompanied with high degree of young stock death.