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)

Nowadays in connection with an interdiction for antibiotics use in animal feeding it is very actual to work out and apply new forms of probiotic preparations which should be as ecologically safe and harmless both to people and animal products. Probiotics make it possible to improve the digestibility of nutritive substances of forages, normalize metabolism, enrich with biologically active substances that promotes the increasing of their productivity. In the Republic of Belarus the probiotics are produced in the obviously insufficient quantity that creates problems of young stock livability. Influence of application of Akozil and Sublicin probiotics in diets of suckling calves on biochemical parameters of blood serum was analysed. It was stated that use of the analysed probiotics made it possible to decrease the level of urea and total cholesterol, to increase of the total protein content in blood serum of the experimental calves. There was noted the increasing of glucose level in blood serum of calves fed with Akozil. There was marked the tendency of more optimal level of calcium and phosphorus in calves having Sublicin in their diets. The obtained results testified the normalization of metabolic processes taking place in calves which were fed by the mentioned above probiotics

In process of animal husbandry intensification much attention should be given to maintenance of the high-grade balanced feed of animals. Forage supplement Profat (Protected Fat) is a protected fat in dry-sand mould with 84% of fat content. Application of 0,5-0,8 kg of dry fat supplement in cows diets per 1 head a day (4,7-10,0% in mixed forage content) promotes the increasing of prime cost of milk yield with basic fatness at 1,8-2,8% within fatness growth at 0,1-0,24% without protein content decrease. During the analysis of morphological and biochemical blood structure there was not established any considerable inter-group distinctions. At the same time, it is necessary to notice, that in blood of animals of two experimental groups there was stated a little bit higher protein content. However, in proportion to application of experimental fat additive up to 0,8 kg per head a day the protein content decreased. The increased number of erythrocytes and hemoglobin content in blood of animal of trial groups proved the strengthening of metabolic processes. In blood of trial groups it was noted high quantity of vitamin A and phosphorus as well as lower amount of calcium

There was realized the estimation of influence of application of biometals in a ration of chickens-broilers of different age on the content in their blood macro-and microelements. It is possible to make the conclusion, that in blood of chickens-broilers the tendency to decrease with the years concentration of calcium and magnesium, to increase of level of phosphorus, zinc and copper, and also increase the content of cobalt with 23-day age to 33-day and its insignificant decrease by 45 day of a life of chickens takes place. At the same time application in a ration of chickens-broilers of biometals sodium-ferrum-ethylenediaminetetraacetate (Na-Fe-etda) from calculation of 2,5 mg/kg, sodium-zinc-ethylenediaminetetraacetate (Na-Zn-etda) - 5,5 mg/kg, sodium-cobalt- ethylenediaminetetraacetate (Na-Co-etda) - 5,5 mg/kg and sodium-cuprum-ethylenediaminetetraacetate (Na-Cu-etda) - 3,5 mg/kg of body weight in the basic weight led to small increase of level macro- and microelements in blood of chickens-broilers and did not render negative influence on safety and a gain of body weight of chickens in trial group. Data on concentration of macro- and microelements in blood and a body weight gain of chickens-broilers are presented. | Целью работы является оценка влияния применения биометаллов в рационе цыплят-бройлеров разного возраста на содержание в их крови макро- и микроэлементов. Можно сделать заключение, что в крови цыплят-бройлеров имеет место тенденция к снижению с возрастом концентрации кальция и магния, повышению уровня фосфора, цинка и меди, а также увеличению содержание кобальта с 23-дненвного возраста к 33-дневному и незначительному снижению его к 45-му дню жизни цыплят. В то же время применение в рационе цыплят-бройлеров биометаллов натрий-ферум-этилендиаминтетраацетат (Na-Fe-etda) из расчета 2,5 мг/кг, натрий-цинк-этилендиаминтетраацетат (Na-Zn-etda) - 5,5 мг/кг, натрий-кобальт-этилендиаминтетраацетат (Na-Co-etda-) - 5,5 мг/кг и натрий-купрум-этилендиаминтетраацетат (Na-Cu-etda) - 3,5 мг/кг живой массы в основной своей массе приводило к небольшому повышению уровня макро- и микроэлементов в крови цыплят-бройлеров и не оказывало негативного воздействия на сохранность и прирост живой массы цыплят опытной группы. Представлены данные по концентрации макро- и микроэлементов в крови и прирост живой массы цыплят-бройлеров.

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 analyzed the efficiency of feeding of a new protein vitamin and mineral additive containing national local protein and mineral raw material sources in diets of 12-16-month old heifers. Instead of sunflower extraction cake the heifers were fed with the protein-vitamin and mineral additive which contained rape grain (Brassica napus), lupine (Lupinus) grain as well as mineral and vitamin additives based on halites, phosphogypsum, phosphate, sapropel and premix in dose of 20-25% by weight as a part of mixed fodders. The additive was used against the background of rations with green mass from a cereal and leguminous mixture - 56-57%, mixed fodder - 36-37%, molasses - 6-7%. In accordance with nutritional value indexes the proposed additive rendered the positive influence on forage consumption, indexes of ruminal digestion, as well as on the morphological and biochemical blood composition. It application made it possible to obtain daily average weight gains of animals at the level of 812-827 grams within forage expenses of 7,0-7,2 сentner of fodder units. Inclusion of the protein vitamin and mineral additive with local protein and mineral raw materials in rations of calves made it possible to lower the mixed fodder cost price on 12-15% and the cost price of 1 centner of gain during the summer period - on 11-13%.

In the conditions of the Republic of Belarus there were determined the fattening and slaughter qualities of swine as well as the evaluation of their pork production in the conditions of inclusion into their diets of a biologically active substance on the basis of field caraway (Carum carvi L.). Research results showed that in the production conditions the administration of the biologically active additive in a dose of 7 gram per 100 kilogram of live weight of pigs made it possible to increase their daily average gain from 627,9 grams in a control group up to 687,2 grams (or on 9,44% (P less than 0,999)), to increase their preslaughter and slaughter weight respectively on 3,76% and 6,42%, dressing percentage and carcass yield – respectively on 1,71 and 1,67%. According to the indexes of meat quantity in diverting weirs of the experimental pigs surpassed the control group on 3,03%, or 2,70 kg. The fat content in the half carcasses of the experimental group was authentically lower than the indices of control animals on 0,48 kg or on 2,18%. The hock weight of experimental animals with high confidence exceeded pigs of the control group on 1,15 kg, or on 10,45%. They practically did not differ from the control group according the indexes of thickness of pork fat at the level of 6-7 chest vertebras, and in the area of a muscular eye surpassed them on 4,0 square сm or on 7,72%.

In the conditions of the Republic of Belarus there was realized a comparative estimation of efficiency of the increased level of phosphorus, calcium, copper, zinc, cobalt, iodine and vitamins A and D in comparison with regulations of the All-Union Academy of Agricultural Sciences of the Soviet Union (1985) and the Russian Academy of Agricultural Sciences (2003) for pregnant cows in a dry period at summer feeding. Also, there was studied the digestibility of nutritive substances of forages in cow diets, as well as the evaluation of their after-effect on revelation of dairy productivity indexes in the subsequent two months of lactation, biochemical blood indexes and payment of forage byproducts. As a result of application of moderately increasing levels of macro- and trace elements, vitamin D, and phosphorus in particular on 10,0% in comparison with 15,0% and existing level in rations of pregnant cows there was stated a slight decreasing of pregnancy duration of animals on 0,10 day. Also, there was marked an increasing of milk yield of milk with 4% fat content on 1,64% and 4,48%, the growth and development of calves in the prophylactic period on 4,18 and 4,61%,; and the was an improvement of organic substance digestibility on 1,52 and 1,78%. Besides, there was revealed more moderate number of leukocytes and content of crude protein.

In the conditions of the Republic of Belarus there was studied the efficiency of application of forage chemical preservatives Kormoplyus-1, Kormoplyus-2, and Kormoplyus-3 for grass fodder conservation. The analyzed preservatives contained acetous acid, urotropine and sodium acetate (only in Kormoplus-2). In course of the study there were established experimental batches with the studied sreservative; there was determined a chemical composition of prepared forages; in physiological and scientifical and economic experiment there was analyzed the feeding efficiency of cereal ensilage. Research results showed that application of preservatives Kormoplyus-1 and Kormoplyus-2 2 for preparation of cereal ensilage made it possible to receive a high quality ensilage and to increase the dry matter safety on 4,2-8,7% and protein on 12-9,4% on comparison with storage without preservatives. Also, it made it possible to increase the digestibility of dry matter in cattle diets respectively on 5.5% and3.7%; organic substance - on 5.5% and 4.0%; fibre - on 16,5% and 15,0%, and also to increase nitrogen deposition on 17,4 and 20,8%. Feeding with forages preserved with Kormoplyus-1 and 2 did not render negative influence on a health state and biochemical indices of animal blood.

Investigation of quality and quantity indexes of sperm production of boars of Yorkshire, Landrace, Duroc breeds of Danish selection was realized in the conditions of the Republic of Belarus. Quality and quantity indexes were analyzed in accordance with ejaculate volume, spermium concentration and activity at different age-specific periods in the comparative aspect. Thorough analysis of quality indexes (ejaculate volume; spermium concentration; spermatozoon motility; sperm quantity) of semen production of studied breeds at different age-specific stages (before 7 months old; 7-10 months; 10-12 months; 12 months and older) was presented. Coefficients of variation of valuation indexes of semen production were stated. Research results showed that the lowest ejaculate volume was typical for boars of Duroc breed, but the quantity of spermium in ejaculate of this breed since 10-month old age was the highest – 92,6 milliard, that made it possible for this breed of boars to take premier place according to the index of spermium quantity in ejaculate. The same index for boars of Landrace and Yorkshire at age of 12 months old and older was 77,5 and 76,3 milliards, respectively. High variability of indexes of evaluation of semen production was due the reason that the research was taking place at the period of formation of productivity over the whole pig stock. Research results proved that indexes of semen production of producer boars of Yorkshire, Landrace, Duroc breeds of Danish selection depended on the breed and high variability indexes