An experiment was conducted to compare the bioavailability of dl-alpha-tocopherol acetate (TA) with that of dl-alpha-tocopherol nicotinate (TN) when administered to sheep, as a single dose, either into the rumen or the peritoneal cavity. A total of 16 sheep were used in a factorial design, with 4 sheep/treatment at the interaction level. In addition, 5 sheep that received no supplemental alpha-tocopherol, were euthanatized at the end of the trial to provide baseline data for tissue alpha-tocopherol concentrations. Curves were fitted to the plasma alpha-tocopherol concentration values, taken over 180 hours after administration of the esters. Availability of TA was greater than TN, as evidenced by the significantly higher curve parameter values (P < 0.05) and tissue concentrations (P < 0.05). Route of administration had a marked effect on availability of TA (P < 0.001), but not of TN.

Oxytetracycline (OTC) pharmacokinetic values in plasma and bile were ascertained after IV administration of the drug. At 6 hours after administration of 1 mg of OTC/kg of body weight, 2.15% of the dose was found in the bile and 37.6% was found in the urine. At 2 hours after administration, the peak bile-to-plasma OTC concentration ratio was 60:1. Bioavailability of OTC was 47.6% when it was administered orally to fasted turkeys and was 9.4% when administered to fed turkeys.

Pharmacokinetic variables of skeletal muscle creatine kinase (CK) activity after IV administration of a muscle extract; CK bioavailability after IM administration of the muscle extract; and effect of IM administration of saline solution, to appreciate the possible release of CK consecutive to muscle puncture, were determined in 6 cows. A general equation for the quantitative estimation of skeletal muscle damage also was derived. Administration of saline solution IM had no effect on plasma CK activity (ANOVA, P > 0.05) in any of the cows. After IV administration of the muscle extract (150 U/kg of body weight), mean volume of the central compartment, plasma half-life, and plasma clearance of CK were 0.027 +/- 0.007 L/kg, 520 +/- 109 minutes, and 6.43 +/- 2.29 ml/kg/h, respectively. After IM administration (150 U/kg), mean bioavailability of CK was 51 +/- 17% and maximal plasma CK activity (500 +/- 97 U/L) was observed at 454 +/- 131 minutes. The rate of CK activity entry into plasma was determined by use of deconvolution analysis. Two peaks were observed; the first appeared before the 30th minute after IM administration, and the second appeared at 3.3 +/- 1.1 hours. Amplitudes were 6.31 +/- 4.45 and 6.57 +/- 3.08 U/kg/h, for the first and the second peaks, respectively. The quantity of CK liberated from control muscle was 0.69 +/- 0.12 U/kg/h, corresponding to a normal daily catabolism of 5.8 +/- 1.0 mg of muscle/kg. From these results, the following equation can be proposed to determine the corresponding mean equivalent of destroyed muscle (Qmuscle, test article) after IM administration of a test article: Qmuscle, test article (g/kg) = 4.41 X 10(-6) AUC (U/h/L), with AUC being the CK plasma activity area under the curve.

The pharmacokinetics and bioavailability of rifampin were determined after IV (10 mg/kg of body weight) and intragastric (20 mg/kg of body weight) administration to 6 healthy, adult horses. After IV administration, the disposition kinetics of rifampin were best described by a 2-compartment open model. A rapid distribution phase was followed by a slower elimination phase, with a half-life (t1/2[beta]) of 7.27 +/- 1.1 hours. The mean body clearance was 1.49 +/- 0.41 ml/min.kg, and the mean volume of distribution was 932 +/- 292 ml/kg indicating that rifampin was widely distributed in the body. After intragastric administration of rifampin in aqueous suspension, a brief lag period (0.31 +/- 0.09 hour) was followed by rapid, but incomplete, absorption (t1/2[a] = 0.51 +/- 0.32 hour) and slow elimination (t1/2[d] = 11.50 +/- 1.55 hours). The mean bioavailability (fractional absorption) of the administered dose during the first 24 hours was 53.94 +/- 18.90%, and we estimated that 70.0 +/- 23.6% of the drug would eventually be absorbed. The mean peak plasma rifampin concentration was 13.25 +/- 2.70 microgram/ml at 2.5 +/- 1.6 hours after dosing. All 6 horses had plasma rifampin concentrations > 2 microgram/ml by 45 minutes after dosing; concentrations > 3 microgram/ml persisted for at least 24 hours. Mean plasma rifampin concentrations at 12 and 24 hours after dosing were 6.86 +/- 1.69 microgram/ml and 3.83 +/- 0.87 microgram/ml, respectively. We tested 162 isolates of 16 bacterial species cultured from clinically ill horses for susceptibility to rifampin. All strains of coagulase-positive staphylococci, Streptococcus zooepidemicus, Str equi, Str equisimilis, Rhodococcus equi and Corynebacterium pseudotuberculosis were highly susceptible to rifampin (minimal inhibitory concentration [MIC] less than or equal to 0.25 microgram/ml).

Japanese millet (Echinochloa frumentacea) growing and yielding capacity was estimated in single and mixed sowings cultivated on sod-podzolic light loamy soils in the conditions of the Republic of Belarus; as well as comparative evaluation of silage quality and determination of digestibility of nutrients. Field experiment with forage crops was realized in threefold replication in accordance with the following scheme: Japanese millet (100%); Japanese millet (70%) + vetch (Vicia) (30%); Japanese millet (70%) + lupine (Luoinus) (30%); Japanese millet (70%) + pea (Pisum) (30%); Japanese millet (70%) + soybean (Glycine max) (30%). Research results showed that mixed sowings of Japanese millet with bean cultures made it possible to obtain higher yields than single sowings on 5,9-15,6%. Silage made of Japanese millet with bean culture contained higher amount of crude protein on 2,73-3,98% in comparison with silage which was produces only from Japanese millet. Silage produced from Japanese millet mixture with high protein crops had high energy and protein value: 0,90-0,92 fodder units; 9,47-9,59 mJ of metabolic energy per 1 kg of dry matter and 102-103 g of digestible protein per 1 fodder unit

In the conditions of application of enzyme preparations there is the possibility of inclusion into mixed fodders structure of such cheap fodder grains as rye. Determination of the optimal dose of introduction of the liquid enzymatic fodder additive (xylanase – 8800 units; phytase – 600 units; cellulose – 880 units; r-gluco – 4000 units; a- amylase – 200 units) and its influence on stores productivity during the completion of growing and fattening periods was realized in the conditions of the Republic of Belarus. Research results showed the following: inclusion into mixed fodders of the increased amount of rye grain (without the enzyme additive) for stores feeding during the completion of growing (20%) and fattening (30%) periods did not render negative influence on experimental animals; the optimal dose of the trial enzyme for stores during the completion of growing period - (SK-21 including rye grain - 20%) was 200 ml per 1 t of mixed fodders; the optimal dose of the trial enzyme for stores during the fattening period (KDS-26 including rye -30%) was 150 ml per 1 t of mixed fodders. Application of the experimental fodder additive promoted the increasing live weight gain. There was noted the tendency of the positive influence of the analyzed enzyme on dry and organic matter, fat, dietary fibre and nitrogen-free extractive substances digestibility

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 was determined the productivity and foraging advantages of fodder galega (Galega officinalis) in comparison with the traditional perennial leguminous grasses (alfalfa (Medicago sativa); alsike clover (Trifolium hybridum); cookshead (Onobrychis viceaefolia)) and influence of the analyzed crop of state and internal microbiota of agricultural animals. There was studied the qualitative structure of galega in accordance with the phases of crop development and its influence on physiological functions of animals. It is established, that in the conditions of northern region of Belarus the fodder galega provided the yielding capacity of dry matter of 11,3 t/ha that exceeded the indices of alfalfa on 13,9%, alsike clover - in 2,7 times and cookshead - in 2,1 times. By the third decade of May it formed 18-20 tons green mass that made it possible to feed animals on 10-15 days earlier, than with other leguminous grasses. High degree of leafage (65,7%) preconditioned its high nutritional value. Fodder galega has high level of calcium, potassium, phosphorus and some microelements: copper, zinc, manganese, cobalt. Studying of vitamin value of fodder galega showed that its green mass was vitamin-rich, had enough of irreplaceable amino acids. It was established, that hay of fodder galega had high level of the non-decomposed protein (68,6-71%) that was very important for feeding of highly productive cows. It increased the level of crude protein in experimental animals on 8%.

Belarus is included into number of the leading countries of the world which provide the increasing of the expansion rates of milk production and dairy products on a per capita basis. However, the agricultural enterprises of the Republic of Belarus annually spend approximately 800 thousand tons of whole milk that makes about 20% from the general milk yield for manufacturing expenditures in the process of livestock operation. The purpose of research was working out of a new premix structure and zootechnic requirements to its use in structure of milk replacer, produced on hydrodynamic installation. The optimum doses of amino acids, vitamins and mineral substances promoted the increasing of calves daily average weight gain during the dairy period on 5,4% (788,5 g instead of 748,1 g), reducing of expenses for forages per 1 kg of weight gain - on 6,5% (2,9 fodder units against 3,1 fodder units) and the decreasing of the prime cost production for fodder expenses - on 4,7%. There was presented the composition and nutritive value of the analysed whole milk replacer. Usage of local sources of protein-fatty raw materials of plant origin, and also secondary resources of processing of whole milk in the content of milk replacer for young cattle allows to completely refuse from expensive components delivered from abroad and to lower their cost

Research on preserving ability of the biological preserving agent Bioplant for grass and maize silage making was realized in the conditions of the Republic of Belarus. Application of Bioplant in course of grasess and maize encilaging promoted the faster accumulation of the significant amount of milk acid and decreasing of рН up to 4,1-4,2. Silage which was prepared with preserving agent Bioplant corresponded to the top grade of quality. Application of Bioplant for preparation of siloed forages promoted the reduction of losses at their storage. For example, in grass-legume and cereal silage there was a reduction of dry matter losses in comparison with control silage - on 4,7 and 4,2%, crude protein - on 5,6 and 5,0%, respectively. In maize silage the addition of the preserving agent there was stated the decreasing of nutrient losses in comparison with the control: dry matter - on 5,2%, crude protein - on 6,2%. Feeding of wedder hogs with the silage preserved by the preserving agent Bioplant provided higher digestibility of crude protein in comparison with the control group: on 3,2% in the conditions of grass-legume silage use, on 2,4% - in the conditions of feeding with cereals, and on 2,9% - in the conditions of feeding with maize silage