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.

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.

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

Appraisement of new mixed fodder formulas for the fattening performance test was realized in the conditions of the Republic of Belarus by the example prevailing in the country Large White breed. Barley (Hordeum vulgare) proved to be one of the main components in swine feeding in Belarus. Forage wheat in mixed fodders for the fattening performance served a basic energy source and contained less dietary fibre than barley, as well as less concentration of antinutrients which interfere with digestion of rations than others crops (rye, triticale). Soybean and sunflower oil meal were included into analysed mixed fodders as the protein sources. Application of new mixed fodder formulas for fattening control realization according to the technical specifications of the Republic of Belarus 600039106.044 - 2007 was realized by the example of gilts of pigs of Large White breed. Research results showed that new studied formulas made it possible to obtain the higher intensity of swine development indices (on 52-72 grams) in comparison with the traditional formulas of mixed fodders (technical specifications of the Republic of Belarus 06093149.065-2000). New mixed fodder recipes did not render harmful effect on health and safety of livestock. At the same time, the analysed recipes of mixed fodders did not authentically influence the carcass indicators (carcass length, fat thickness, loin eye area, ham weight, slaughter yield)

In conditions of the Republic of Belarus much attention is given to optimization of energy and protein content in diets of dry cows. Analysis of the influence of different energy and protein ratio in dry cows diets on their productivity was realized. Increasing of protein and energy balance standards of dry cows during the winter period on 10 and 15% at the expense of introduction of protein, vitamin and mineral supplements (PVMS) made it possible to increase the daily average weight gain of animals on 5,4% and 12,2%, live weight of calves at a birth on 3,6% and 8,1% and their daily average weight gain over the first month - on 3,9% and 12,1%, respectively. Feeding with PVMS produced on the basis of peas and rape made it possible to raise the digestibility of nutritive substance on 1,4-14% and accessibility of all mineral substances on 0,4-10%. The increasing of energy and protein ratio on 15% in diets of pregnant dry cows rendered the positive effect on dairy efficiency. Fodder expenses for fodder unit production decreased on 5,5 and 6,8%, respectively. Inclusion of PVMS in mixture with pea and rape flour for dry pregnant cows during the summer period made it possible to raise their live weight on 5,9% and 9,7%, weight of calves at birth on 4,2% and 7,3%, and their daily average weight gain - on 5,7 and 9,4%. Optimization of power and protein fodder of pregnant dry cows promotes the increasing of milk yields in the first 100 days of the subsequent lactation on 5,1% and 9,9% and the decreasing of forage expenses for production unit on 4,6-9,1%

There was studied the width of distribution and peculiarity of clinical manifestation of mineral exchange diseases at pregnant sows, and also perfection of preventive actions at pathology of mineral metabolism in the conditions of prophylactic medical examination. Results of research have shown, that diseases of mineral metabolism widespread (84,7%) among pregnant sows in the conditions of industrial production, are most extended scarce conditions on Zn (17,7%) and Fe (22,5%). Clinically this insufficiency was expressed by oppression, appetite distortion, occurrence on a skin of specifically red stains correct roundish the form: with the clarified sites in the centre, are registered as abortions at final stages of pregnancy. It is established, that the way of preventive maintenance of hypomicroelementosis of pregnant sows with use of chelated forms of microelements is more preferable than sows, as reduces percent of clinical display of Zn and Fe deficiency, stabilize level of hematological and biochemical indicators of blood more effectively, and also raise industrial indicators of pregnant sows. | Целью работы было изучение широты распространения и особенностей клинического проявления заболеваний минерального обмена у супоросных свиноматок, а также совершенствование профилактических мероприятий при патологии минерального обмена веществ в условиях диспансеризации. Результаты исследований показали, что болезни минерального обмена веществ широко распространены (84,7%) среди супоросных свино¬маток в условиях промышленного производства, наиболее распространены дефицитные состояния по Zn (17,7%) и Fe (22,5%). Клинически эта сочетанная недостаточность выражалась угнетением, залеживанием, понижением и извращением аппетита, появлением на коже специфически красных пятен правильной округлой форма: с просветленными участками в центре, зарегистрированы так же аборты на конечных стадиях супоросности. Установлено, что способ профилактики гипомикроэлементозов супоросных свиноматок с использованием хелатных форм микроэлементов предпочтительнее, поскольку сокращает процент клинического проявления дефицита цинка и железа, эффективнее стабилизируют уровень гематологических и биохимических показателей крови, а также повышают производственные показатели супоросных свиноматок.

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%.

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