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 were studied the most effective methods of diagnostics of genital forms of clamidiosis at cows in pregnancy, calving and the postnatal period. The description is resulted and the estimation is given methods of laboratory diagnostics, serological methods, a method of light microscopy, immunofluorescence, enzyme immunoassay, chlamydia allocation method on laboratory models, complement linkage reaction, hemagglutination reaction, a method of polymerase chain reaction. As a result of complex use of reaction of complement linkage reaction, on the basis of the analysis of clinical and histologic research, studying of a condition of immune system and nonspecific resistance of an organism it is possible to carry out successfully diagnostics of genital forms of clamidiosis at cows. | Целью исследований явилось изучение наиболее эффективных методов диагностики генитальной формы хламидиоза у коров в период беременности, ca и послеродового периода. Приведено описание и дана оценка методам лабораторной диагностики, серологическим методам, методу световой микроскопии, иммунофлюоресценции, иммуноферментному анализу, методу выделения хламидии на лабораторных моделях, реакции связывания комплемента, реакции гемагглютинации, методу полимеразной цепной реакции. В результате комплексного использования реакции связывания комплемента (РДСК), на основании анализа клинических и гистологических исследований, изучения состояния иммунной системы и неспецифической резистентности организма можно успешно проводить диагностику генитальной формы хламидиоза у коров.

In the conditions of the Republic of Belarus there was studied the activity of hepatic specific enzymes of blood serum of bull calves of black-and-white breed in course of application of various doses of zinc-containing preparations. Application of zinc-containing preparations led to multidirectional change of activity of hepatic specific serum enzymes. Application of Zinkovet preparation in dose of 1,8 g/100 kg of live weight made it possible to essentially grade the indexes of hepatic tissue affect. In the experimental group at animals there was marked the lowering in activity alanine-aminotransferase, serum glutamic oxalacetic transaminase and gamma-glutamyl transpeptidase. At the same time, there was noted the increasing of zinc-containing enzymes activity (sorbitol dehydrogenase and glutamate dehydrogenase). All these processes were caused by zinc inclusion into the metabolic process.

In the conditions of the Republic of Belarus there was studied the efficiency of application of national mineral additives (mineral feed additive produced on the basis of dolomitic meal) in rations of milking cows. In course of the study there were analyzed physical and chemical blood indexes; hematological indexes of cows; biochemical blood indexes; mineral composition of blood; natural resistance of cows. As a result of the realized study it was established, that an optimum dose of a dolomitic meal for milking cows during the winter period was 0,3% per dry matter of a diet. There was proved the possibility of increasing of a daily average milk yield of cows on 11,7%, fat and protein content in milk - on 0,04 - 0,06%, as well as lowering of quantity of somatic cells on 13,6%. Application of a national mineral additive rendered the positive influence on blood indices to what that was proved by increasing of erythrocytes (on 10,9%), thrombocytes (on 5,4%), haemoglobin (on 6,5%), crude protein (on 10,6%), and also macro- and trace elements. Introduction of a dolomitic meal into cow diets made it possible to increase the indices of natural resistance of cows on 0,5 - 4,0%.

In the conditions of the Republic of Belarus there was realized a comparative study of meat productivity of mongrel Gereford х black-and-white heifers ad purebred black-and-white heifers in the conditions of different levels of concentrated feedstuff in cattle diets; and determine the most efficient and long-term method of animal breeding for meat. Research results showed that breeding of meaty of hybrids of Gereford х black-and-white heifers of the second generation without using the feeding concentrates in their diets or on using rations with a low rate of feeding concentrates (10-20%) proved to be more effective, than breeding of purebred black-and-white herdmates (for which specific density of the concentrated forages in diets made up 20% through pregnancy). Hybrids on Gereford breed in accordance with meat productivity level surpassed the purebred black-and-white animals. The most considerable results were marked at hybrid heifers with relative density of concentrates in a ration of 20% which in accordance with slaughter weight indexes surpassed the herdmates of black-and-white breed on 39,1 kg or on 23,68%, in accordance with slaughter yield - on 8,2%, in accordance with fresh carcass weight - on 37,9 kg or on 23,8%, in accordance with weight of inner porc - on 1,19 kg or on 20,62%.

In the conditions of the Republic of Belarus there was realized a comparative study of peculiar features of influence of combined application of Khelavit preparation and protein-vitamin-mineral feed supplements Khendriks and Spaeta-kontsentrat on health status of cows and quality of obtained cow milk after application of these preparation for the preventive treatment of osteodystrophy. In course of study there were analyzed haematologic and biochemical blood indexes of cows after application of the experimental preparations. Results of physical and chemical indexes of milk were presented. Research results showed that the analyzed protein, vitamin and mineral feed supplements caused the normalization of biochemical blood indexes in comparison with animal of a control group. Besides, application of mentioned above drugs promoted the increasing of veterinary and sanitary quality and technological properties of produced milk.

In the conditions of the Republic of Belarus there was studied the influence of high degree of cow productivity on the course of down-lying and state of endocrine status of animals and their reproductive qualities. Application of veterinary preparations Katozal and Ovoton made it possible to control the functional activity of cow dam and ovary providing the increasing of cow reproduction qualities. Results of tests of estradiol-17 beta and progesterone in blood serum of experimental and control groups cows were presented. Application of Katozal and Ovoton veterinary drugs made it possible to cause heat and insemination of 86,5-91,3% of cows. At the same time, according to the results of the first insemination the highest results were obtained at cows with low productivity indexes – 60,9% and according to productivity increasing this index lowered up to 32,7% and 29,8%, respectively. According to the results of all insemination in cases of 3500-5000 kg productivity only 2 cows (8,7%) were nonbearing.

In the conditions of the Republic of Belarus there was studied the possibility of application of biotechnological methods of correction of sexual function of infertile cows and heifers (oestrus stimulation and synchronization) a dairy cattle breeding farms with high breeding productivity indexes and simultaneous metabolic function diseases. In course of the study there were applied clinical, cytodetection technique, haemotological, biochemical and analytical methods. Results of three-year studies of pathological metabolic disorders of cows (chronic acidosis; chronic ketoacidosis; dystrophic liver affection; renal irritation syndrome; disturbance of calcium and phosphorous ratio; trace element deficiencies; hypovitaminoses) were analyzed. Structure of obstetric-gynecologic pathology in experimental dairy cows herd was presented. Research results showed that high reproduction indexes of cows were the contributory cause for development of metabolic disorders. In such conditions for the efficient stock reproduction it was proposed to apply the mandatory hormonal stimulation of sexual function by means of application of the Ovsinkh scheme.

In the conditions of the Republic of Belarus there was realized a determination of an optimal time for cow insemination with the help of oestrus detector by Draminsky's method. In course of the experiment there were used black-and-white nonpregnant cows at the stage of oestrus (sexual heat). In course of the study there were used clinical, biochemical and hematological research methods. Dynamics of changing of estrous cycle slime depending on a day of sexual cycle was analyzed. Indexes of the reproductive function of cows in experimental and control groups were compared. Research results showed that revelation of cows with oestrus with the help of oestrus detector by Draminsky's proved to be efficient and informative. Insemination of animals at the stage when the resisting of oestrus mucilage after the minimal indexes (180-200) rose sharply up to the indexes 300-320 proved to be efiicient. This made it possible to realize single insemination of animals.

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.