Beef production in the Republic of Belarus could be competitive only in case of development of the specialized beef cattle breeding. Therefore, for the increasing of beef production and improvement of its quality in Belarus there was noted the necessity to use cattle beef breeds both in case of straightbred breeding, and in crossing with low income-earning Black-and-White cow stock. Research results showed that hybrid Gereford x Black-and-White breeds of the first and second filial generations showed higher reproductive abilities which were manifested in 105-120 days age reduction at the stage of the first insemination, 18-44 days reduction of service period, 0,07-0,1 times increasing of breeding efficiency index, 9,8-14,4% increasing of calf crop per 100 dams, and 14,4-16,4% increasing of young stock livability in comparison with the Black-and-White breeds calves. Research results showed that the non-heating season of the mongrel Gereford x Black-and-White heifer breeds of the first and second filial generations was 396-400 days, breeding efficiency index (rate of fertilization) - 1,29-1,32, breeding performance index - 85,4-90,0%, while for the at Black-and-White heifer breeds the same indices were 425 days, 1,29 and 75,6%, respectively

Results of studies of the influence of two biological products produced on the basis of sapropel (putrid mud) of the Ganarata lake (Mostovski district, the Republic of Belarus) on quality of legume-grass silage were presented. It was established, that analyzed preparations could be used as the preserving agents for preparation of herbal forages. The preserving action of the preparations was caused by the intensification of lactic bacteria development in silaging mass for the account of humic acids, as well as by the fungicidal action of phenolic and carboxylic fractions of the preparation. Silage preparation in combinations with putrid mud preparations made it possible to lower the losses of a crude protein on 11,3-15,6%, sugar - on 33,3%, carotin - on 20% and to obtain forage with concentration of exchange energy 9,20-9,38 mJ per 1 kg of dry matter. Silage application in combination with biological products rendered positive impact on milking efficiency of cows, the average daily milk yields in the experimental cow groups were on 1,3-1,4 kg or 6,8-7,3% higher. Application of higher quality feeds made it possible to lower the expenses of forages on 0,04 fodder units. Research results proved that the analysed preparations from sapropel could be used as an efficient conservants for silage preparations. They made it possible to raise forage quality at the minimum expenses

There was studied a preventive efficiency of complex additive Felutsen and its influences on the metabolic status of pregnant dry cows and the indicators characterizing animal yield, received from these cows. Felutsen is the carbon-vitamin-mineral additive containing a complex of carbohydrates, vitamins A, D, Е, micro-and macro elements (sodium, chlorine, calcium (Сa), phosphorus, magnesium (Mg), sulfurs, Cu, Zn, Co, Mn, selenium, iodine) in number of 300g/animal. At cows after calving metabolism disorders are caused by disorders of liver functional activity. Application of complex additive Felutsen to pregnant dry cow allows to carry out successfully preventive maintenance of metabolism disorders, including micro-and macro element metabolism. Use of Felutsen is effective preventive maintenance of pre-natal development disorders of calves, developments of oligotrophy in the postnatal period, raises safety and growth intensity of increase. The most considerable distinctions are revealed in group of cows at which the additive was applied in the form of a briquette to which there was an easy approach. In the tabular form the indicators characterizing the basic metabolic processes, an exchange of macro elements and microelements at cows are presented at application of this additive, and also body weight, disease and safety of the calves received from cows control and test groups. | Целью работы стало изучение профилактической эффективности комплексной добавки Фелуцен и её влияния на метаболический статус стельных сухостойных коров и показатели, характеризующие приплод, получаемый от этих коров. Фелуцен – это углеродно-витаминно-минеральная добавка, содержащая комплекс углеводов, витаминов А, Д, Е, микро- и макроэлементов (натрий, хлор, кальций (Сa), фосфор (Р), магний (Mg), серу, Cu, Zn, Co, Mn, селен, йод) в количестве 300 г/животное. У коров после отёла нарушения метаболизма обуславливаются нарушениями функциональной активности печени. Применение комплексной добавки Фелуцен стельным сухостойным коровам позволяет успешно проводить профилактику обменных нарушений, в том числе и обмена макро- и микроэлементов. Использование Фелуцена является эффективной профилактикой нарушений внутриутробного развития телят, развития гипотрофии в постнатальный период, повышает сохранность и интенсивность роста приплода. Наиболее значительные различия выявлены в группе коров, у которых добавка применялась в виде брикета, к которому был свободный доступ. В табличной форме представлены показатели, характеризующие основные метаболические процессы, обмен макро- и микроэлементов у коров при применении этой добавки, а также живую массу, заболеваемость и сохранность телят, полученных от коров контрольной и опытных групп.

In the research the genetic structure of populations of bulls Vitebsk of cattle breeding state farm and cows of Belarusian Black-and-White breed of Joint-Stock Company Olgovskij of Vitebsk region (Republic of Belarus) on a locus of a gene of kappa-casein was analyzed. As a result of genotyping a gene of kappa-casein by DNA-diagnostics method there were revealed three genotypes CSN3**AA, CSN3**AB, CSN3**BB. Frequency of occurrence of homozygous genotype CSN3**AA at cows has made 69,5%, at bulls of Vitebsk cattle breeding state farm - 78,3%; heterozygotic genotype CSN3**AB - 26,3% and 20,5%; homozygous genotype CSN3**BB - 4,2% and 1,2%, respectively. Frequency of CSN3**A allele in population of cows and bulls has made 0,83 and 0,88; CSN3**B - 0,17 and 0,11%, respectively. The presence of authentic influence of polymorphic variants of a gene of kappa-casein on level of milk yield and fat and protein content in cow milk was stated. The highest milk productivity in course of 305 days of lactation was observed at cows with homozygous genotype CSN3**BB (5984 kg), that was on 890 kg higher than in animals with genotype CSN3**AB (5094 kg), and on 1406 kg higher (Р less than 0,05), than at animals with CSN3**AA genotype (4578 kg). Cows with B kappa-casein allele in genome were characterized by higher fat content in milk (CSN3**AB - 3,61%, CSN3**BB - 3,72%) than animals with a CSN3**AA genotype - 3,60%. Cows with genotype CSN3**BB had higher level of protein in milk (3,28%) in comparison with the animals with CSN3**AA genotype (3,18%). In animals with CSN3**AB genotype the mentioned above index 3,19%. Research results showed that genetic variants of the gene of kappa-casein are important for selection practice as they could be used as breeding-genetic markers which could raise milk yields and protein content in milk

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.

The influence of iron deficiency state on metabolic processes and intensity of lipids peroxidation processes at dawn-calving cows was analysed in the conditions of the Republic of Belarus. In course of study there was determined the intensity of lipids peroxidation processes in blood plasm depending on the level of hemoglobin and red blood corpuscle quantity. It was studied that in animals with low hemoglobin the oxidizing stress proceeded more actively than in animals with the normal hemoglobin level. Data analysis of lipids peroxidation processes showed that pregnancy condition was accompanied by strengthening of mentioned above processes. That fact was proved by the indicators of lipids peroxide oxidations presented both in absolute and in relative units. The content of diene conjugates, containing in 1 mg of lipids, was in 1,3-1,8 times higher at pregnant cows in comparison with non-pregnant ones, trieneketones content - in 1,2-1,6 times. Similar differences were observed in the process of analysis of diene conjugates and trieneketones values rated per 1 ml of plasma. More considerable differences were stated for trieneketones; the analysed indicator was in 1,6-2,1 times higher at pregnant cows

The nonspecific resistance of cows at the interlactation period was studied for the forecasting of the postnatal period progress in the conditions of the Republic of Belarus. Influence of the complex preparations Erimetrinis and Richometrinum on restoration of cow reproductive function was investigated. It was established, that the developed new complex preparation Erimetrinis possessed the uterotonic, antiphlogistic, pathogenetic and stimulating action. Evaluation of the presented preparation was tested have under production conditions and confirmed its high efficiency. After application of Erimetrinis there was noted a fast restoration of both endometrias histostructure, indices of cellular protection, and cow clinical characteristic. Microflora which was discharge from cow uterus content, which were sick with postnatal purulo-catarrhal endometritis, was sensitive and high-sensitivity Erimetrinis and had a zone of growth inhibition from 19,6 up to 36,1 mm, while after Richometrinum application it was sensitive except for staphylococcus and diplococcus in which the growth inhibition zone was from 15,1 up to 15,4 mm. Study of indicators of bactericidal activity of cow blood serum in course of treatment with the Erimetrinis it was established, that starting from the fourth day of the treatment the analysed indicator increased up to 56%, and by the moment of the clinical recovery it was 82,4+/-2,16%. Indicators of lysozymic activity of blood serum at the moment of cow recovery were 13,4+/-1,35 mmol/l. Essential changes were marked in the phagocytic activity of leukocytes, phagocytic numbers and phagocytic index. Cows which were subjected to treatment with Richometrinum all mentioned above indicators were increasing starting from the tenth day of treatment beginning, and clinical recovery was stated on 7,4 days later than after Erimetrinis application

In the conditions of biogeochemical zone of the Republic of Belarus the most important role in mineral metabolism is played by such major mineral elements as calcium, magnesium, phosphorus, potassium and trace elements - cobalt, cupper, iron, iodine, zinc, manganese, and selenium. Based on the above there was determined the interrelation between the content of these minerals in fodder and blood of milking and dry pregnant cows. As a result of realized study it was found out that the content of major mineral elements and trace elements in fodder did not always correspond to their level in blood. In the conditions of insufficient supply of Ca, F, Mg, K, Fe, Си and Co in cow diets, the level of potassium in blood was lower standard and the other analysed minerals were within the standard limits. There was stated the direct correlation relationship between the level of some biochemical indices and content of mineral substances in cow diets. Positive correlation was stated between the content of calcium and magnesium and cholesterin level in blood

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%