In the conditions of the Republic of Belarus there was studied the interrelation between content of major nutrient elements (calcium and phosphorous) and trace elements (iron, copper, cobalt, and manganese) in forages and blood of first-calf cows at the first and last stages of lactation. Also, there were developed formulas of mixed forages and a premix for these animals. The studies were realized at the Agricultural Production Co-operative Olgovskoe of Vitebsk region (Belarus). Research of analysis of forages and state of mineral metabolismat heifers made it possible to draw following conclusions: in cow rations there was marked the deficiency of vitamin D, as well as some trace elements (cobalt and manganese) in the conditions of calcium and phosphorus excess. In spite of a high content in a calcium in diets, it was noted than in blood plasma the concentration of this element was below the standard for the majority of animals. Lack of cobalt and manganese of whole blood of cows was connected with a low level of these elements in cow diets. The surplus contents of copper in forages and blood of animals against the background low activity of ceruloplasmin the weakened antioxidant defense of heifer cows. For preventive treatment of possible hypo trace element deficiencies and metabolic disorders of heifer cows at the final stage of lactation there can be recommended the correcting of cow diets with inclusion into their composition of the developed for compound of mixed fodder and premix.

In the conditions of the Republic of Belarus there was analyzed the influence of the following paratypical factors on cow productive longevity: age of the first calving; milk yield at the first lactation; and a birth season. At the experimental animals there studied the indices of dairy efficiency: a lifelong milk yield (kg); a lifelong yield of dairy fat (kg); the total duration of the lactation period (days); duration of practical use (lactations). There was noted a tendency of increasing of a term of productive use and lifelong productive efficiency at the animals the practical economic use of which was begun in later terms. The insemination of these animals was approximately realized at the age older than 21 months. Also it was stated that in accordance with all investigated indices (except for a milk yield per one day of lactation) the highest indexes were typical for cows which had the least milk yield at the first lactation.

In the conditions of the Republic of Belarus there was analyzed the efficiency of administration of nonconventional feed materials in diets of highly productive cows and its influence of indexes of natural resistance at different physiological stages of animals. In the process of studying of adaptation processes of highly productive cows at different stages of lactation it was determined that feeding with nonconventional melanoidin-humic additives at different physiological periods rendered a positive influence of highly productive cows, promoted the increasing of natural resistance of animals and improvement of immuno-humoral blood indexes. Administration of an additive Ehkolin in a ration of highly productive cows with stimulation for increasing milk flow in a dose of 100 ml per head promoted the increasing of blood serum bactericidal activity on 5,2%, beta-lysine activity - on 7,2%. Feeding of animals at a basic lactation period with 50 ml of preparation Ehkolin-2 provided the maximum increasing of lysozyme activity of blood serum (on 6,2%) and beta-lysine activity of blood serum (on 12,7%), and also promoted the activation of leukocytopoiesis. Addition of Ehkolin-3 in ration structure of dry cows in a dose of 750 ml increased the indexes of lysozyme activity of blood serum on 7-8,6%, bactericidal activity of blood serum - on 2,2-3,6% and beta-lysine activity of blood serum - on 2,2-3,6%.

In the conditions of the Republic of Belarus annually in 25-50% of total number cattle there was stated ketosis (milk fever); as a result, from each cow in cattle breeding farms receive less milk per lactation on 10-15%, as well as there is a lowering of fat and protein (and biological value) content in milk. In course of the study there was analyzed the influence of mineral and energy supplement Felutsen K-1-2 for the preventive treatment of ketosis of highly productive cows. Research results showed that application of the analyzed additive rendered the positive influence on morphological and biochemical blood indexes. In particular, there was an increasing of hemoglobin level, content of total protein, albumins, magnesium, calcium, and phosphorous. It also rendered positive influence on lipid exchange. In course of the study it was marked, that the prophylactic efficacy of mineral and energy supplement Felutsen K-1-2 in the experimental groups was 100%, and the control one – 80%.

In the conditions of the Republic of Belarus the seasonal derangements of metabolic processes at high-producing cows usually take place in the period from March till May. Analysis of efficiency of application of national preparation CMP (complex-mineral preparation -iron (15 mg/ml); iodine (6,8 mg/ml); magnesium (6,0 mg/ml); selenium (0,32 mg/ml) and vitamin preparation Trivitim (vitamin A – 30000 IU; , vitamin D – 40000 IU; vitamin E – 20 mg) for the preserving of high milking yielding capacity and prevention of metabolic processes disorders was realized. Four groups of high productive cows were formed. First group was entered 10 ml of CMP intramuscular; cows of the second group were entered 10 ml of Trivitim intramuscular; cows of the third group were entered CMP and Trivitim in the same doses; and the fourth group was a controlled one. On the 1-st, 7-th and 15-th days there was realized evaluation animal clinical state, hematologic and biochemical blood indexes (leukocytes; erythrocytes; hemoglobin; thrombocytes; ESR; total protein; albumins; urea; creatinine; glucose; calcium; phosphorous; magnesium; iron), and average daily milk yield. There was also analyzed the phagocytic activity of neutrophilic leukocytes. Research results showed that content of leukocytes and ESR in blood in all experimental groups was within the standard limits. In the first experimental group there was state the increasing of hemoglobin (from 91,4 +/- 4,38 up to 111,83 +/- 4,3 g/l (P less than0,05) ) and erythrocytes (from 4,48 +/- 0,21 up to 5,97 +/- 0,45 10E12/l) content. The same changes were stated in cows of the 2-d and 3-d experimental groups. Content of hemoglobin and erythrocyte in blood of cows which were administrated with CMP and Trivitim increased from 90,6 +/- 0,06 to 99,83 +/- 3,61 g/l and from 4,51 +/- 0,27 to 5,55 +/- 0,28 10E12/l, respectively. Analyze of biochemical indexes of cow blood showed that content of total protein, calcium, phosphorus, magnesium and iron increased. On the 15-th day there was stated the decrease of urea. Research results proved that the combined application of CMP and Trivitim was efficient and prevented subclinical disorders of metabolic processes

Analysis of synchronization of oestrus of cows by means of Ovsynch and Pre-Synch methods was realized in the conditions of the Republic of Belarus. Research results showed that estrus synchronization by means of Pre-Synch method proved to be more efficient by means of higher percentage of fertilization after the first and second insemination in comparison with Ovsynch method. Treatment of cows with the substances Surfagon and Tetravit for synchronization of oestrus did not render negative effect on milk quality and safety.

Development of a new national preparation for the preventive maintenance of cow mastitis, fissures of milking tubes skin of cow udder was realized in the conditions of the Republic of Belarus. The preparation Maz' Solnechnaya ("Unguent Solnechnaya") did not contain antibiotics, hormones and other synthetic components. Natural components of a preparation provide long anti-inflammatory action, stimulate local blood circulation, regeneration of epidermis and accelerate processes of healing of microtraumas. Besides it possesses high efficiency at preventive maintenance of mastitises at cows.

Using macro and microelements, vitamins A and D in correspondence with norms of Institute of Animal Husbandry (1992) per 1 kg of dry substance of a diet: phosphorus - 5,29 g, calcium - 7,46, sodium - 5,59 g, copper - 12,64 mg, zinc - 77,26, magnesium - 77,26, vitamins A and D correspondingly - 23,74 and 1,02 thousand ME for highly productive lactating cows with average daily milk yield of 32 kg at summer feeding compared to Agricultural Academy norms (1985) promotes increase of the so called relative products outcome and profit from basic fatness (3,4%) milk sale per 1 animal at 411 rubles

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