The scarcity of green during summer months imposes nutritional stress on farm animals. In this study we examined the effect of nutritional stress on various biochemical parameters of rabbits.Control and green deprived groups each of 20, weaned New Zealand White rabbits, of either sex, were randomly placed and observed for two months. Then green was re-introduced in deprived group for again two months. Blood sera harvested at every 15th day and analyzed using RA 50 Chemistry auto analyzer. Significant (p0.05) decrease of alkaline phosphatase (AKP), lactate dehydrogenase (LDH) and increase in gamma glutamyl transpeptidase (GGT) and serum cholesterol was observed in rabbits green deprived group.

The protective effects of high levels of dietary iron, copper, zinc or protein on lead toxicity were studied in chicks. Growth retardation, reduction of feed intake, anemia and accumulation of lead in the bone and kidney were observed in chicks fed a diet containing 500mg lead as chloride/kg of feed for 42 days. Early changes due to ingested lead were inhibition of red blood cell 8-aminolevulinic acid dehydrase at all doses and no effect of iron, copper, zinc or protein addition were observed

In the conditions of the Republic of Belarus there were determined the doses of application of siliceous sapropel as well as there were studied the indexes of ruminal digestion and digestibility of diet nutrient substances by bull calves. The studied siliceous sapropel of the lake Pribylovichi (Belarus) occurence on 42% consisted of organic substances and on 58% - of mineral substances: calcium, phosphorus, magnesium, potassium, sodium, iron, zinc, manganese, and copper. The studied sample of sapropel did not render toxic action on test objects of infusorian Tetrahymena pyriformis in the conditions of its addition into the basic forage in number of 1%; 3%; 5%; and 10%. However, its higher concentrations (10%) retarded the development of Protozoa. Feed additives with the content of siliceous sapropel in mixed fodder in dose of 1%, 3% and 5% increased the relative biological value of forage in the experiments on test objects of infusorians Tetrahymena pyriformis in the average respectively on 5,4%, 5,0 and 2,6%. Higher concentrations of sapropel in mixed fodder (5 and 10%) lowered its nutritional value. Inclusion of siliceous sapropel in bull calve rations activated the enzymatic processes in farding bag and increased the digestibility nutritive elements on 2,3-3,6% except for protein, digestibility which was practically at identical level at animals of all groups.

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

In the conditions of the Republic of Belarus there were analyzed the efficiency of 13-18-month old young stock of cattle bred for meat in the conditions of various energy value nutrition levels with the determination of nutrients intake of a diet. It was established that use of rations with various level of metabolic energy and protein breakage rendered the positive influence on nutrient digestibility of rations. This made it possible to improve the digestibility of dry and organic substances, nitrogen-free extractive substances and fibre at the bull calves which were fed with 63% of cleavable protein, as well as to increase the metabolic energy up to 10% in the ration, surpassing the control indexes respectively on 3.1; 2.5; 2.8; and 2.9 items. Adjournment from the acquired nitrogen considerably increased and made up to 64-70%. Productivity of fattening young cattle stock made it possible to obtain 977.7-1011.0 gram of live weight gain. As a result, the growth energy was stated at the level of 15,90-17,33 МJ in the conditions of conversion of metabolic energy into growth of 13,81-14,26% and expenses of metabolic energy of the ration per 1 MJ in live weight gain of 4,72-5,46 MJ.

Analysis of the optimal scheme of doses and rates of combined administration of probiotic Dialakt and immunostimulant Alveozan was realized in the conditions of the Republic of Belarus by the example of 1500 broiler chickens of cross Kobb- 500. Chickens of the first (controlled) group were given only total ration, balanced with the main nutrients. For the chickens of the second group were administrated with immunostimulant Alveozan with water starting from one day old age, every day in dose of 10 mkg/kg of body weight once a day in course of 5 days successively and with 7 days interval till the end of growing period; and probiotic Dialakt was administrated with water in dose of 0,1-0,2 ml/head (10,0-20,0 mln microbial bodies) starting from one day old age, once a day in course of 5 days successively and with 6 and 14 days intervals till the end of growing period. Chickens of the third group were administrated Alveozan in dose of 10 mkg/kg of body weight with drinking water once a day in course of 5 days with 10 days interval till the end of growing period; and Dialakt in dose of 0,1-0,2 ml/head with drinking water starting from one day old age, every day in course of 5 days with 6 and 14 days interval till the end of growing period. The research results showed the following optimal regime of complex application of the analyzed preparations: immunostimulant Dialakt - in dose of 0,1-0,2 ml/head with drinking water starting from one day old age, once a day in course of 3 days successively with 6 and 14 days intervals till the end of growing period; and immunostimulant Alveozan - in doze of 10 mkg/kg of body weight with drinking water once a day in course of 5 days with 10 days interval till the end of growing period. Complex application of Dialakt and Alveozan promoted the increasing of organometric indexes, specific volume and size of thymus in 1,5-1,8 times (P less than 0,01), Fabritsiya bursa - in 2 times (P less than 0,01) and lien - on 11,1% (P less than 0,05)

The research in RUP Scientific and Practical Center of Animal Breeding of National Academy of Sciences on such parameters as consumption of forages, processes of rumen digestion, morphological and biochemical structure of blood has shown that usage of wet grain preserved with Kormoplus for young cattle fattening has a positive effect on physiological condition and digestibility of nutrients and promotes nitrogen usage by animals that increases at 7,0 and 1,6%

Determination of the efficiency of young fat stock feeding with wet rolled maize grain which was preserved by means of different preparations was realized in the conditions of the Republic of Belarus. The following preserving agents were applied: HV-2 (by- product of amino-formaldehyde resin); AIV 3 Plus (mixture of 62% formic acid and 24% ammonium formate; KEMIRA, Finland); carbamide (30 kg/t) with 40 g/t of complex mineral supplement. Feeding of young fat stock with rolled maize grains preserved by NV-2 promoted the increasing of nutrient digestibility on 1,5-5,0%, nitrogen use - on 2% in comparison with control. Application of rolled maize grain preserved with AIV-3Plus and carbamide with the complex mineral supplement made it possible to increase the digestibility of nutrients on 1,0-4,8% and nitrogen use - on 1,6-1,7%. Introduction of rolled maize grain preserved with NV-2 into rations of bull calves increased their productivity on 4,7% (P less than 0,05) with the simultaneous lowering of forage expenses on 1,9%. Application rolled maize grains preserved with AIV-3Plus made it possible to increase daily average weight gain on 3,8% and lower the forages expenses on 2,6%. Use preserved with NV-2 and AIV-3Plus rolled maize grains in rations of young fat stock lowered the production cost price on 11,9% and 10,8% that proved the efficiency of the studied fodder