In the conditions of the Republic of Belarus there was studied the preventive efficiency of various forms of a complex additive Felutsen against polymicroelementoses of calf-bearing dry cows and its influence on some of biochemical blood indexes. Research results proved high prophylactic efficacy of various forms of the additive Felutsen against polyhypomicroelementoses of calf-bearing dry cows. Restoration of a microelement homeostasis of cows made it possible to normalize the functional activity of liver, to prevent development renal insufficiency and dystrophic changes in bone tissue. The most expressed metabolic changes in blood of calf-bearing dry cows were stated after application of the carbohydrate-mineral additive Felutsen-briquette universal. There was given the analysis of structure of studied forms of complex additive Felutsen; indexes of trace element metabolism in cows; indexes of protein metabolism and level of nonprotein nitrogen; indexes of blood characterizing the functional condition of liver and carbohydrate metabolism of cows; indexes of trace element metabolism in cows after the termination of application of the additive.

In the conditions of the Republic of Belarus there were studied the biochemical changes in blood of cows with chronic dystrophic processes in liver by an example of fatty hepatodystrophy. There was given an estimation of these changes taking into account animal physiological state (pregnancy). The metabolic profile including the enzymatic block from aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, cholinesterase, serum albumin, total cholesterin, total bilirubin and thymol test can be used in clinical and biochemical diagnostics in case of hepatic steatosis. Its changes in case of hepatic steatosis were characteriszed by increase in activity of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, decrease in activity of cholinesterase, decrease in blood serum of albumins concentration, increase in general cholesterol and high values of thymol tests. Determination of gamma-glutamyl transpeptidase influence and flocculation test on apo-beta-lipoproteins showed that they should not be included in this complex due to their small information content. In the process of estimation of changes of a metabolic profile of blood serum it wasnecessary to consider the physiological state of animals (pregnancy) because the activity of some enzymes and metabolite concentration at them could essentially differ. Taking into consideration the character of hepatic steatosis course, the studied metabolic profile can be recommended for hyposthenic current chronic activity with the considerable involvement degree of hepatocytes into the process.

In the conditions of the Republic of Belarus there was studied the activity of alaninaminotranspherase (AIT) and aspartate aminotransferases (AsT), alkaline phosphatase, lactic dehydrogenase, cholinesterase, alpha amylase in blood serum, liver and pancreas of 130-158-day old replacement chicks vaccinated against Newcastle disease. Research results showed that the most essential changes were observed from such enzymes, as AsT and AIT. Increasing of AIT activity in a liver, pancreas and blood serum of immunized hens was stated on the seventh day after vaccine administration. Character of changes can testify both the increasing of synthesis of the mentioned enzymes, and also their posttransmitting activation which took place due to intensification of transamination processes. Changes of activity of alkaline phosphatase, cholinesterase and alpha amylase were the most expressed on the 14th and 21st days of research. It was possible to assume, that there was a stimulation of synthetic function of hepatocytes under the influence of the vaccine. It was possibly the decreasing of enzymatic functions pancreas.