Hypophosphatemia was induced in 2 cows by reducing phosphorus content in their feed after parturition. Serum inorganic phosphorus (Pi) values decreased to 1 mg/dl within 10 days after parturition; and RBC adenosine 5'-triphosphate (ATP) and reduced glutathione values decreased to 50 and 70% of baseline values, respectively. Methemoglobin concentration was moderately higher than normal. These changes preceded the onset of hemolysis, and anemia progressed with decreases in PCV, hemoglobin concentration, and RBC counts. Serum Pi resumed its normal value when anemia was most severe. This RBC disorder was confirmed to be characteristic of hemolytic anemia in cows resulting from hypophosphatemia. The RBC glycolytic intermediates, totaal trisoe phosphate (combined glyceraldehyde-3-phosphate and dihydroxyacetone phosphate content) and fructose-1, 6-diphosphate, greatly increased in vivo and in vitro with decreases in serum or plasma Pi and RBC ATP. From our results, we concluded that inadequate Pi in the plasma impairs the function and viability of RBC by hindering the production of ATP via disturbance of reactions at the glyceraldehyde-3-phosphate dehydrogenase step.

In our previous study, it was demonstrated that the administration of anion salts, which slightly lower the dietary cation-anion difference (DCAD), in the prepartum period is safe and effective for preventing milk fever in multiparous cows. In the present study, several clinico-pathological constituents in serum and urine, which might be related to milk fever, were analyzed using stored samples from the previous study to identify clinico-pathological parameters for easily evaluating the efficacy of lowering DCAD and to further investigate the mechanism by which lowering DCAD prevents milk fever. Among the parameters analyzed in the present study, inorganic phosphorus (iP) was involved in milk fever because the serum concentration and urinary excretion of iP were significantly higher in the group of primiparous cows (heifer group), which did not develop hypocalcemia, than those in other groups of multiparous cows. Serum chloride concentrations in the heifer group and the group of multiparous cows fed anion salts (anion group) tended to remain higher than those in other control groups of multiparous cows suggesting that serum chloride concentration may be utilized for evaluating the status of metabolic acidosis and the efficacy of lowerng DCAD in dairy cows fed anion salts. In addition, plasma estradiol-17beta concentration in the heifer group tended to be lower at parturition compared with that in other multiparous groups suggesting that estrogen known as a potent inhibitor of bone resorption may be involved in developing milk fever.

The comparative analysis of application of cereal ensilage produced with addition of microbial and enzymatic preserving agents Axphast Gold and Biotrof on fodder digestibility, hematological indexes and cicatrical digestion of cattle rearers was realized in the conditions of the Republic of Belarus. Cattle feeding with the analysed silage rendered positive effect on digestibility of the forage dry matter, which was on 2% higher the control index, organic matter - on 2,4%, nitrogen-free extractive substances - on 2,84%, fat - on 0,58%, protein - on 2,3%, cellulose - on 2,1%. Use in feeding of ensilaged forages from the cereal perennial grasses preserved by the microbial- enzymatic preparation produced by company Biota rendered the positive influence on use of nitrogen, calcium and phosphorus. There was also noted the increasing of the content of volatile fatty acids in paunch of young cattle silage fed with Axphast Gold that testified of more effective utilization of forage

Activity of amylolytic, proteolytic, and lipolytic enzymes in the content and mucosa of intestinal tract, alkaline phosphatase in mucosa of intestinal tract, as well as the determination of calcium and phosphorous concentration in gastro-intestinal tract of hens were analyzed in the conditions of the Republic of Belarus. Results of analysis of the obtained experiment results of laying hens of parental stock by influence of various vitamin-mineral additives were presented. The highest activity of amylolytic, proteolytic, and lipolytic enzymes in 170-330 days old laying hens of Belarus-9 cross was marked in small intestine. There was stated the decreasing of enzymatic activity in proportion to removal from a stomach. At the same time, activity of alkaline phosphatase decreasds. Activity of alkaline phosphatase, proteolytic and starch-reducing enzymes in a mucous membrane of a duodenal gut was a bit higher than in mucosae of jejunal. Lipolytic enzymes showed high degree activity in mucosae of jejunal. Enzymic activity in large bowel was low. Addition of iodine-containing preparation Kajod into hen layer diets increased the activity of alkaline phosphatase, of amylolytic, proteolytic, and lipolytic enzymes in intestines. Enzymic activity of mucous intestines at hens of breed Plimutrok in process of removal from stomach decreased. In course of the period from 240 to 330-days old age the activity of studied enzymes in hen intestines decreased. Replacement of mineral additive Cockleshell by Pikumin did not render negative influences on changes in digestive enzyme activity. In 170-days old laying hens of Belarus-9 crossbreed the calcium content increased from the stomach to the small intestine, and then decreased in thick department. In the 200-days old hens the calcium concentration in a stomach increased in both groups and gradually decreased in the department of small intestine, but in rectum its quantity increased in both groups. In the period of intensive egg-laying (280 days) the general calcium content in thin department of intestines was less than in the stomach, later it increased in cecum and decreased in rectum. By the end of the experiment (330 days) the concentration of calcium in control group decreased from the stomach to the beginning of thick department of intestines, but in rectum its quantity increased. In experimental group the calcium content increased from a stomach to cecums and then decreased in rectum. In distribution of inorganic phosphorus in gastrointestinal tract departments at hens of various age groups the tendency to increase in its quantity in small intestine and the beginning of thick department of intestines, and then to reduction in rectum was observed. And at hens receiving premix Ajdeko, the phosphorus content, since 200-day age, was higher, than at hens receiving the basic ration