The daily requirement for calcium and phosphorus by giraffes to sustain the growth and maintenance of their skeletons is large. The source of sufficient calcium is browse. The source of necessary phosphorus is obscure, but it could be osteophagia, a frequently observed behaviour in giraffes. We have assessed whether bone ingested as a result of osteophagia can be digested in the rumen. Bone samples from cancellous (cervical vertebrae) and dense bones (metacarpal shaft) were immersed in the rumens of five sheep, for a period of up to 30 days, and the effect compared to immersion in distilled water and in artificial saliva for 30 days. Distilled water had no effect on the bones. Dense bone samples were softened by exposure to the saliva and rumen fluid, but did not lose either calcium or phosphorus. In saliva and rumen fluid the cancellous bone samples also softened, and their mass and volume decreased as a result of exposure to saliva, but in neither fluid did they lose significant amounts of calcium and phosphorus. We conclude that although saliva and rumen fluid can soften ingested bones, there is an insignificant digestion of bones in the rumen.

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

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