The activity of plant and microbic phytases depending on the medium pH was studied. The factors have been investigated as follows: decomposition efficiency of seed ingredients and the releasing of phytate phosphorus; the efficiency of the adsorption of phosphorus under the in situation of microbic phytase; the influence of microbic phytase feeding in the ratios with low content of accessible phosphorus for assimilation of phytate phosphorus and poultry production indices. It has been stated that the microbic phytase has a wider optimum of action depending on pH value. The microbic phytase positive action on the metabolism of phosphorus in the chicken organism has been determined through the experimental investigations.
The experiments on pure-strain laying hens of meat direction showed that the mineral supplement consisting of sodium metasilicate, sodium sulfate, sodium bicarbonate and sodium selenite added to the standard feed of PK-1-26 composition improved the biological value of incubation eggs as a results of the increased quantity of glycogen, RNA, total lipids and carotenoids. This promotes and increase in hatchability of chicken by 0.45%.