At the first stage of the dissertation research, the efficiency of egg production was determined by keeping 3 groups of laying hens in cages of 5-6-tier batteries of classic designs of various manufacturers, namely LLC "TEHNA" (Ukraine), "Big Dutchman" and "Salmet" (Germany). A significantly higher (p<0.001) egg-laying rate per initial laying hen was found in the hens of group 3 (251.4 eggs/hen), which were kept in cage batteries of the "Salmet" company, and it was lower by 8.1 % in group 2 ("Big Dutchman"). The coefficient of efficiency of egg production for keeping hens in the cage batteries of the company "Salmet" (3 gr.) was 22.5 c. u. and was significantly higher (p<0.001) than in the batteries of the company "Big Dutchman" (group 2) and LLC "TECHNA" (group 1) by 3.1-16.0%. In the second experiment, the efficiency of egg production was determined by keeping hens in classical cage batteries of the "Salmet" company of two modifications. Keeping hens in 12-tier cage batteries ensured the production of 30.4 thousand eggs per 1 m^2 of the poultry house area, namely 1.7 times more than in 6-tier cages at a significantly higher (by 3.4 %) level of the coefficient efficiency of their production. The third experiment was conducted to determine the possible consequences of replacing traditional 3-layer batteries with 6-12-layer ones. The main result of this research is the discovery of the fact that increasing the height of laying hens in cage batteries from 1-3 to 4-12 tiers does not lead to a decrease in their laying capacity, preservation and level of egg production efficiency. In the following, 4th, 5th, and 6th experiments, the laying capacity and other economically useful characteristics of hens were determined depending on the stocking density of their placement in cages of 12-tier classical batteries of the company "Salmet". The slight overcrowding of hens of the 2nd group at the beginning of the productive period to 26.0 hens/m^2, as well as the third group to 28.0 hens/m^2, led to a decrease in their laying capacity, preservation, and the level of the efficiency coefficient of egg production from 19.7 c. u. to 19.1-19.2 c. u. (by 2.6-3.1 %). Overcrowding of hens to 27 hens/m^2 led to a decrease in their laying capacity by 4.0 % (to 239.8 eggs/hen) and a decrease in survival by 8.8 % (to 85.4 %). Planting chickens in cages at a stocking density of 14 hens/m^2 ensures their slightly higher egg-laying rate (by 0.8 %) and survival (by 3.3 %) than at a stocking density of 25 hens/m^2 . However, at the same time, the efficiency of the use of production areas is significantly reduced due to the production of 1.8 times less eggs, namely from 85.2 million eggs. up to 47.6 million eggs in a poultry house with an area of 2640 m^2 for 43 weeks of the productive period. The cost of egg production for boarded hens in cages at a stocking density of 25 hens/m^2 was UAH 1.27/eggs in prices as of January 1, 2022, the profitability of their production is 68.6 %, and at a stocking density of 14 hens/m^2 – UAH 1.28/eggs and 68.7 %. Therefore, from the point of view of the cost and profitability of the production of food eggs, no advantages were found for placing hens in cages of 12-tier batteries of classic designs with optimized stocking density. Significant advantages relate to 1.8 times increase in the production of food eggs with lower resource costs, including per 1 m^2 of poultry house area. It has been proven that the stocking density of laying hens of egg crosses in cages of 12-tier batteries of classic designs should be 25 hens/m^2 (400 cm^2/hen). Boarded laying hens at a density of 14 hens/m^2 in accordance with the requirements of the EU Directive 99/74 of July 19, 1999, although it contributes to a slight increase in their laying capacity and preservation, but leads to a significant decrease in the efficiency of the use of available production areas. It was found that when hens are kept at a stocking density of 25 hens/m^2, the morphological indicators of their blood, 8 biochemical indicators of their serum, as well as the activity of 5 investigated enzymes correspond to the reference values. An increase in the density of laying hens to 27 eggs/m^2 leads to an increase in the content of leukocytes in the blood, the content of glucose and the activity of AST and LDH in the blood serum. It is recommended that enterprises engaged in the production of food eggs for keeping egg-cross hens in cage batteries of classic designs, for the reconstruction of poultry houses, replace the traditional 3-4-tier batteries with the latest 12-tier ones with laying hens in them at a stocking density of 25 hens/m^2, which will ensure an increase in the volume of eggs obtained by at least three times without the construction of new premises and without the expenditure of energy resources for heating the poultry in the cold season.
