Mogutova V. Sanitary and hygienic assessment of milk disinfection method by nanoparticles of silver.

The thesis presents the data on the sanitary and hygienic assessment of the cowsheds on the 6 farms of Sumy region on the basis of microclimate parameter determination. The cowsheds were divided into 2 groups - the ones that meet the requirements of VNTP-AIC-01.05 "Animal breeding enterprises (complexes, farms, private farms)" by milk production conditions (group 1) and the cowsheds that less meet the above requirements (group 2). It has been stated that the relative quantity of milk that is not suitable for consumption by people (MNSР) but that is produced on the farms alongside with milk of high-quality, depends on the sanitary and hygienic conditions of its production. On the farms of group 1 in the summer - autumn and spring-winter periods it comprises 5,07 and 7,57 %, on the farms of group 2 - 11,0 and 14,65 % respectively. By their physical and chemical properties MNSР produced on the farms of group 1 had lower indices of acidity, higher indices of total part of fat and protein, total part of dry milk as compared with group 2. Such milk can be used in calf feeding. In the milk (MNSР) of group 1 the highest content had samples with Staphylococcus aureus - 41,7 %, Streptococcus agalactiae - 40,0 %, in the milk of group 2 - Staphylococcus aureus - 46,7 %, Streptococcus agalactiae and the associations of conditionally pathogenic microorganisms - 18,3 %. It has been determined that antimicrobial action of nanoparticles of silver (NS) to conditionally pathogenic microflora of MNSР depends on the concentration of the preparation and the period of exposition. The lowest antimicrobial effect was detected when one drop (0,06 sm3) of colloid solution of silver nanoparticles was added to 1 liter of milk, the exposition period was 2 minutes. The highest effect that helps to kill the microorganisms was achieved when 6 drops (0,36 sm3) of the preparation were added and the period of exposition was 30 minutes. When MNSР having nanoparticles of silver was fed to the calves the average weight gains of the calves increased at 14,99 % for 30 days, the amount of erythrocytes and hemoglobin - at 14,7 and 4,29 %, the amount of leucocytes reduced at 8,78 %.