Abstract
Enzyme immunoassay, being a more sensitive method, makes it possible to identify specific antibodies in samples of combined milk. The ELISA study of harvested milk in farms can become an important element in the system of anti-brucellosis measures regarding the control of the epizootic state in farms taking into account the availability and ease of implementation of this method. For screening express-diagnostics of bovine brucellosis the method of enzyme immunoassay with milk of cows has been developed. ELISA with milk serum is specific, sensitive, easy to formulate, account for and interpret the results. It has been found that the conditions of storage and transportation of milk samples corresponding to room temperature values and leading to fermentation do not affect the level of specific anti-viral immunoglobulins for eight days, and the question of the use of a cold chain during transportation of milk samples to be examined to the place of analysis can be withdrawn from the agenda. When working out the optimal sample preparation, the difference in the specific signal when setting the ELISA between the milk serum obtained by high-speed centrifugation and the milk serum obtained by fermentation for 24 hours was less than 10%. Therefore, high-speed centrifugation was chosen for the preparation of milk serum samples during the ELISA study. The possibilities of using ELISA with milk serum on vaccinated and non-vaccinated cattle against brucellosis have been studied. Milk and blood for testing in the ELISA should be taken 6 months or more after vaccination (within the instructional time frame). A high level of correlation was established between ELISA data with milk and ELISA data with blood serum, regardless of epizootic or immune status (satisfactory and unfavorable herds, vaccinated and unvaccinated animals), which amounted to 86.8–92.0%.