Subclinical mastitis prevention in dairy cows necessitates the use of effective pre-and post-milking udder preparations. Many imported post-milking udder treatments have proven ineffective and costly, prompting the exploration of composite preparations based on chemical compounds. This study aims to assess the bactericidal properties of Promixan, a preparation based on Anavidin and its impact on subclinical mastitis prevention and milk quality under production conditions. The experimental study took place at two Republic of Kazakhstan farms. Three groups of cows, comprising those with subclinical mastitis (for disease treatment) and healthy cows (for disease prevention), were selected. To evaluate the bactericidal efficacy of post-milking udder treatments, microbial concentration dynamics were observed every two hours until the subsequent milking. Promixan exhibited 98.1 and 96.7% effectiveness in preventing subclinical mastitis in healthy cows at the Adal Agro-Industrial Complex farm and E.S. Aidarbayev farm, respectively, after 4 hours of exposure. In the group of sick cows, it demonstrated effectiveness rates of 95.3 and 94.3%, respectively. These results indicate that Promixan matches or surpasses the bactericidal properties of analogs. When used on sick cows, Promixan outperformed Blockade and Vet Clean I-Film by 2.1 and 2.2%, respectively, indicating its comparable effectiveness. Experimental studies revealed that Promixan's bactericidal properties surpassed those of Blockade and Vet Clean I-Film by 3.4 and 3.3%, respectively. Promixan effectively forms a bacteriological protective film on cow udder teats, preventing microbial penetration into the skin, and proves to be a viable alternative to existing treatments for subclinical mastitis prevention in dairy cows under production conditions.