Introduction. Interest in dairy goat breeding, as an integral and important part of the livestock industry, has been growing steadily in recent years. At the same time, the dairy productivity of goats is largely determined by the balance and usefulness of the diet. Materials and methods. The goat-breeding farm of the Lukoz agroholding in the Sernursky district of the Republic of Mari El was chosen as the basis for the experimental study, where dairy goats at the stage of second lactation were selected according to the principle of analogues, which were divided into 3 groups of 20 heads each. The control group was kept on a regular diet. Goats belonging to the experimental groups received chlorella suspension daily with water at the rate of 40 ml per animal. The second experimental group additionally received a probiotic Bacillus subtilis at the rate of 10 g per animal. Every 10 days, milk productivity was analyzed by control milking and blood and milk samples were taken for laboratory analysis. Results and discussion. The results of the study showed a significant increase in the number of erythrocytes and hemoglobin in the blood of experimental groups of animals. In addition, there was an increase in the concentration of glucose, total protein, albumins and globulins in the blood serum, which indicates the activation of metabolic processes, including carbohydrate metabolism. The addition of chlorella suspension to the diet of animals has a beneficial effect on the functioning of the body’s immune system. Conclusion. The use of chlorella suspension in goat feeding diets helps strengthen the immune system and increase animal milk yields, and also increases the content of total protein, casein, fat and minerals in milk. This is an important factor for dairy producers, as it allows them to increase the quality and value of the resulting product.