Background and Aim: Dairy cattle breeding plays a significant role in providing the population with high-quality, reasonably priced goods. The development of this industry and its effectiveness depends on the proper use of available feed products. Feed additives (FAs), as a rule, should compensate for missing elements in the diet. This study aimed to determine the effect of the FA Vermikom on blood parameters, as well as milk physicochemical and mineral composition and yield in lactating dairy cows.

Materials and Methods: A total of 30 Holstein cows, with an average weight of 650±5 kg, were randomly divided into three groups of 10. Over a period of 5 months, each group was fed one of three diets: Mixed main diet without supplements (control), main diet supplemented with 2% Vermikom, and main diet supplemented with 4% Vermikom.

Results: Hematological parameters, productivity, and physicochemical and mineral composition of milk from animals provided the FA Vermikom were higher than those of the control group. In the Vermikom groups, the hemoglobin content was higher by 5.75%, calcium by an average of 10.8%, and total protein by 2.5%. The average daily milk yield was also higher by 8.4% than the control group. Regarding the mineral composition of the milk, the content of calcium, phosphorus, and iron exceeded that of the control on average by 2.9%, 3.4%, and 14.8%, respectively.

Conclusion: We propose introducing 4% Vermikom into the diet of dairy cows based on the study results. Future research will expand our knowledge regarding cows' needs for all recommended nutrients, thereby improving animal productivity and milk quality. The results obtained contribute to further expanding the food base of animal husbandry in the Republic of Kazakhstan.

Keywords: diet, feed additive, hematology, milk productivity, milk quality, vermiculite.