The article is concerned with immune status evaluation at replacement cattle aged 12 months when using a tissue biostimulator based on antler deer slaughterhouse tankage. The experiment on replacement young cattle took place at on-the-farm conditions of JSC “Uchkhoz “Prigorodnoe,” the Industrial District of Barnaul, Altai Territory. The researchers administered the tissue biostimulant to the experimental animals aged 1 to 12 months of rearing monthly with 30 days intervals at different doses according to the schedule: the first experimental group: aged 1 to 5 months – 2 ml per head, aged 6 to 11 months – 4 ml per head, aged 12 months – 8.0 ml per head; the second experimental group: aged 1 to 5 months – 3 ml per head, aged 6 to 11 months – 6 ml per head, at 12 months – 15.0 ml per head; the third experimental group: aged 1 to 5 months – 4 ml per head, aged 6 to 11 months – 8 ml per head, aged 12 months – 16.0 ml per head. Control animals were injected with normal saline: aged 1 to 5 months – 3 ml per head, aged 6 to 11 months – 6 ml per head, aged 12 months – 15 ml per head. The studies found that the optimal dose and tissue biostimulant dosing schedule, promoting the relative content of the tE-POK subpopulations by 5.0% (p ≤ 0.01), bE-POK by 4.9% (p ≤ 0.001), pE- ROC by 5.0% (p ≤ 0.05) EM-ROC by 3.1% (p ≤ 0.01), decreasing vE-ROC by 2.6% (p ≤ 0.05) and increasing in the absolute content of bEROC by 72.4% (p ≤ 0.05), respectively, are 3 ml per head for aged 1 to 5 months, 6 ml per head aged 6 to 11 months and 15.0 ml per head aged 12 months.