Goats are an excellent animal model for research on some physiological and pathophysiological processes in humans. The search for supplements that prevent homeostasis disorders and strengthen the immune system is necessary to reduce the risk of many diseases in both humans and animals. The aim of the study was to analyze the effect of supplementation with a mixture of dried extracts of Curcuma longa and Rosmarinus officinalis on the expression of acute-phase protein (SAA, HP, CRP, LALBA, AGP, CP, FGA, FGB, and FGG), cathelicidin (BAC5, BAC7.5, BAC3.4, MAP28, MAP34, and HEPC), beta-defensin-1 (GBD1, DEFB1), and beta-defensin-2, and cytolytic protein (LIZ and LF) genes in the livers of young castrated bucks of the Polish White Improved breed. The higher expression of LF in the control group suggests that it is important for the first line of hepatic immune defense and its expression is downregulated by the mixture of turmeric and rosemary extracts; thus, the spice–herb mixture mutes its activity. The lower expression of FGB and the higher expression of BAC5 genes in the livers of healthy, young castrated bucks who were administered the supplement suggest the silencing effects of the mixture on the acute-phase response and the stimulating effect on the antimicrobial activity of the immune system.