With the increasing use of antibiotics in pig farming, there is a growing need for alternative solutions to support animal health and productivity, which underscores the importance of studying the effectiveness of phytogenic additives in pig feeding. The study is dedicated to evaluating the impact of a phytogenic feed additive based on dried garlic and caraway on productivity, metabolic status, and the microbiota of the large intestine of replacement gilts of the (LW × L) genotype. The experiment was conducted under production conditions on two groups of animals (n = 80), which received either the basic diet without the additive (control) or the feed additive at a dose of 0.10% of the compound feed mass (experimental group). Starting from the 17th week of growth, the experimental group of gilts showed a significant advantage in live weight (p ≤ 0.001) and average daily gains (p ≤ 0.01), which persisted until the 28th week of age. The overall animal survival rate was 95% compared to 85% in the control group, indicating an improvement in physiological condition and stress resistance. Biochemical serum indicators showed an increase in albumin content, protein coefficient, calcium, phosphorus, and iron, while a decrease in γ-glutamyltransferase and indirect bilirubin was observed, reflecting optimisation of protein, mineral, and pigment metabolism, and a hepatoprotective effect. Bacteriological analysis revealed an increase in the proportion of Lactobacillus amylovorus, L. reuteri, Clostridium butyricum, and Eubacterium rectale, and a decrease in Staphylococcus aureus, S. epidermidis, and Streptococcus suis, indicating restoration of microbial balance, increased production of short-chain fatty acids, and colonisation resistance of the intestine. It was established that the phytogenic additive used exhibits a combined stimulating effect, simultaneously influencing the microbiota, metabolism, and physiological adaptation of the animals
biochemical blood indicators, immunomodulation, sustainable pig farming, large intestine, phytobiotic