Abstract

Background:
In recent years, interest in the use of probiotics and phytogenic supplements in animal husbandry has grown significantly to improve animal health and productivity.

Aim:
This study evaluates the effects of dietary supplementation with a probiotic alone and in combination with three medicinal herbs - milk thistle (Silybum marianum), nettle (Urtica dioica), and dandelion (Taraxacum officinale), on growth performance, biochemical blood and key innate immune parameters in broiler chickens.

Methods:
An experimental, completely randomized design was conducted with 180 one-day-old Ross 308 broilers, allocated into three groups of 60 birds each with 3 replications. The feeding trial lasted from day 1 to 42 days of age. The groups were: basal diet (control), basal diet + probiotic, and basal diet + probiotic + herbs. Key parameters included body weight, blood biochemical indicators, and immune markers.

Results:
Supplementation with probiotic and herbs significantly improved broiler growth during days 1–14 and 29–42 (P < 0.05), with the highest values observed in the group receiving the combined supplementation. Biochemical parameters, including glucose, total protein, and lipids, showed favorable changes in the supplemented groups. Immune indicators (APCA, lysozyme, beta-lysins) were increased in the third group compared to the control.

Conclusion:
The combined supplementation of probiotics and herbs positively affects growth and the immune system in broilers. The results support the potential of this combination as a natural alternative to antibiotics for improving poultry health and productivity. Future studies should assess the effects in larger flocks, with different additive doses, and include a comparative antibiotic group to more precisely determine their efficacy and practical applicability.

Key words: Blood biochemistry; Herbal supplementation; Immune response; Natural alternatives.