# Comparative effects of Dracocephalum moldavica L. and probiotic on performance and health parameters of broiler chickens challenged by dexamethasone-induced stress

## TL;DR

This study compares the effects of a medicinal plant and a probiotic on broiler chickens under stress, finding both improve performance and gut health.

## Contribution

The novel contribution is evaluating Dracocephalum moldavica L. and a probiotic in mitigating dexamethasone-induced stress in broilers.

## Key findings

- Dexamethasone challenge reduced performance, carcass traits, and ileum villus height but decreased cecal E. coli and coliform counts.
- Lactofeed and Dracocephalum moldavica L. improved feed intake, body weight gain, white blood cell count, and intestinal health.
- Both additives mitigated stress effects on performance and gut health regardless of dexamethasone exposure.

## Abstract

Environmental stressors negatively affect poultry productivity by increasing oxidative stress levels. This study evaluated the performance and health status of broilers supplemented with either the medicinal plant Dracocephalum moldavica L. powder (DP) or a commercial probiotic (Lactofeed) in the context of oxidative stress induced by dexamethasone.

A total of 300 one-day-old chicks were enrolled in a completely randomized design with a factorial arrangement of six treatments, in each consisting five replicates of 10 chicks. The experimental treatments were: 1) basal diet without feed additives and no challenge, 2) basal diet supplemented with 0.01% Lactofeed, 3) basal diet with 0.4% DP, 4) basal diet and challenged with dexamethasone (2 mg/kg body weight), 5) basal diet with 0.01% Lactofeed and challenged with dexamethasone, and 6) basal diet with 0.4% DP and challenged with dexamethasone. Growth performance, carcass traits, and internal organ weights were evaluated. Gastrointestinal pH and ileum histology were assessed on days 28 and 42, while cecal microbial counts were determined on days 14, 28, and 42. Serum samples collected on days 14, 28, and 42 analyzed for antibody titers against Newcastle disease and avian influenza viruses, along with white blood cell counts.

The dexamethasone challenge negatively impacted performance, certain carcass traits, white blood cell count, and ileum villus height (p = 0.039), while it reduced cecal Escherichia coli and coliform counts (p = 0.001). It suppressed humoral immune response to the Newcastle disease virus on day 28, whereas on day 42, it enhanced the response. Lactofeed and DP additives significantly improved feed intake, body weight gain, white blood cell count, intestinal histology, and microbiota, largely irrespective of dexamethasone challenge.

While dexamethasone challenge induced various physiological stresses in broilers, both Lactofeed and DP feed additives demonstrated potential in mitigating these effects, improving overall performance and gut health parameters regardless of stress conditions.