The Effects of Chicory Aqueous Extract on Antioxidant Capacity, Immune Response, and Intestinal Function in Broilers

In the broiler production industry, antibiotics such as florfenicol are widely used. Although these antibiotics exert therapeutic effects against bacterial diseases, they can induce a series of physiological alterations in broilers under certain exposure scenarios. This study aimed to investigate the effects of chicory aqueous extract (CAE) on broiler growth performance, immune function, and intestinal health, and to compare the impacts of CAE and florfenicol exposure on the physiological status of broilers. A total of 200 one-day-old broilers were randomly divided into five groups (5 replicates per group): the blank control group (NC) drank tap water freely, the florfenicol group (FFC) was given 0.15 g/L of florfenicol solution in the drinking water, the CAE groups were given 1.25 g/L (LCAE), 2.5 g/L (MCAE), and 5 g/L (HCAE) of CAE in the drinking water, respectively. The experimental period was 42 days. The results showed that the addition of CAE to drinking water could significantly improve the growth performance of broilers, specifically manifested as increased body weight and a significantly decreased feed-to-gain ratio (F/G) (p < 0.05). Regarding immune function, CAE enhanced immune capacity by increasing immune organ indices, serum antibody titers, and serum levels of immunoglobulin A (IgA) and immunoglobulin G (IgG) (p < 0.05). In terms of intestinal function, CAE significantly increased villus height (VH) and villus-crypt ratio (V/C), elevated activities of digestive enzymes including chymotrypsin, α-amylase, and lipase, and raised both secretory immunoglobulin A (sIgA) content and Occludin mRNA relative expression levels (p < 0.05), thereby improving intestinal digestion and absorption. Additionally, CAE enhanced serum superoxide dismutase (SOD) activity and reduced malondialdehyde (MDA) content (p < 0.05), effectively enhancing the antioxidant capacity of broilers. Notably, compared with the NC group and all CAE-treated groups, broilers in the FFC group exhibited significantly reduced growth performance, suppressed immune function, and evident damage to intestinal tissue structure and physiological functions. Comprehensive analysis indicates that CAE can effectively promote broiler growth and development, enhance immune status and intestinal digestive-absorptive function, and enrich gut bacteria such as Lactobacillus and Bifidobacterium, thus optimizing intestinal microbiota composition. Among the gradient doses tested in this study, the 2.5 g/L dose of CAE demonstrated the best overall effect, suggesting that CAE may exert beneficial physiological effects under the present experimental conditions, and further investigations are needed to assess its practical application potential.