Therapeutic effects of Gardenia jasminoides Ellis on salpingitis in laying hens: mechanisms of inflammatory regulation and egg quality improvement.

BACKGROUND

Salpingitis (SALP) severely affects egg production and quality in laying hens, and conventional antibiotic therapies are limited by drug residues and antimicrobial resistance. Gardenia jasminoides (GF) is a traditional Chinese medicine that exhibits anti-inflammatory properties. However, its efficacy against SALP remains underexplored.

METHODS

A 3-week trial assigned 108 hens to blank, model, positive control, and GF-treated groups (0.5%, 1.0%, and 1.5% dietary supplementation). SALP was induced in all groups, except the blank control group, via intrafallopian infusion of white iodophenol solution. The parameters assessed included egg production, quality (weight, shell hardness, and thickness), serum hormones namely estradiol (E2), prostaglandin E2 (PGE2), luteinizing hormone (LH), and follicle-stimulating hormone (FSH), inflammatory cytokines including interleukin-2 (IL-2), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ), and eggshell ultrastructure.

RESULTS

GF significantly restored egg production rate (P < 0.01), increased egg weight (P < 0.01), and improved shell hardness (P < 0.01) and thickness (P < 0.05). GF downregulated IL-2 (P < 0.05) and IL-6 (P < 0.01) expression, reduced the incidence of blood spots (P < 0.05), and enhanced ultrastructural integrity, including smoother surfaces and reduced palisade layer defects. Hormonal levels (E2, PGE2, LH, and FSH) were significantly elevated in the GF groups (P < 0.01).

CONCLUSIONS

GF supplementation mitigated SALP-induced egg quality deterioration through anti-inflammatory action and ultrastructural repair, demonstrating dose-dependent efficacy. These findings suggest that GF shows potential as a candidate to reduce antibiotic use in SALP treatment for the treatment of poultry SALP.