Dietary supplementation with ginger essential oil nanoemulsion improves growth performance and modulates oxidative and inflammatory biomarkers in heat-stressed growing rabbits

This study aimed to evaluate the effects of ginger essential oil nanoemulsion (GEONE) supplementation on growth performance, feed efficiency, and overall health status in heat-stressed growing rabbits. A total of 96 healthy 5-week-old APRI male rabbits were randomly assigned to four homogeneous groups (24 rabbits per group) and fed diets supplemented with 0, 100, 200, or 400 mg of GEONE per kilogram of feed. Dietary supplementation with 200 mg GEONE/kg diet significantly improved growth performance, as evidenced by increased average daily weight gain by 8.14% and dressing percentage by 7.77%, alongside significant reductions in feed conversion ratio by 8.65%, rectal temperature by 1.63% and respiration rate by 9.06%. Liver enzyme activities declined in a dose-dependent manner, while total blood proteins, their fractions, and thyroid hormone concentrations were significantly elevated. Concurrently, levels of total cholesterol, triglycerides, urea, creatinine, and cortisol were significantly reduced. Antioxidant capacity was enhanced, reflected by higher total antioxidant activity and increased activities of catalase, glutathione peroxidase, and superoxide dismutase. Immune function was also strengthened, with notable elevations in immunoglobulins M and G by 16.95% and 38.29%, respectively. Indicators of oxidative stress, including malondialdehyde, protein carbonyls, and 8-hydroxy-2′-deoxyguanosine, were markedly reduced, while concentrations of pro-inflammatory cytokines were significantly lowered, and nitric oxide levels were significantly increased. Histological evaluations further corroborated these findings, demonstrating protection against heat stress through preservation of normal liver and kidney architecture. In conclusion, supplementation with 200 mg of GEONE/kg of diet effectively improved growth performance, feed utilization, liver and kidney function, antioxidant defense, immune response, and inflammatory regulation in fattening rabbits exposed to summer heat stress.