Effects of ginger ethanol extract on growth performance, antioxidant capacity and intestinal microbiota of broilers.

Ginger ethanol extract (GEE), an oily bioactive compound derived with antioxidant and anti-inflammatory properties that is extracted from ginger through ethanol extraction, remains unexplored in terms of its effect on broiler growth and antioxidant mechanism. This study aimed to optimize the extraction process of GEE and evaluate the effect of various concentrations of GEE on growth performance, antioxidant capacity, and intestinal microbiota in broilers. The optimal extraction conditions were: solid-liquid ratio of 8 mL/g using 75 % ethanol, 1 h extraction time. In this condition, the main compound 6-gingerol in GEE reached 10.01 mg/g. A total of 240 one-day-old white feather 817 broilers were assigned to 4 groups with 6 replicates of 10 chickens each: control (basal diet), 0.1 %, 0.2 % and 0.3 % GEE supplementation, The feeding trial lasted for 42 days. Results showed that 0.1 % GEE significantly increased final body weight, ADG, and ADFI by day 42, although 0.3 % GEE reduced early feed intake, it improved ADFI later (P < 0.05). The 0.1 % GEE improved crude protein and phosphorus metabolism, 0.3 % GEE improved phosphorus metabolism (P < 0.05). In addition, 0.2 % GEE improved cooked meat rate, and 0.3 % GEE improved meat pH and color (P < 0.05). Serum analysis indicated that 0.1 % GEE significantly decreased ALT and AST levels, increased serum CAT and liver SOD activity (P < 0.05), which indicate that the GEE enhances the antioxidant capacity and liver protection function. Hematoxylin-Eosin analysis indicated the addition of 0.1 % GEE increased jejunal villus length and reduced abdominal fat cell diameter with (P < 0.05). Microbial analysis showed a significant increase in Firmicutes and Faecalibacterium abundance, while a decrease in Bacteroidota in the 0.1 % GEE group (P < 0.05). In conclusion, the addition of 0.1 % GEE can improve the growth performance, meat quality, lipid and nutrient metabolism of broilers, and protect liver and intestinal health.