Effects of dietary gallic acid supplementation on performance, antioxidant status, and jejunum intestinal morphology in broiler chicks

Gallic acid (GA), widely distributed in plants and feeds, is known to have a diverse range of activities such as anti-oxidant, anti-inflammatory, antibacterial, anti-allergic, anti-mutagenic, and anticarcinogenic. The purpose of this study was to investigate the efficacy of inclusion of dietary GA at levels 0, 25, 50, 75, 100, or 150 mg/kg on growth performance, antioxidant status, and jejunum intestinal morphology of broiler chicks. In total, 630 one-day-old Arbor Acres (AA) male broiler chicks were randomly allotted to 6 treatment groups for a period of 6 weeks. The results indicate that dietary addition of GA at 75 to 100 mg/kg improved feed conversion efficiency in both the grower (d 21 to 42, P = 0.045) and overall (d 1 to 42, P = 0.026) periods. Dietary addition of GA at a concentration >= 100 mg/kg was able to exhibit higher breast muscle ratio at 42 d (P = 0.043). Interestingly, dietary GA inclusion level from 50 to 100 mg/kg reduced the crypt depth (P = 0.009) and increased the villus height: crypt depth ratio (VCR) of the birds (P = 0.006). Dietary supplementation of GA at 100 mg/kg decreased plasma malondialdehyde (MDA) content at 42 d of age (P = 0.030). Moreover, dietary addition of GA linearly increased plasma total antioxidant capacity (P = 0.039) and plasma total superoxide dismutase activities (P = 0.049) at 21 d of age. However, analysis of plasma biochemical markers revealed that dietary supplementation of GA did not exhibit beneficial health effects. Overall, we conclude that 75 to 100 mg/kg of GA are suitable for enhanced growth performance and health benefits in a broiler diet.