Quercetin extracted from Sophora japonica flower improves growth performance, nutrient digestibility, cecal microbiota, organ indexes, and breast quality in broiler chicks

Objective: The objective of this study was to evaluate the effects of supplementing quercetin extracted from Sophora japonica flower (QS) to the diet of broiler chicks on their growth performance, apparent nutrient digestibility, cecal microbiota, serum lipid profiles, relative organ weight, and breast muscle quality. Methods: A total of 1,088 1-day-old broiler chicks (mixed sex) were randomly assigned to four groups based on the initial body weight (43.00 +/- 0.29 g). The experimental period was 35 days (starter, days 0 to 7; grower, days 7 to 21; finisher, days 21 to 35). There were 17 replicate cages per treatment and 16 birds per cage. Dietary treatments consisted of birds receiving basal diet without quercetin as the control group and treatment groups consisted of birds fed basal diet supplemented with 0.2, 0.4, or 0.6 g/kg QS. Results: With the increase of the QS dosage, body weight gain during days 0 to 7 (p = 0.021), 7 to 21 (p = 0.010), and 1 to 35 (p = 0.045), feed intake during days 0 to 7 (p = 0.037) and 1 to 35 (p = 0.025), apparent dry matter digestibility (p = 0.008), apparent energy retention (p = 0.004), cecal lactic acid bacteria counts (p = 0.023), the relative weight of breast muscle (p = 0.014), pH value from breast muscle (p<0.001), and the water holding capacity of breast muscle (p = 0.012) increased linearly, whereas the drip loss from breast muscle (p = 0.001) decreased linearly. Conclusion: The addition of QS in the diet of broiler chicks had positive effects on the breast muscle yield and breast muscle quality, and improved the dry matter digestibility and energy retention by increasing cecal beneficial bacteria counts, thus improving growth performance.