Influences of flavonoid (quercetin) inclusion to corn-soybean-gluten meal-based diet on broiler performance

Quercetin (a predominant flavonoid) is considered to have antimicrobial and antioxidant properties. This trial was conducted to evaluate the impact of graded doses of quercetin (QS) on growth efficiency, nutrient retention, faecal score, footpad lesion score, tibia ash and meat quality. In a 32-day feeding test, a total of 576 1-day-old Ross 308 broilers (male) were allocated arbitrarily with an average body weight of 41 ± 0.5 g. The trial had four dietary treatments with eight repetitions of 18 birds per pen and a basal diet incorporating 0%, 0.02%, 0.04% and 0.06% of QS. As the QS dosage increased, body weight gain tended to increase linearly on Days 9-21 (p = 0.069) and overall period (p = 0.079). Similarly, feed intake increased (p = 0.009) linearly with the increasing doses of QS on Days 9-21. Likewise, there was a linear improvement in dry matter (p = 0.002) and energy (p = 0.016) digestibility after QS administration. Moreover, the inclusion of QS supplement (0%-0.06%) linearly increased (p = 0.012) tibia ash in broilers. However, the faecal score and footpad lesion score showed no significant outcome (p > 0.05). By giving broilers a graded amount of QS, the relative organ weights of breast muscle (p = 0.009) and spleen (p = 0.006) improved linearly, meat colour lightness increased (p = 0.015), redness tended to improve (p = 0.065) linearly and drip loss decreased (p = 0.015) linearly. The inclusion of QS in the graded-level diet led to improvements in growth efficiency, nutrient absorption, meat quality and tibia ash, which recommended it as a beneficial feed additive for the broiler.