Quercetin dihydrate powder

A total of 480 (1-day-old) healthy Arbor Acre broilers (similar in body weight, 47.17 ± 1.26 g) were obtained from a commercial company (Yinong Poultry, Harbin, China). The chickens were randomly divided into four experimental groups with six replicates per group and 20 broilers per replicate.
Broilers were raised in a netted stainless steel cage (526 × 423 × 381 mm) with ad libitum access to feed and fresh water, and controlled ventilation. All chickens experienced 16 h of continuous light every day for 42 days. Temperature was maintained at 32–34°C for the first 3 days and decreased to 24°C by the end.
The experimental diets were formulated based on corn and soybean meal according to Chinese Broiler Feeding Standards (GB/T5916-2020) to meet the nutrient requirements of broilers (Table 1). And four concentrations of quercetin were added to the diet: 0.00, 0.02, 0.04, and 0.06%. Feeding was divided into two phases: the starter phase from 1 to 21 days and the grower phase from 22 to 42 days. Quercetin dihydrate powder with 97% purity (Sigma-Aldrich, United States) was mixed in basal diet.

Arbor Acre broilers (480 chickens, 1 day old, healthy, similar body weight) from a commercial company (Yinong Poultry Limited Company, Harbin, China) were purchased and randomly divided into 4 groups with 6 replicates per group and 20 broilers per replicate. The broilers were housed in wire cages (four-stacked cages; width: 52.6 cm; depth: 42.3 cm; height: 38.1 cm). Lighting (16 h light : 8 h darkness) was provided during the 6-week experimental period, and temperature was maintained at 32 to 34°C in the starting 3 days and decreased by 2 to 3°C per week to a final temperature of 24°C. Humidity of the experimental room varied from 60% to 65%. Experimental diets and water were available ad libitum. The composition of the basal diets is shown in Table 1 (NY/T33-2004), with 4 levels of quercetin: 0.00%, 0.02%, 0.04%, and 0.06% of quercetin in the diet. Quercetin dihydrate powder with 97% purity was purchased from Sigma-Aldrich Company and mixed with basal diets and was offered in mash form (5 mm) after grinding according to the methods of Yang et al. in 2020 [20 (link)].