Physiological and microbial responses to periodic drinking-water supplementation with Chenopodium ambrosioides extract in broiler chickens.

Phytogenic extracts may influence poultry performance through changes in systemic oxidative status and intestinal microbial populations. This study evaluated the effects of periodic Chenopodium ambrosioides extract (CAE) supplementation through drinking water on growth performance, carcass characteristics, serum biochemical and oxidative status, cecal bacterial populations, and microbiological stability of broiler meat. A total of 210 five-day-old Ross 308 chicks were randomly assigned to 3 groups: an unsupplemented control and 2 CAE treatments receiving 3 or 6 mL/L of drinking water every third day from d 5 to 34. The methanolic CAE contained 22.2 mg gallic acid equivalents/g of total phenolic compounds and 1.13 mg quercetin equivalents/g of flavonoids, with DPPH SC50 values ranging from 15.66 to 81 mg/mL. CAE supplementation improved feed conversion ratio, with the lowest value observed in supplemented birds compared with the control (1.28 vs. 1.47; P = 0.026), while feed intake decreased without a significant change in body weight. Water intake was also reduced by CAE supplementation (P = 0.034). Carcass responses were selective, with lower relative weights of the heart, gizzard, and spleen and increased abdominal fat deposition in CAE-treated birds (P < 0.05). At 6 mL/L, CAE increased serum HDL concentration (31.46 vs. 28.29 mg/dL; P = 0.002), reduced urea (34.12 vs. 41.61 mg/dL; P = 0.031) and malondialdehyde concentrations (3.31 vs. 3.62; P = 0.001), and increased glutathione S-transferase activity and reduced glutathione levels (P < 0.05). These responses indicate changes in systemic biochemical and oxidative status following CAE supplementation. In the cecum, CAE produced dose-dependent reductions in total bacterial and coliform populations, accompanied by increased Lactobacillus counts (P < 0.001). Meat microbiological stability was also improved, as indicated by lower aerobic plate counts on d 10 in birds receiving 6 mL/L CAE (P < 0.001). Overall, periodic supplementation with C. ambrosioides extract through drinking water, particularly at 6 mL/L, was associated with improved feed efficiency and coordinated changes in systemic oxidative status and measured cecal bacterial populations, together with reduced microbial counts in broiler meat.