Effects of phytogenic feed additive on growth performance, gut health, and antioxidant capacity in broiler chickens challenged with pathogenic Eimeria tenella

This study aimed to evaluate a dietary phytogenic preparation (PT) comprising Ginkgo biloba L. leaves and mangosteen extract in broilers challenged with pathogenic Eimeria tenella. One-day-old Arbor Acres broilers (n = 600) were randomly assigned to a treatment group (six replicate floor pens/treatment, 20 chicks/replicate): non-challenged and control diet-fed negative control group (NC); E. tenella challenged and control diet-fed positive control group (PC); and PC + PT (50, 100, or 200 mg PT/kg of diet). On day 14, all groups except NC were gavaged with 1.0 × 10⁴ oocysts of E. tenella. The Eimeria challenge impaired (P < 0.05) body weight, which was mitigated by dietary PT on days 21 and 28. Furthermore, E. tenella challenge increased cecal lesion scores; however, dietary PT preparations reduced (P < 0.001) these lesions. Moreover, Eimeria challenge impaired ileal morphology; however, dietary PT alleviated these changes. All E. tenella-challenged broilers exhibited lower total short-chain fatty acid content in their cecal digesta and partially lowered (P = 0.055) ileal digestibility of crude fat being the latter linearly improved by dietary PT preparations (P < 0.05). Nitric oxide concentrations in the serum and cecal mucosa were elevated after Eimeria challenge; however, they were relieved by dietary PT in a concentration-dependent manner. Serum total cholesterol and high-density lipoprotein cholesterol concentrations in the Eimeria-challenged groups were lower than those in the NC group. Eimeria challenge also decreased catalase activity in the liver and superoxide dismutase activity in the cecal mucosa, but increased glutathione peroxidase activity in the cecal mucosa compared with that in the NC group. Increasing dietary PT concentrations increased serum (linear effect, P = 0.031) and liver (linear effect, P = 0.034) glutathione peroxidase levels and superoxide peroxidase activity in the cecal mucosa (quadratic effect, P = 0.015). Collectively, dietary PT shows promising potential as a nutritional solution to reduce avian coccidiosis via the modulation of innate and antioxidant markers and the alleviation of Eimeria-specific cecal lesions.