Dietary tea tree (Melaleuca alternifolia) essential oil as alternative to antibiotics alleviates experimentally induced Eimeria tenella challenge in Japanese quails.

Coccidiosis is one of the most common infectious diseases seen in Japanese quails. The current study was conducted to evaluate the impact of tea tree essential oil (TTEO) on growth performance and intestinal health of quails in response to Eimeria tenella challenge. A total of 250 Japanese quails were divided into five treatments: untreated uninfected (negative control); untreated infected (positive control); infected + Amprolium; infected and 1% TTEO; infected and 2% TTEO. Except negative control, all groups were orally dosed with 5 × 104 sporulated oocysts of E. tenella. The results revealed that supplementation of 1% TTEO and treatment of amprolium improved feed intake, weight gain and feed conversion ratio in infected quails compared to the positive control. Similarly, lesion score and mortality was significantly (p < 0.01) reduced in quails supplemented with 2% TTEO and amprolium treated birds. Moreover, oocysts counts and histological features of caecum in infected birds were reversed in 1% TTEO and amprolium treatment. The histological findings of amprolium and 1% TTEO supplemented quails showed intact intestinal villi with mild sloughed epithelium. In conclusion, 1% TTEO can be safely used to control coccidiosis in Japanese quails as natural effective compound. © 2022 Wiley-VCH GmbH.