This study investigated the effects of butyric acid glycerides (BAG) and a multicomponent phytogenic product (MPH), both individually and in combination, on growth performance, carcass traits, hematological parameters, immune responses, gut morphology, and the expression of tight junction genes in broiler chickens challenged with coccidiosis. A total of 550 one-day-old male Ross 308 chicks were assigned to 5 treatment groups: negative control (NC; basal diet without challenge), positive control (PC; basal diet with coccidiosis challenge), PC supplemented with BAG (PC+BAG), PC supplemented with MPH (PC+MPH), and PC supplemented with both BAG and MPH (PC+BAG+MPH). The coccidial challenge, using a mixed Eimeria species inoculum, was administered on day 14. Results demonstrated that the combined PC+BAG+MPH treatment significantly improved final BW (2,798 g), ADG (65.6 g/day), and performance index (375) compared to the PC group (2,494 g, 58.3 g/day, and 289; P < 0.05), with values not significantly different from the NC group (2,926 g, 68.6 g/day, and 403; P > 0.05). Feed conversion ratio was significantly better in the PC+BAG+MPH (1.69) and NC (1.68) groups compared to the PC group (1.83; P < 0.05). Intestinal morphology was also significantly improved in the PC+BAG+MPH group, with increased villus height and villus height-to-crypt depth ratios in the duodenum, jejunum, and ileum (P < 0.05). All supplemented groups exhibited reduced oocyst excretion and lesion scores, with the greatest reductions observed in the PC+BAG+MPH group (P < 0.05). Additionally, this group showed increased serum IgG and IgA concentrations, upregulated expression of jejunal JAM-2, claudin, and ZO-1 genes, and a decreased heterophil-to-lymphocyte ratio compared to the PC group (P < 0.05). While the PC+BAG and PC+MPH treatments individually yielded improvements in certain growth and gut health parameters, these effects were less pronounced than those observed with the combined treatment. In conclusion, dietary supplementation with both BAG and MPH effectively mitigated the adverse effects of Eimeria challenge by improving growth performance, intestinal morphology, immune status, and mucosal barrier integrity in broiler chickens.
