Anticoccidial Efficacy of Solid-Dispersion Formulations Containing Curcuma longa and Piper longum Extracts Against Eimeria tenella Infection in Broiler Chickens.

Coccidiosis is one of the most economically important parasitic diseases in poultry, causing intestinal damage, impaired nutrient utilization, and substantial production losses. The extensive use of anticoccidial drugs has raised concerns regarding drug resistance, chemical residues in poultry products, and the environmental burden associated with veterinary drug use, highlighting the need for complementary control strategies. This study evaluated the anticoccidial efficacy of phytogenic formulations containing Curcuma longa and Piper longum extracts prepared using a solid-dispersion technique designed to enhance the dissolution characteristics of poorly water-soluble phytogenic compounds. The in vitro activity of the formulations was evaluated against mixed Eimeria spp. field-isolated oocysts using scanning electron microscopy (SEM) to examine ultrastructural alterations, whereas in vivo efficacy was investigated in broiler chickens experimentally challenged with Eimeria tenella. Cecal lesion scores, oocyst shedding, and growth performance were evaluated as indicators of infection severity and treatment response. SEM observations revealed marked structural damage to mixed Eimeria spp. oocysts following exposure to the phytogenic formulations. In the animal trial, all phytogenic treatment groups exhibited lower cecal lesion scores and reduced oocyst shedding than the infected control group. Among the phytogenic formulations evaluated, the combination containing 6 g/kg P. longum (T3) tended to produce the lowest numerical lesion score and oocyst shedding, although differences among phytogenic treatments were limited. Although some treatment groups also exhibited numerically favorable growth performance under challenge conditions, these observations should be interpreted cautiously because the study was designed primarily as a preliminary evaluation of anticoccidial efficacy, and feed intake and feed conversion ratio were assessed without independent pen-level replication. The observed biological responses may be associated, in part, with the improved dissolution characteristics afforded by the solid-dispersion formulation; however, this proposed mechanism was not directly investigated in the present study. In conclusion, solid-dispersion formulations containing C. longa and P. longum extracts demonstrated promising anticoccidial activity against experimental E. tenella infection and support further investigation as promising phytogenic candidates for complementary coccidiosis control strategies in broiler chickens.