Anticoccidial effect of bitter apple ( <i>Citrullus colocynthis</i> ) seed powder and organic selenium nanoparticles in mitigating <i>Eimeria tenella</i> -induced challenge in quails

Amprolium is commonly used to control coccidiosis, but growing resistance is compelling reason to search for alternatives. This study tested bitter apple (BA) and organic selenium nanoparticles (Org-SeNPs) against Eimeria tenella in quails. A total of 420 one-day-old quails were divided into six groups: negative control, positive control (Eimeria-infected), Amprolium-treated, Org-SeNPs-treated (0.3 ppm), BA-treated (1 g/kg), and a combination of bitter apple (BA) and Org-SeNPs. The negative control group consistently exhibited superior performance metrics. Supplementation with BA, Org-SeNPs, or their combination mitigated reductions in FI and WG caused by infection, though not to the extent observed in the negative control or Amprolium groups. Lesion scoring and oocyst counts revealed significant reductions in Eimeria tenella severity with all treatments, with Amprolium being the most effective. Mortality rates were highest in the positive control and significantly reduced in treated groups. Cecal histomorphology analysis indicated that treated groups showed improved villus height-to-crypt depth (VH:CD) ratios compared to the positive control. Amprolium-treated quails exhibited the most favourable intestinal architecture among the treated groups, followed by Org-SeNPs and BA. These findings highlight the potential of BA and Org-SeNPs as alternative therapeutic agents for managing coccidiosis, though their efficacy is lower than that of Amprolium.