Dietary violacein suppresses the deleterious effects of experimentally induced coccidiosis in broiler chickens

Poultry coccidiosis is a catastrophic parasitic disease and the industry is currently seeking alternative compounds to replace conventional antibiotics. Accordingly, the current study determined the effect of dietary violacein supplementation on growth performance and anticoccidial indices of Eimeria-infected broiler chickens. A total of 336-day-old “Ross 308” broiler chicks were allotted to 6 treatments: that is, positive control (PC), negative control (NC), 1 treatment with salinomycin (6 ppm), and 3 treatments with different violacein concentrations (10, 15, 20 ppm). Experimental coccidiosis was induced in all chickens (except NC) by inoculating 3.2 × 105 sporulated oocysts. The treatment with 15 ppm violacein (VIO 15) significantly improved chicken growth performance compared to PC. Furthermore, significant reductions in lesion score, oocyst per gram of feces (OPG), and oocysts index (OI) were observed in the VIO 15 and the salinomycin treatments compared to other treatments. Violacein was reported as ‘moderately effective’ on Eimeria spp. based on the “anticoccidial index (ACI),” whereas “reduction in lesion score (RLS)” and “percentage anticoccidial activity (POAA)” indices designated its 15 ppm treatment as “highly sensitive” on them. Additionally, VIO 15 downregulated “interleukin-8 (IL-8)” and “interleukin-6 (IL-6)” compared to PC, in both spleen and cecal tonsils. Besides, expression levels of “chemokine C–C motif ligand 2 (CCLi-2),” were reduced in cecal tonsils of VIO 15 broiler chickens compared to PC. Conclusively, dietary violacein supplementation suppressed the deleterious effects of coccidial infection in broiler chickens with improved growth, and its 15 ppm level is recommended for use.