Attenuated Vaccine Associated with Organic Acids in the Control of Coccidiosis and Promotion of Intestinal Health in Broiler Chickens

ABSTRACT This study evaluated the efficacy of an attenuated coccidiosis vaccine containing early-maturing Eimeria strains, combined with a nutritional additive, as an alternative to anticoccidial drugs in broilers. A total of 672 male Ross chicks were allocated in a 4×2 factorial design (4 control programs: anticoccidial, additive + anticoccidial, vaccine and additive + vaccine vs. challenged or not with live coccidiosis vaccine and Escherichia coli), totaling eight treatments with six replicates of 14 birds. Data were analyzed using ANOVA (GLM procedure, SAS software). Challenged birds showed reduced productive performance (p<0.05) regardless of treatment, with no differences between control programs. The vaccine improved jejunal morphometry, notably villus width and crypt depth, and was associated with enhanced regenerative capacity at 28 days. No significant effects (p>0.05) were observed for mitotic index. Serum FITC-d levels were lower (p<0.05) in challenged birds, and foot coloration was higher with the vaccine plus additive. These findings support the use of an early attenuated vaccine as a viable and effective alternative to traditional anticoccidials, especially when paired with nutritional additives.