Effect of a microencapsulated mixture of botanicals on broilers artificially infected with Eimeria

This study evaluated the efficacy of a microencapsulated botanical blend (AviPower®2, AP2) in chickens artificially infected with Eimeria.
Nine-hundred-day-old chicks were distributed into 60 pens and four treatments (n=15): UUC, control feed, uninfected; IUC, control feed, infected; SAL, feed with 66 ppm salinomycin, infected; AP2, feed with 100 g/T AP2, infected. On d14, chickens were orally infected with E. acervulina and E. tenella. Performance was recorded until d34. On d21, one chicken per cage was sacrificed to measure lesion scores, and the number of oocysts excreted (OPG) was determined per cage. Data were analyzed using the mixed model (SPSS). On the same day, cecal samples (n=8) were collected to quantify E. tenella (PCR), and to analyze the cecum status. These data were analyzed by ANOVA.
Infection reduced performance in IUC (BW d34: 2.48 vs 2.568 kg UUC; post-infection FCR: 1.52 vs 1.49; P<0.001). SAL showed the best performance (BW d34: 2.62 kg; FCR: 1.44), higher than UUC. AP2 improved performance compared with IUC (BW d34: 2.55 kg) and was statistically equivalent to UUC at trial end. Post-infection mortality was 1.8% with AP2, compared to 3.1% for UUC, 4.0% for IUC, and 2.7% for SAL. The European Production Index (EPI) was higher for SAL (520), UUC (517), and AP2 (497) than for IUC (477) (P=0.028). No effect of AP2 on OPG was observed, but a reduction in cecal lesions by E. tenella was noted with AP2 compared to IUC (P=0.08). Cecal analysis showed that infection increased IL-1β and IL-6 (P=0.046 and P=0.036), while SAL and AP2 partially reduced these levels. The expression of ZO-1, decreased in IUC (P=0.008), was partially restored by SAL and AP2. Finally, AP2 reduced E. tenella DNA by about 3 log (P<0.001), reaching an intermediate level between IUC and SAL/UUC. In conclusion, AP2 improved the growth of chickens infected with coccidia, with a tendency to reduce lesions and the impact of E. tenella on the cecum.