PSVIII-3 Beneficial effect of cashew nutshell liquid-based supplements in vaccinated broilers against coccidiosis

Abstract

Abstract Vaccination has been developed over the years to counter coccidiosis; however, its effectiveness varies, and it is difficult to exploit due in particular to the young age of chickens at slaughter. Cashew nutsell liquid (CNSL) supplements have shown beneficial effects on growth performance and anticoccidial effects in Eimeria-challenged broilers. However, CNSL effects during an Eimeria infection in vaccinated chickens against coccidiosis need to be determined especially for organic production. Broilers vaccinated against coccidiosis were housed in pens and received one of the following treatments: 1) non-infected, non-treated (blank control); 2) infected, non-treated (negative control); 3) infected, nibarbazin/monensin shuttle program (positive control); 4) infected, Calica+ (CNSL-based formulation). Eimeria infection was induced by an oral administration of 200,000 sporulated oocysts of mixed Eimeria species harvested from field isolates. The trial was performed with 8 pens of 45 birds per treatment. Performance data and oocyst counts were analyzed by a mixed model including treatment as fixed effect and pen as random effect. Intestinal lesion scores were analyzed by category analyses. Calica+ improved average daily gain (ADG) (+7.4%, P < 0.05) and showed a trend to reduce feed conversion ratio (FCR) (−1.8%, P < 0.07) during the overall growing period (days 0–35), compared to infected and untreated broilers. Birds fed Calica+ also showed higher ADG than birds on nibarbazin/monensin shuttle program (+7.2%, P < 0.05). Calica+ did not change levels of oocysts per gram of feces (OPG) at Eimeria excretion peak (6 days after inoculation) but it showed a trend to reduce the Eimeria tenella intestinal lesion scores (p< 0.0685). In summary, the CNSL-based formulation Calica+ showed beneficial growth performance and anticoccidial effects in vaccination conditions against coccidiosis. This organic feed additive could be involved in an anticoccidiosis strategy that includes vaccination.