Authors. Ronsmans, S.; Van Erum, J.; Dardi, M.

Coccidiosis still is one of the most costly diseases in modern broiler production. The most important reason for this financial loss is an increased feed conversion ratio (FCR) and a decreased weight gain (Williams, 1999), which is even more pronounced when feed costs are high. Additionally, clinical disease - in broilers mainly caused by Eimeria tenella - will lead to increased mortality. Coccidiosis is also one of the most important predisposing factors for bacterial enteritis (dysbacteriosis and/or necrotic enteritis), which adds to the total damage (Timbermont et al., 2011).

Popular belief in the modern broiler industry still says that it is hard to get similar zootechnical results when preventing coccidiosis by vaccination, compared to using anticoccidial feed additives. However, the data above show that there are no significant differences in ADG, BW, FCR and EPEF between the cycles produced with anticoccidial drugs (preceding coccidiosis vaccination) and the cycles produced while using a coccidiosis vaccine.