LAUSR

SUMMARY Avian coccidiosis is an important parasitic disease of birds, caused by genus Eimeria, and having great economic importance. The estimated global economic loss due to coccidiosis is up to US$3 billion annually. Approximately 80% of these losses are associated with performance parameters, including decreased weight gain, heavy mortality, poor feed conversion ratio and the remaining 20% of losses include the cost of prophylaxis and treatment measures. This disease has been controlled by different anticoccidial agents, but synthetic drug-resistance is the major issue due to which researchers are trying to develop modern alternate effective approaches. Moreover, drug residues cause health hazard issues for poultry product consumers, which have led to the cessation of such practices in developed countries. Control through vaccination can be considered as a good practice, but due to the high cost and complexity of Eimeria species, development of a cost-effective vaccine has proved challenging. Among other options, probiotics have shown favourable effects against coccidiosis. Use of probiotics can reduce 70–80% of losses faced by the poultry industry worldwide. They have shown excellent results due to their antioxidant, immunostimulatory and positive effects on intestinal health of infected birds. Furthermore, details about the expression of the host biological responses against poultry coccidiosis and how probiotic supplementation assists in improving these responses in chickens are described in this review.