Nutrition and health interactions: Coccidiosis challenges and vaccination

DR. SAMUEL J. ROCHELL, UNIVERSITY OF ARKANSAS, USA

During his presentation at the Huvepharma® seminar, Dr. Rochell explained the importance of understanding nutrient utilization in poultry production, especially during subclinical coccidiosis challenges. Dr. Rochell revealed that lipid digestibility decreased more significantly compared to other nutrients during a coccidiosis challenge.

Coccidiosis continues to be one of the most pervasive and economically detrimental diseases in commercial poultry production. Controlling this enteric disease is an even greater challenge for poultry producers adopting production systems in which ionophore anticoccidial drugs are excluded to meet customer specifications for reduced or no antibiotic use products (e.g., no antibiotics ever, raised without antibiotics, etc.).

Chemical anticoccidial drugs are prone to resistance and can become ineffective, leaving live Eimeria vaccines as an increasingly important coccidiosis management tool. However, naturally occurring or vaccine-induced subclinical coccidiosis is not only damaging to nutrient utilization and performance, but it can also predispose broilers to necrotic enteritis, an enteric disease associated with proliferation of Clostridium perfringens. As such, a better understanding of nutrient utilization during periods of subclinical coccidiosis should reveal strategies to support bird performance and minimize availability of nutrients to Clostridium in the lower gastrointestinal tract.

Recent work in our laboratory has aimed to characterize the impact of coccidiosis on nutrient utilization in broilers and has revealed that lipid digestibility is impacted to a greater magnitude and duration compared with digestibility of other nutrients. In a subsequent experiment, increasing the concentration of supplemental lipid to compensate for this malabsorption was detrimental to feed conversion in coccidiosis vaccinated birds. Impaired lipid digestibility will certainly reduce absorption of fat-soluble vitamins, including vitamin D, which will in turn influence calcium and phosphorus absorption, and excess calcium has been suggested to be a predisposing dietary factor for necrotic enteritis. Ongoing research in our laboratory is investigating mechanisms of impaired lipid utilization during coccidiosis and practical nutrition strategies that may ameliorate these effects.