Decoquinate is administered to poultry primarily to control which of the following?

Decoquinate is primarily used in poultry to control coccidia, which are protozoan parasites that can cause significant health issues, including coccidiosis. This condition is particularly problematic in young birds, where it can lead to poor growth, diarrhea, and even mortality. Decoquinate works by inhibiting the development of coccidia in the intestinal cells of the host, thus preventing infection and allowing for healthier growth and development of the poultry.

The other options pertain to different types of parasites that require specific treatments. Roundworms, tapeworms, and flukes are helminths (worms) that necessitate different anthelmintic medications for effective management. They are not controlled by decoquinate, which specifically targets the life cycle of coccidia. Understanding the different classes of parasites and the specific medications used to manage them is crucial for effective veterinary practice in poultry health.