MASTERING COCCIDIOSIS: Cocci Clinic Series – Part 4

Conquering Resistance: Expert Strategies for Long-Term Control

Written by Zamira Australia

Optimal Coccidiosis Solutions for Your Farm

Choosing the right anticoccidials to manage coccidiosis on your farm can be challenging with so many options available. Your local Zamira technical service representative can help you find an effective system tailored to your needs. In this blog, we provide practical insights into using ionophores and chemicals for managing coccidiosis, along with expert strategies for long-term control and minimising anticoccidial resistance. It is important to remember that while anticoccidials are crucial in coccidiosis management, they can never replace the importance of good farm hygiene and biosecurity measures.

Golden Rules for Using Anticoccidials

When using anticoccidials, it’s essential to follow some golden rules to maximise their effectiveness. These principles are based on the categorisation of anticoccidials into chemicals and ionophores, with ionophores further divided into monovalent, monovalent glycosides, and divalent types. (For more background on anticoccidial types, please revisit Part 3 of our Cocci Clinic Series: Prevention or Treatment? The Ultimate Strategy Against Coccidiosis.)

  1. Rotate Anticoccidials Regularly: Avoid using the same anticoccidial for too long. Changing between different categories helps prevent resistance. Generally, one class of ionophores can be used for up to six months, while a type of chemical can be used for up to three months consecutively.
  2. Allow Adequate Rest Periods: After using an ionophore, avoid using another of the same class for at least six months. This rest period helps maintain the efficacy of the anticoccidial.
  3. Rotate Between Classes: For example, do not follow the use of one monovalent ionophore with another monovalent ionophore. Rotating between different classes of anticoccidials is critical for effective management.
  4. Annual Chemical Clean-Up: Conduct a chemical clean-up once a year to significantly reduce infection pressure. Chemical anticoccidials help decrease the shedding of oocysts on your farm, providing a reset and enhancing overall coccidiosis control.
Diagram: Four Golden Rules of Anticoccidial Use

Understanding the Difference Between Ionophores and Chemicals

Knowing the differences between ionophores and chemicals can help you decide which to use and when.

Immunity: Ionophores allow leakage of coccidia antigens into the chicken’s immune system, stimulating immunity development. In contrast, chemical anticoccidials do not trigger an immune response.

Resistance: Resistance to anticoccidials reduces the available tools for managing coccidiosis. Resistance to ionophores develops more slowly and is generally not permanent, whereas resistance to chemicals can occur quickly and may be permanent.


  • Ionophores: Can be used longer than chemicals and promote some immunity development.
  • Chemicals: Highly effective in controlling coccidia.


  • Chemicals: Resistance can develop quickly and may be permanent.
  • Ionophores: Resistance develops more slowly, but potential side effects (e.g., leg weakness) can occur if consumed in higher quantities than intended. The effects of ionophore toxicity are discussed further below.

Ionophore Toxicity

Dosage for Ionophores: Ionophores are approved for use in broiler feed at levels deemed both effective and safe for chickens. Since chickens self-regulate their feed intake based on their energy needs, feed consumption varies: higher energy content leads to lower feed intake, while lower energy content leads to higher feed intake. This variable dosage range offers flexibility and efficiency in poultry production.

Low-Grade Ionophore Toxicity: Leg weakness has been linked to low-grade ionophore toxicity, caused by factors such as higher inclusion levels in feed and increased feed intake by chickens. In broiler houses, aggressive chickens often eat first, leaving weaker ones to eat what remains. When feed pellets break down into crumbles or mash, these forms can contain higher concentrations of ionophores, leading to toxic symptoms like leg weakness.

Rotation & Shuttle Programs to Manage Resistance

Rotation and shuttle programs are essential for preventing resistance to anticoccidials, promoting better gut health and feed utilisation in birds. These programs involve alternating between two or more types of anticoccidial chemistries. Below is an example of different chemistries that can be alternated in these programs. The alternation does not need to follow a specific order and can include combination products.

Diagram: Dynamic Chemistry Rotation

Most rotation programs also incorporate a shuttle program, where a chemical anticoccidial is used in the grower feed. Below are examples of rotation and shuttle programs.

Diagram: Rotation Program example
Diagram: Shuttle Program example

Design Your Next Rotation and Shuttle Program with Zamira Australia

Leverage Zamira products and our technical experts to design your next rotation and shuttle program. The design of an effective anticoccidial program depends on:

  • Current anticoccidial efficacy on your farm
  • The current coccidiosis situation
  • Your existing anticoccidial program
  • The season

Zamira offers a wide range of products across various anticoccidial classes, perfect for your program. Our knowledgeable technical experts are ready to assist you in setting up a program that ensures long-term control and minimises anticoccidial resistance.

Zamira’s Range of Anticoccidial Products Spans Multiple Categories

Zamira’s ZamiCocci range includes products within the chemical, ionophore and combination classes. All Zamira products can be incorporated into your anticoccidial rotation and shuttle programs.

Revisit Part 1: Navigating Coccidiosis – Understanding the Life Cycle & Best Practices for Management

Part 1 of Zamira’s Cocci Clinic Series takes you on a journey through the life cycle of this persistent pathogen, equipping you with the best practices for effective management.

Revisit Part 2: Decoding Coccidia – Spot the Tell-Tale Signs & Navigate Diagnosis for your Farm

In Part 2 of Zamira’s Cocci Clinic Series, we focus on the tell-tale signs of coccidiosis and show you how to navigate diagnosis for your farm.

Revisit Part 3: Prevention or Treatment? The Ultimate Strategy Against Coccidiosis

In Part 3 of Zamira’s Cocci Clinic Series, we explore the ultimate strategy against this relentless pathogen. From understanding the infection to expert tips on long-term control and minimising resistance, Zamira has you covered!

Zamira is an Australian animal health company with a mission to improve the health, wellbeing and productivity of animals through prevention, detection and treatment . Read more about us here.

How can we help you?

Want to find out more about how to prevent and control coccidiosis in your flock? Zamira Australia has teams in Australia, South East Asia and South Asia who can work with you on a tailored solution to meet your needs. Fill out the form below and we’ll get in touch with you shortly.

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