Rotation for results

Coccidiostats have been commercially available for a long time meaning the parasite has had the opportunity to adapt and develop resistance. The reason for rotation is to avoid this development of resistance as much as possible. With no new molecules coming onto the market in the near future, we need to take care of the coccidiostats we have and use them wisely. Over usage of one product will always lead to reduced efficacy, as the following cases demonstrate.

A large European poultry integrator used the same combination product (nicarbazin/narasin) for more than four consecutive years. The ionophore which was used following the combination product was changed three times per year (narasin, salinomycin and monensin). The producers believed that there was no need to change to the new combination product (Monimax®, nicarbazin/monensin) as they didn't experience any critical issues in the field.

To demonstrate the possible danger of such practice, Huvepharma took field samples in 2020 and again in 2024. Both samples were used in an AST (anticoccidial sensitivity trial) and the combination product was tested on both occasions. Compared to the infected, untreated control (IUC) group, the performance improvement in 2020 was 35% which is considered as effective (Figure 1). The improvement in 2024 on the other hand was only 13% which is considered as bringing little benefit. In 4 years, the effectiveness of the combination product had reduced by more than half. Following the latest trial, the company decided to switch to Monimax® and rotate between another combination product which was also giving them significant improvements in the field.

Figure 1. AST performance results from samples taken in 2020 (left) and 2024 (right)

A second example of the benefits of rotation comes from field data generated by another European poultry producer. Prior to the trial there were not many rotations. In the summer of 2022, the producer decided to do a chemical break with Stenorol. Figure 2 shows the evolution of the European production efficiency factor (EPEF) before, during and after the chemical break. Before the break, the nicarbazin/narasin combination product was used in the starter diet. After the break, Monimax® (nicarbazin/monensin) was used in the starter diet. The graph clearly shows the benefit this chemical break brought to the company. For the first time they were able to reach an EPEF of more than 400. 

Figure 2. Evolution of the European production efficiency factor (EPEF) from early 2021 to the end of 2022

Figures 3 and 4 show the improvement in EPEF was mainly driven by a lower feed conversion rate (FCR), although the growth was also positively influenced by the chemical break and rotation to Monimax®.

Figure 3. Evolution of adjusted weight from early 2021 to the end of 2022

Figure 4. Evolution of adjusted FCR from early 2021 to the end of 2022

In summary, these two examples clearly demonstrate the benefit of rotating between coccidiostats. Even when problems in the field are not obvious, not doing a rotation will have an impact on performance. This is why the visual of an iceberg is used when talking about coccidiosis. The problem is quite often not visible to the producer, making it more difficult to make the right decisions. In the end, it is common sense and easy to understand that overusing one product will always lead to reduced sensitivity. This is not only the case for coccidiosis control products, but for any kind of disease control measures.

All data shown in this article was gathered using Aviapp®, the poultry performance platform from Huvepharma.