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Expert Talks: Dr Jean-Michel Répérant on Coccidiosis in Poultry

For this serie of “Expert Talks” we were pleased to welcome Dr Jean-Michel Répérant to the round table discussion, in a panel with Vaxxinova colleagues from Brazil, Jordan, the Netherlands and Thailand. The topic: Coccidiosis in poultry.

Dr Jean-Michel Répérant is Doctor in parasitology. He heads the avian parasitology team at Ploufragran research laboratory (part of Anses) in Brittany, France.
Already since 1996 his research at Anses focuses on avian parasites, especially coccidia of the genus Eimeria.

From this wealth of experience we were allowed to gather further insights and knowledge on the topic of coccidiosis.

And here is the final and concluding message when it comes to coccidiosis in chickens. Coccidia are much more complex then we suspect. Many aspects are still to be discovered and understood. But, coccidia are very interesting organisms.
Thank you to the Experts; Dr. Jean-Michel Répérant and the Vaxxinova colleagues for contributing to this series of Expert Talks: coccidiosis in poultry.

What is the effect on the health of chickens when they are challenged with mycotoxins in the feed and at the same time have received a coccidiosis vaccination? Same question applies to the use of anticoccidials. Is there a clear answer? Watch the insights as shared in this video.

Why are Eimeria tenella and Eimeria necatrix different from the other Eimeria species?
Eimeria tenella and Eimeria necatrix can kill the bird, because they have different characteristics compared to the other Eimeria species. This relates to their origin and to their lifecycle. A very interesting discussion with Vaxxinova colleagues and Dr. JM Répérant.

Is it coccidiosis? Or a bacterial problem? How can we tell the difference?
If we do not find typical lesions of coccidia, we can be sure it is not coccidiosis. But how to determine what causes the problem? There are some tools, as Dr JM Répérant points out in this video.

Is it effective to vaccinate birds twice against coccidiosis?
Besides being expensive, the question is how useful will re-vaccination be?
Expert Dr JM Répérant discusses with Dr Ludio Gomes (Vaxxinova) why he consideres re-vaccination not to be efficient.

It is not easy to asses whether or not a vaccination against coccidiosis has been successful. However, there are some tools and methods to determine the effect of the vaccination. Dr JM Répérant explains in this video.

Vaxxinova colleagues discuss with expert Dr JM Répérant the relevancy of oocyst counting. Oocyst counting is not a good tool for diagnosis of coccidiosis. But it is a very interesting tool to monitor coccidiosis vaccine intake. The video explains how to apply this method and what to consider.

When birds are properly immunized, either by vaccination or otherwise, it is still possible that coccidiosis occurs. How come? In an interesting conversation Expert Dr JM Répérant and Vaxxinova colleagues Gustavo Schaefer (Brazil) and Marcelo Zuanaze (International) shed some light on this topic.

Dr Répérant explains why it is possbile to see coccidiosis in long living birds at any age. Usually it will not happen in the first week of life, but the challenge can be there till the end of the lifetime.

Does the presence of 7 species of Eimeria’s in the vaccine cause interference between them?
Dr JM Répérant in conversation with Vaxxinova’s Dr Sandra Fernandez. The expert’s view on the effect on immunity and protection when all seven Eimeria species are available in the vaccine.

What is the best age to vaccinate birds against coccidiosis?
Dr JM Répérant explains why it is important to vaccinate birds as early as possible; in hatchery or up to maximum 3 days of age.

Will a post-vaccination reaction occur after using a coccidiosis vaccine in poultry?
In general, no abnormal development or observation will occur after vaccination. Dr JM Répérant explains to Dr Gustavo Schaefer what is likely to happen after vaccination of birds with a coccidiosis vaccine.

Listen Dr JM Répérant explaining to Dr Ludio Gomes why he believes that precosious attenuated vaccine strains will not return to virulence.

A view on the pros and cons of when best to apply virulent or attenuated coccidiosis vaccines in poultry. Looking at regional differences and preferences, production questions, safety and the risk of spreading eimeria species.

It is hard to kill the eimeria parasites. But, do we actually need to kill them? Eimerias are very resistent and the oocysts are strong. It is more important to keep the balance between the parasite and the chicken. To keep the chicken healthy, with good growth and good FCR.

Dr Jean-Michel Répérant and Vaxxinova Brazil’s Dr Gustavo Schaefer discuss the reason why macroscopic lesion scoring is a relevant tool in diagnosing coccidiosis. There is no evolution of lesion score in a single bird. Therefor, scoring of five birds in a flock will provide a good insight of the coccidiosis status of the whole flock.

In this lively discussion Dr JM Répérant and Dr Ludio Gomes discuss the signs that point to 𝘌𝘪𝘮𝘦𝘳𝘪𝘢 𝘮𝘢𝘹𝘪𝘮𝘢. Especially the presence of orange mucus, in relation to 𝘌𝘪𝘮𝘦𝘳𝘪𝘢 𝘮𝘢𝘹𝘪𝘮𝘢. Or does this indicate other issues are playing a role? And are there regional differences to observe? Watch the video to find out more.

Do we still have to worry about cocidiois, if we cannot see macroscopic lesions? The answer is a clear “no”, as explained in this video.

What is the best tool to monitor coccidiosis in long-living birds?
The answer depends on whether you want to monitor clinical/subclinical coccidiosis or want to determine the coccidiosis pressure present. For the latter, the OPG analysis (oocysts per gram faeces) is a valid method.
Dr JM Répérant and Vaxxinova’s Dr Ludio Gomes explain why.


The topic of lesion scoring continues. Some 𝘌𝘪𝘮𝘦𝘳𝘪𝘢 species do not show clear clinical signs, like 𝘌𝘪𝘮𝘦𝘳𝘪𝘢 𝘱𝘳𝘢𝘦𝘤𝘰𝘹 and 𝘌𝘪𝘮𝘦𝘳𝘪𝘢 𝘮𝘪𝘵𝘪𝘴. Is it still possible to monitor these species? Expert Talks, with Dr JM Répérant and Vaxxinova colleague Dr Sandra Fernandez, provides insight.

As a follow up from the previous episode of Expert Talks, related to macroscopic lesion scoring, this video continues on how to “read’ the scoring and how to relate this to treatment of the birds. Dr JM Répérant and Vaxxinova colleague Dr Ludio Gomes explain.

Dr JM Répérant and Vaxxinova colleague Dr Husam Bakri discuss when it is useful to apply macroscopic lesion scoring when there is a suspicion of coccidiosis in the flock. However, there are some challenges related to perform this well. This Expert Talks episode goes deeper into the topic.

In this Expert Talks video, Dr JM Répérant provides insight in what could be the best diagnostic techniques to establish coccidiosis in chickens. It is important to differentiate between clinical and subclinical coccidiosis. And it will be hard to find coccidiosis in the laboratory when only subclinical coccidiosis is suspected. Why? Watch this video to find out.

Do we have to worry about eimeria variants? As is often the case, this questioned cannot be answered straigth forward with yes or no! For the answers, listen to Dr Répérant and the Vaxxinova colleague in this Expert Talks video.

What is the real impact of both clinical and subclinical infections on performance?

This video will explain why the most important economical impact is caused by subclinical infection – although this is not always directly visible in the bird.

Coccidiosis in poultry; Expert Talks with JM Répérant

Meet the participants who will be starring in the series of videos on the topic of coccidiosis in poultry.