14 May 2025

6 minute read

By: Sarah Mikesell

Europe

North America

Dr. Alistair Thomas, the Global Head of Poultry Nutrition and Health at Anitox, spoke to The Poultry Site’s Sarah Mikesell about on-farm biosecurity for avian influenza. Dr. Thomas is a microbiologist and leads a team of technical experts who operate across 68 countries and provide scientific support and feed additive solutions to customers and partners.

Editor’s note: This interview has been edited for length and clarity.

What are you hearing about avian influenza from your global team?

Unfortunately, it remains a hot topic internationally with varying levels of infection, but there's very few regions where poultry are raised and wild birds exist where you cannot get the disease. The biggest challenge for producers and veterinarians during the winter, especially here in the US, has been that there are other significant diseases present. We also have avian metapneumovirus and infectious laryngotracheitis (ILT), which have become a big issue all at once.

What's emerging over the last 12 months is the prevalence of avian influenza in dairy herds as well. That has made the public a bit more worried, and obviously it's got the producers worried. There's no human-to-human transmission yet, but that's another source of the infection which has a lot of people concerned.

What biosecurity best practices do you recommend?

Experience is the best learning for a lot of things. We’ve had challenges, particularly in 2022 with some of the major breaks, and we know that biosecurity is by far the best way to manage and mitigate this disease. But you're not going to eliminate it completely.

I have seen growers that have been successful, even when they've been next to very localized outbreaks and have been in those control zones. It’s by not just having a biosecurity protocol but having one that you're trained on and can access easily, and that you're very fastidiously managing.

Ironically, when I've spoken to veterinarians, they've found that in areas where there have been outbreaks of AI, their Salmonella has been reduced significantly as well. The whole level of biosecurity and attention to that kind of detail really makes a difference across the board, not just for avian influenza, but for other disease issues that might be in the poultry house.

Specifically for feed, what can producers do?

There's actually very little research available for poultry on how viral contamination can occur through the feed. What I'm seeing from my swine counterparts is there's certainly a strong correlation between feed as a potential vector for things like PRRS and African swine flu virus. I think that there's a capability of feed always to be a vector. Is it the biggest one for some of these viral challenges in poultry? Probably not, but a strong biosecurity protocol and attention to all those potential points of ingress (entry) for a virus will only benefit the producer going forward.

It's important to note that if you've got good biosecurity protocols, you're going to reduce your bacterial challenge. We know it is a problem in animal feed – specifically corn, soybean meal, and meat and bone meal. All those ingredients that go into the poultry diet have been very well indicated in research to be vectors for bacterial contamination, for things like Salmonella, Clostridium, etc. Hopefully controlling those feed stuffs as potential vectors will minimize the risk of getting bacteria or disease challenges in your poultry houses.

Why is feed biosecurity so important?

Producers can start by understanding what's in their feed and in their raw ingredients. When we see the biological analysis of the feed ingredients and the final feed, it will give you an indication of where your baseline is for some of these pathogens. It's not going to be a high microbial burden in every single sample, but you need to understand and risk assess where your potential points of challenge or contamination are.

Once you've done that, there’s a mitigation step that we can put in place to reduce the chance of that becoming an issue later in the bird and hopefully never to reach the consumer. By reducing the bacterial challenge upfront, it allows you to minimize the risk of contamination. We've seen the knock-on effects of overall bird health. Gut health development is helped by reducing some of these pathogenic factors in the feed.

How important is continual testing for feed biosecurity?

We're incredibly lucky here in the US where we have local corn and soybean meal, so there's not as much of an issue with contamination and long-term storage of these feed grains. In regions outside the US, where feed and feed ingredients are shipped internationally and must travel long distances at elevated temperatures, there's certainly a much higher risk of bacterial and fungal contamination being a problem.

It's certainly important to test and understand where your baseline is. You're not going to have completely sterile feed in any situation, but you need to know when you've got a consistent level that's managed well and that is not posing a negative impact on the birds or human health. Then, understanding when that goes out of control and what interventions to put in play will hopefully bring that well within control limits for your relevant production process.

If you do have a problem, what feed solutions that are available to producers?

Traditionally by pelleting feed, the heat treatment of feed under pressure has been how feed mills have managed microbial contamination. Research has shown that it’s not completely infallible, and you still get some contamination that moves through the process, even down to re-contamination within the feed mill.

Employing feed hygiene measures using chemical applications, like formaldehyde, essential oils or organic acids can also help. All those mitigants can be put into the feed or sprayed on in the feed mill. Not only do they keep your feed mill lines better bio-controlled, but they also allow the feed to have a reduction in microbial load.

Then, when the feed gets to the chick in those early sensitive days when its microbial development is just starting in the gut – it is not fully there and the immune system is relatively naive, the mother's antibodies are reducing – you don't want a higher risk of disease issues by having some contaminated feed. Using those interventions at the feed mill and in the feed will allow you to keep a cleaner feed mill and feed that will produce the healthiest bird.

How important is effective communication with your feed mill when it comes to feed biosecurity?

No two feed mills are the same, either in structure, design or management which makes it a bit of a challenge when you're trying to understand where potential contamination points are.

In the industry, we realize that the feed mill is not just a cost center. It can have some positive impacts on the poultry performance. With minor modifications, support and a real understanding of feed mill challenges, it can reap benefits further down the production process for the grow-out of birds and even through processing.

When I’ve seen really effective biosecurity protocols and producers in hot AI areas, for example, that have not broken with the disease, it’s because of effective communication. It's when you've got communication between the feed mill, veterinarians, live production managers and nutritionists. When we can take down the silos in the production process, that is going to reap the benefits for a safer environment for the bird.

The challenges come when there's a lack of communication sometimes. It is not intentional. Everybody wants to grow a healthy productive bird, but sometimes real life gets in the way. Certainly, communication needs to be especially effective when you have to have a rapid response to some of these disease challenges like avian influenza and others we see in current production.