With a mortality rate of up to 30 percent, blackhead disease can be detrimental to the flock and to poultry producers. Dr. Robert Beckstead's team at North Carolina State University is researching on the disease on a molecular level. Are there alternative treatments and preventatives to consider? Dr. Beckstead shares why producers may reconsider their feeding strategy in the future.
The following is an edited transcript of Kara Keeton's interview with Dr. Robert Beckstead. Click below to hear the full audio:
Kara: I'm here today with Robert Beckstead, associate professor of poultry science at North Carolina State University. Thank you for joining me today.
Robert: It's a pleasure to be here.
Kara: Now, I understand that your area of specialty is molecular diagnostics of poultry. Tell me a little bit more about that field.
Robert: Molecular biology is really just looking at DNA, RNA or protein and, then, it's using those markers or biological molecules to be able to diagnose diseases. For instance, each species has a very specific genetic makeup, and so, we can use that to detect those species.
Kara: So, you're able to look at major concerns and health issues facing the poultry industry?
Robert: We use these as part of our toolkit to be able to study parasites, as well as other pathogens — sometimes, just knowing whether the organism is there, then you can correlate that with the diseases that you see.
Kara: What are some of the biggest diseases facing the poultry industry today?
Robert: Some of the biggest diseases facing the poultry industry would be viral diseases that cause problems with the health of the bird, but most people are concerned with bacterial diseases that also have a human health implication. My lab studies “the ugly stepsister,” which are the parasites that are associated with diseases in poultry, and although those parasites don’t cause diseases in humans, they can cause a huge financial risk to the poultry industry.
Kara: And one of these diseases that I have read that's a major concern these days is blackhead disease. What exactly is that disease and how does it impact the bird?
Robert: Blackhead disease — or histomoniasis — is caused by a single-cell, anaerobic protozoan parasite called Histomonas meleagridis. In chickens, it can cause up to 30% mortality and increased morbidity, especially in layers or breeders, where it can cause reduced egg production, as well as decrease in the first lay. In turkeys, though, it's quite catastrophic; turkey flocks with an outbreak of histomoniasis can lose 100% of the birds.
Kara: Which is devastating to a farmer, of course.
Robert: Yes, it is, and part of the problem that goes along with it is that all the treatments and preventatives for this disease have been taken off the market. So, in reality, when a turkey flock breaks out with blackhead disease, all that the grower and company can do is wait to see how many birds are going to die.
Kara: Your research has been to study this disease and possible alternatives to treating it. Is that correct?
Robert: That is correct.
Kara: What have you discovered in your research?
Robert: Our research focuses on probably four different areas: First is looking at the genetics of the bird. We've started screens to look for subpopulations of turkeys that may be resistant to the disease, and so, the idea is that maybe we can breed a healthier bird, and that bird will then be resistant to the organism.
The second area that we've looked at is looking for alternative treatments. There's a lot of what you would call “complementary” and “alternative” medicine out there — products that companies are producing to increase the health of the bird or that may have antiprotozoal activity. Our lab is set up to screen a number of these products to be able to see whether or not they can improve the outcome for birds that have been infected with this parasite.
Kara: What is the success rate found with these screenings?
Robert: The success rate for molecules or complementary medicine is zero in the bird. What we've noticed when we started to screen a lot of these molecules is that actually looking at how molecules affect the disease isn't just a matter of whether or not they get rid of the parasite. The research in my lab has begun to focus on how the organism is transmitted bird-to-bird. What we've identified is that birds that are healthy have a tendency to block the transmission of the disease. So, even though the organism may get into a flock, if birds aren't flushing or birds don’t have other enteric problems or gut health problems, then, actually, the transmission of the disease is slow, and you will have fewer birds that will die from the disease.
That's changed, in a way, how we are starting to look at products, whereas before, we looked at products to say, "Is this antiprotozoal?" Now, we look at products and say, "Okay. What is this actually doing to the overall health of the bird, and can we measure that in terms of its ability to block that transmission of the parasite?"
Kara: This is where feed and nutrition really come in to play a role in this whole research and development of alternative ways to address this disease.
Robert: That is correct. Really, it's opening up the doors to be able to look at alternative products and ask the question of whether or not they are improving the health of the bird. At the same time, what we've noticed is that other pathogens can also cause the bird to be ill and that, then, sets the bird up for transmission of the disease. So, if we find a product that improves the health of the bird because it reduces some of the bacterial load that's associated with the bacterial pathogens, that actually can have a positive effect on the disease that we're studying — blackhead disease — because a healthier bird isn't going to have less transmission of the disease.
Kara: Are there any technological advances that you're able to use in your research that have really helped move this forward as you're studying bird health and gut health?
Robert: The disease that I study begins in the ceca. The ceca is a pouch that's part of the intestinal system, where fermentation occurs in the bird. In most cases, nutritionists or scientists or growers really don’t care about the ceca because it doesn’t play a role in feed conversion as much. It doesn’t play a role much in weight gain and it's at the end of the digestive tract. The problem is that's where Histomonas resides. Salmonella, E. coli, campylobacter — all these organisms are living in the ceca and, in a sense, we're not as worried about it.
The new technology that we're pushing — and, also, that my lab is working on — is: How do we encapsulate some of these products, which, as we've shown in an in-vitro system, can have antiprotozoal or antimicrobial activity and get them to the ceca? So, in order for them to not be digested, absorbed, changed in some way through the microbial community, we need to deliver them to the ceca so that they can have that activity in the location where it's needed.
Kara: Where do you hope to see the research develop in the next few years and developing ways to address these problems and maybe move towards new solutions for these diseases?
Robert: I'll give you this as a caveat because I'm a parasitologist, but I really think that, as we begin to lose more of the drugs and treatments that we currently have, we're going to have to actually develop new strategies, and those strategies are really going to be a focus on bird health. Currently — and this is a broad stroke — diets are designed based on feed conversion ratio and how much it's going to make the bird gain weight. That's how we make our money and that's how we keep our product cheap or affordable, but, in the future, we may have to start to design diets primarily on health and then, secondarily, look at, “How does this affect feed conversion? How does this affect weight gain in the bird?” That actually opens up a large research area to say, “How is it that we test a product to determine whether or not it actually is improving the health of the bird or is causing problems?”
I'll give you an example: We've tested some essential oils and, at lower levels, we see some good effects in terms of the health of the bird — but if we increase those levels, it causes some damage to the gut, and now, the bird begins to flush, and now, we start to see increased transmission rates of blackhead disease. So where, on one condition, that product may actually be useful, but where more product may actually cause a problem for the bird — and so, we need to be able to look at each product as we would if we were trying to get FDA regulation and actually really understand how that product is helping the bird and in what condition.
Kara: It looks like you still have a long road ahead as you continue to explore other avenues for addressing these issues with the reduction in antibiotics and drugs in the industry, but I think you're making some progress with some of the developments.
Robert: Yeah. I'm excited for the research moving forward. I think it is going to, in a sense, in the future, revolutionize how we grow chickens and actually make ourselves better — both for the chicken itself but also better for the consumer and better for the environment.
I also think some of the research is occurring now because, in the poultry industry — well, in animal agriculture — we're being forced to find alternatives, but these alternatives in the future will actually make it back into human medicine. And so, the stuff that we're learning right now, in terms of understanding how we can treat a bird without using antibiotics, maybe, in the future, will help us understand how we can treat a human without the use of antibiotics and be able to reduce antibiotic use across the board, not just in animal agriculture.
Kara: That sounds wonderful. Thank you for joining me today, Dr. Beckstead, and I hope you enjoy your day.
Robert: Thank you.
Kara: That was Dr. Robert Beckstead, associate professor for poultry science at North Carolina State University.
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