Feedstuffs in Focus
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Feedstuffs in Focus
Ileitis treatment options and resulting correlation on average daily gain
Ileitis is a common cause of diarrhea in grow-finish pigs. When underdiagnosed, ileitis can result in a significant amount of money being left on the table and out of producers’ pockets.
Joining our Ann Hess today to talk about ileitis and what producers can do to minimize its impact is Dr. Nate Winkelman, co-owner and veterinarian at Swine Services Unlimited.
This episode is brought to you by Pharmgate Animal Health, a growing business that puts livestock first. Pharmgate provides a proven portfolio of technically supported, high-quality products that are the foundation of custom herd health protocols. By offering multiple options for active ingredients, concentrations, and administration routes, Pharmgate provides you with choices to fit your needs and gets you the results you want.
Iliitis is a common cause of diarrhea in grow-finish pigs. When underdiagnosed, iliitis can result in a significant amount of money being left on the table and out of producers' pockets. Welcome to Feedstuffs in Focus, our podcast taking a look at the big issues affecting the livestock, poultry grain and animal feed industries. I'm your host, sarah Muirhead. This episode is brought to you by Farmgate Animal Health, a growing business that puts livestock first. Farmgate provides a proven portfolio of technically supported, high-quality products that are the foundation of custom herd health protocols. By offering multiple options for active ingredients, concentrations and administration routes, farmgate provides you with choices to fit your needs and get you the results that you want. Joining our Ann Hess on this episode of Feedstuffs in Focus to talk about ileitis and what producers can do to minimize its impact is Dr Nate Winkleman, co -owner and veterinarian at Swine Services Unlimited.
Speaker 2:Dr Winkleman, let's start by having you tell us more about your role, your company and the research you do there.
Speaker 3:Thank you for the opportunity. My company is called Swine Services Unlimited Inc. I'm a co-owner with Dr Adam Mueller. It's a consultation and research practice. So we consult with progressive pork producers, mostly in Minnesota and Iowa, a little bit in the Dakotas, some international work. But our primary focus is doing research with swine diseases for vaccine and pharmaceutical companies and some just nutraceutical studies as well. We research all swine diseases Since about mid-95, I've developed a mucosal homogenate Lassoni intracellularis challenge model that was recognized pivotal for the FDA to approve antibiotics. So I've been still focusing on Lassoni intracellularis and continue that work.
Speaker 2:And today we're talking about Lassoni intracellularis, more commonly known as ileitis. How much of a problem does this pose for producers today?
Speaker 3:It's a considerable problem. Ileitis is endemic in pigs in North America. It's still considered the most common cause of grow finish diarrhea. In North America it's one of the two most common endemic bacteria, along with mycoplasma and the grow finish pigs. I think it's a lot of money still left on the table because subclinical and clinical ileitis is underdiagnosed and undertreated. Diagnosed and undertreated Daryl Holdkamp did a really good literature review a few years ago showing the cost of both subclinical and clinical ileitis to be anywhere from $6 to $16 per pig if it's identified in your system. So it's a very significant and common enteric problem in North America.
Speaker 2:Yeah, 6 to 16, that's quite significant. You recently shared new research at the American Association of Swine Veterinarians Conference in San Francisco on ileitis and finishing pigs. Can you explain more about that study and the top level findings?
Speaker 3:Yeah, it was a fun study for me for lots of reasons. I had a student intern that wrapped his arms around it, so I'm turning him into a pig diarrhea expert as well. I hope someday pig diarrhea expert as well. I hope someday. That's my goal. But it's unique in that it was. I've tested both lincomycin and avilacin, or tilvalocin or tilvalocin however you want to pronounce it many times individually, both in the feed and the water, and lincol has an injectable as well. But this is the first time I had the opportunity to test both of them side by side in an ileitis challenge model and this was in older pigs. It was in a 10-week-old pig when we challenged the pig and the trial lasted for 35 days. So it was a 10 to a 15-week-old pig. So it was a 10 to a 15-week-old pig. The trial design basically is we had three treatment groups. We had 170 pigs total. The challenge control group there were 50 pigs in the challenge control group that received a very high. All the pigs received a high 10 to the 10th Lawsonia challenge. The second group was the Abelson group. There are 60 pigs in the Abelson group. The third group was the lincomycin water medicated group. That had 60 pigs in it, also the pigs.
Speaker 3:We waited until we saw clinical signs but because of the very long incubation period of a Lawsonia to cellularis we didn't see clinical signs. We saw on day 13 post-challenge. 10% of the pigs had clinical signs. So that's when we started the five-day treatment. Pigs were treated from day 13 to day 18. We measured many parameters. We measured clinical parameters of fecal diarrhea scores, fecal color scores, body condition or abdominal appearance scores. Obviously we measured performance parameters of average daily gain, average daily feed intake and feed conversion rate. It was a terminal study. So 35 days after the pigs were challenged with Lawsonia, all the pigs were euthanized and we measured gross PPE or PIA as porcine intestinal adenomatosis. That's the underlying lesion of ileitis. You can actually see that grossly on the intestine. We measured a severity index on day 35 when we euthanized all the pigs. At the end, basically, under the constraints of this trial, ablac or tibulocin performed better in all the parameters that we measured compared to lincomycin. However, both of the antibiotics were effective in controlling the disease compared to the controls. So that's the bottom line summary.
Speaker 2:So what results did you see for ablison having on average daily gain and feed conversion rate, and how did that compare to the control or other treatments?
Speaker 3:The performance parameters. That's where you get into the economics and that's really what we measure. So I'm going to back up just one second and say that the challenge was a very effective challenge and it's difficult to challenge pigs that are. The older the pig is, the more bacteria you have to give, because the pig has an amazing ability to hide this disease. Diarrhea is not a common clinical sign by the time you see diarrhea in ileitis-challenged pigs. All the pigs are subclinically affected and some are clinically affected. This was a good challenge because we had mortality from ileitis in the grower pig. Two pigs died in the control group, one from acute PHE or porcine hemorrhagic enteropathy on day 18, and then one chronic pig died on day 28 in the control group. One pig died from the PHE acute bloody form of biliitis on day 22 in the lancomyosin group and there was not any mortality in the ableson group. To answer your question on average daily gain, there was just dramatic differences between the treatments and the controls the control group. When we measure average daily gain from day 13, when we started treatment until day 35 at the end of the study, the average daily gain in the control was 1.75 pounds per day and in tilvalocin it was 2.26. So that's almost 50 points. That's amazing. Lincomycin was at 2.07, and both lincomycin and the tilvalocin were statistically significant compared to the controls for average daily gain.
Speaker 3:Feed conversion is also an important parameter. This intestinal disease causes a hyperplasia or a thickening of the mucosa of the small intestine. So you can't normally assimilate nutrients. So both they go off feed. So average daily gain is affected. But the feed conversion rate is also significantly affected. In this trial it was a dramatic difference as well. The Avilacin group had a 1.81 feed conversion rate compared to a 2.69 feed conversion rate over that day 13 to 35-day period. The lincomycin group was intermediate. It had a 2.16 feed conversion rate. It wasn't statistically significant at a PO5 level for this study. It probably would have been if we would have had more than 60 pigs, because the differences were still quite high numerically.
Speaker 3:And then, lastly, I might as well mention the PPE severity score differences also. We look at the ilium first, the jejunum, the cecum and the colon for these PIA lesions and we can see and measure those. So we measure those in centimeters and we have a scale of zero being normal, one mild, two moderate and three severe. So we take the lesion length times the lesion score and add that together throughout the intestine to get a lesion severity index. Severity index the lesion scores were the lowest in the alicin treated group. It was statistically better than the controls. That severity index of the 25 was the mean score on those 60 pigs and it was 75 was the lesion severity score in the controls. And then lincomycin was intermediate at 33 and was not statistically better than the controls. And I should say ablacin wasn't statistically better than the lincomycin in these parameters either, just numerically better.
Speaker 2:So before we, you know, get into the treatment, we should probably talk about how ileitis is detected and, you know, at what threshold producers make the decision to treat their herd.
Speaker 3:Yeah, the key is to always be on the lookout.
Speaker 3:The key is to always be on the lookout. Be on the lookout visually for clinical ileitis Whenever you see abnormal diarrhea. Our first diarrhea score is a one and that's just a soft cow, pie-like diarrhea. It's not normal diarrhea. My producers will tell me that, doc, that's just normal diarrhea and no, there's no such thing as normal diarrhea. That's my favorite saying and you've probably heard me say that before, but so you walk by it.
Speaker 3:If you see clinical diarrhea in a pig that's in a grow finish pig, especially a pig that's in a grow finish pig, especially a pig that's over 100 pounds or the fecal color score is also a really good thing to look at visually. If you see blood in feces, we we score our fecal color score on a mild, moderate, severe score as as as well severe is a classic black, tarry, red, black or-black or black-red melana. Two-color scora is just some blood in it. It might be dark, brown or orange, but there aren't too many things that are going to cause bloody diarrhea. We don't bloody diarrhea is brachyspira, hyaluronic acid or hamsonia. We don't have that in very many of our farms, although it might be on the increase. But if you see blood, something's wrong and then get a diagnosis, don't walk by anything clinical without knowing what it is. Fecal PCRs are the gold standard anti-mortem test, whether they're taken with a direct fecal sample or you take fresh fecal samples and pool up to three to five at the most, or if you take oral fluid samples.
Speaker 3:Don't walk by clinical diarrhea without knowing what it is, because my rule of thumb, if it's clinical in a grow-finish pig, you've got the rest of the population. That's subclinical or clinical and they need to be treated with water medications. It's very, very cost-effective to treat with water medications, as I can talk about in a benefit-cost analysis that we did on this study. So that's number one. Look at it visually. Number two is monitor it. So that's number one. Look at it visually. Number two is monitor it. Use the fecal PCR with the oral fluids and take fecal samples and routinely monitor your finishing barns, at least once or twice a year, so you aren't walking by it.
Speaker 3:Iliitis only lasts in an individual pig. Iliitis will probably only last for 35 to 42 days. In some bad situations they might shed for out to 70 days and the population might only have ileitis in that grow-finish barn for six weeks or two months, months. So it's your job to find it and take action if you have a clinical diarrhea to water medicate. And then what we also learned from this trial is the correlation between fecal shedding and average daily gain. So there was a moderate correlation of 0.51 in this trial, showing that as fecal shedding decreased, that average daily gain dramatically decreased also, and it had a high P value. So my rule of thumb is whenever you have fecal PCRs or oral fluid samples approaching 30, a CT value of 30 at the University of Minnesota they're in the diagnostic lab you better take action because that means there's lots of fecal shedding. And we also showed that there's a moderate correlation between fecal shedding and lesion scores.
Speaker 3:So the more lesions you have, the more fecal shedding and lesion scores. So the more lesions you have, the more fecal shedding you have and the more average daily gain and feed conversion loss you have. So when your CT values get down around 30, take action and water medicate. Or if you see clinical diarrhea with blood or just diarrhea consistency scores, then treat with water medication because it's very, very cost effective.
Speaker 2:Time is definitely of the essence, and don't walk by those signs of clinical diarrhea. You talked about water-soluble treatment being an effective delivery method and looking at some costs too with this trial. Won't you dive into that more for us and explain why that is such an effective delivery method?
Speaker 3:Well, it's because of the long incubation period of Lawsonia that that, if you, by the time, you see, by the time we saw clinical ileitis here and we gave them uh, we gave them a uh. 10 to the 10th, that's uh, that's 10, 10 million bacteria per pig and it took 13 days before you saw clinical science. But by on day seven, none of those pigs were shedding. Um, by day 13, 100 of those pigs were shedding. By day 13, 100% of those pigs were shedding and the fecal PCRs were down in that 25 to 27 CT value at the University of Minnesota. I keep saying at the University of Minnesota, because the PCR CTs, pcrs aren't standardized across labs. So, for example, at Iowa State they only go through 35 cycles to identify their Lawsonia PCRs, where at the University of Minnesota they go through 40 cycles. So the numbers are going to be a little bit different. But at the University of Minnesota, for example, when you get down to around 30 that I just mentioned 30 is when you do a qPCR that's about five times 10 to the fourth. So that means there's 50,000 Lassonia bacteria per gram of feces and it only takes somewhere between a hundred and a thousand bacteria to infect a pig and start the whole disease process in that population. So you know you've got a lot of bacteria that the pig is spreading fecal to oral throughout that, throughout that population. So you know you've got a lot of bacteria that the pig is spreading fecal to oral throughout that population.
Speaker 3:Regarding the cost-benefit analysis that you asked about, I just used some basic assumptions from today's markets $67 per 100-weight live, $300 per ton of feed. The cost of ablison in our study was 63 cents per pig for that five-day period and the cost for lincomycin was 32 cents per pig over that five-day period. So ablison was a more expensive treatment. However, the benefits of Abelson outweighed those of lincomycin and both of them were much, much better than the controls. For example, the extra body weight on day 35. For Abelson the pigs averaged 11.4 more pounds heavier on day 35. The lincomycin pigs were seven pounds heavier. You put that $67 per 100-weight live and put a value on that, that's $7.50 for Abelson and $4.50 more value for the poundage on that pig. The feed savings and feed conversion rate for Abelson was $3.24. The feed savings for linchomycin, compared to the controls, was $1.25. So the total benefit just in performance.
Speaker 3:I didn't look at mortality here but there's benefit in mortality as well. The total benefit for Abelson was $10.73 just in this trial by treating with Abelson, and it was $5.83 for the lincomycin water medication. So the benefit-cost ratio. When you divide that by the cost of the antibiotics, the benefit-cost ratio turned out to be about the same. It was 17 to 1 for alicin and 18 to 1 for lincomycin. But the bottom line here is that you spend 31 more cents for antibiotic costs for alicin and it pays you back $4.90 in performance improvement with average daily gain and feed conversion rate. So under the constraints of this trial, alicin was the better antibiotic in this ileitis challenge.
Speaker 2:What other recommendations would you have for producers that think they're, you know, seeing an ileitis challenge?
Speaker 3:Well, water Medicaid, as you alluded to, is the best treatment because we're treating the population. We got to treat the subclinical. It looks like 80% of those pigs are just fine but they're shedding More than likely they're shedding. Some might be normal. It depends upon where in the course of the disease they are when you're taking these PCRs. But water medication is the best treatment for population. But still, if you have pigs that have bloody diarrhea or a PHE, you need to inject those pigs.
Speaker 3:The best thing for that individual pig is an injectable antibiotic. For Lawsonia, lincomycin and Tylen are common ones. Also, if there was enough disease in this trial, if this were a field outbreak, we would have followed up with feed medication. Also, because you medicate in the water for five days, you still have to follow up with feed medication for another couple weeks after that because the water medication doesn't completely stop all shedding. It reduces shedding. Actually the Avilacin reduced shedding 8.3 times more than the lincomycin on day 21 after the water medication was taken out. But still, if it was a field outbreak, you use all methods of delivery. Water medication is the best. If they're really sick pigs you want to inject them and you want to follow up in the population, depending upon how much clinical signs you see and if you have mortality or not with feed medication as well. So I guess hopefully that answered the question.
Speaker 2:Yeah, no, no, as we wrap up our discussion here, any other key takeaways you'd like to leave our audience?
Speaker 3:Well, I'd like to just encourage swine veterinarians to try to be more diligent in monitoring for Lawsonia. Like I said, I think we walk by it and leave money on the table regarding subclinical for sure, and maybe even clinical. If you think clinical diarrhea is normal diarrhea, you're walking by it and leaving money on the table, so monitor it, get in there and hang some. It's easy to hang oral fluids. Easy to hang oral fluids. It's easy to take some fecal samples from suspect feces and pool them for PCRs. Know where you are and catch it. Catch it early so you can treat it with water medication and save your producer a lot of money.
Speaker 2:Great pieces of advice, dr Nate Winkleman, with Swine Services Unlimited. Thank you so much for joining us today.
Speaker 3:I appreciate the opportunity. Thanks a lot.
Speaker 1:This episode has been brought to you by Farmgate Animal Health, a growing business that puts livestock first. Farmgate provides a proven portfolio of technically supported, high quality products that are the foundation of custom herd health protocols. By offering multiple options for active ingredients, concentrations and administration routes, farmgate provides you with choices to fit your needs and get you the results that you want. I'm Sarah Muirhead and you have been listening to Feedstuffs In Focus. If you would like to hear more conversations about some of the big issues affecting the livestock, poultry, grain and animal feed industries, subscribe to this podcast on your favorite podcast channel. Until next time, have a great day and thank you for listening.