POULTRY HIGHLIGHTS OF A ROUNDTABLE DISCUSSION HEALTH T O D A Y ® INFECTIOUS BRONCHITIS: EVOLVING STRATEGIES VIRUS FOR AN EVOLVING AUGUST 2019 • WASHINGTON, DC INFECTIOUS BRONCHITIS: EVOLVING STRATEGIES FOR AN EVOLVING VIRUS WELCOME T he evolution of infectious bronchitis virus (IBV) is a continuing challenge for poultry producers and veterinarians. In broilers, this highly infectious coronavirus can present in its traditional form as respiratory disease, predisposing birds to secondary bacterial infections. Relatively newer on the scene are potentially deadly nephropathogenic IBV strains. In any form, IBV impairs animal welfare and is an important source of economic loss for poultry producers. Vaccination is key to IBV control. Although homologous vaccines are considered to be the JON SCHAEFFER, DVM, PHD most effective, development of a new vaccine for every new IBV strain that emerges is difficult Director, Poultry Technical Services, Zoetis to impossible. Finding an effective existing vaccine or combination of vaccines that will [email protected] zoetisus.com/foodsafety cross-protect is a worthwhile venture, but there’s no guarantee of success. Zoetis recently hosted a roundtable featuring renowned IBV experts as well as practitioners who shared their knowledge about IBV. These proceedings are highlights from the conversation and are provided with the hope they will help the industry achieve better control of IBV, improve animal welfare and minimize IBV’s financial burden. Sponsored by POULTRY HIGHLIGHTS OF A ROUNDTABLE DISCUSSION HEALTH T O D A Y ® TABLE OF CONTENTS 1 IBV TRENDS...................................................................... 4 2 IBV DETECTION................................................................ 5 3 IBV IN BROILER BREEDERS.............................................. 6 4 IBV AND IMMUNITY.......................................................... 6 5 IMPACT OF NO ANTIBIOTICS EVER.................................. 7 6 IBV EVOLUTION AND SPREAD.......................................... 8 7 ROLE OF IBV VACCINATION.............................................. 9 8 VACCINATION STRATEGIES.............................................. 11 9 IBV CROSSPROTECTION.................................................. 12 10 VACCINATION OF BROILER BREEDERS............................. 14 11 IBV AND NEWCASTLE DISEASE PROTECTION.................. 16 12 HOW MANY IBV VACCINE SEROTYPES?............................ 18 13 VACCINE APPLICATION PITFALLS.................................... 19 14 MINIMIZING VACCINE REACTIONS.................................. 22 15 IBV ARKANSAS CONUNDRUM.......................................... 24 16 REFLECTIONS.................................................................... 25 IBV KEY: In conversation, poultry health specialists often use abbreviated terms when describing long, numeric names of IBV serotypes. Here’s a key to the ones used in this discussion: DMV/1639 = IBV Delmarva 1639 • GA08 = IBV Georgia 08 • GA13 = IBV Georgia 13 • GA98 = IBV Georgia 98 • PA/1220 = IBV Pennsylvania 1220 INFECTIOUS BRONCHITIS: EVOLVING STRATEGIES FOR AN EVOLVING VIRUS PANELISTS MARK JACKWOOD, P h D UNIVERSITY OF GEORGIA MARK BURLESON, DVM WAYNE FARMS KALEN COOKSON, DVM ZOETIS DAVID FRENCH, DVM SANDERSON FARMS MEAGAN SLATER, DVM MOUNTAIRE FARMS POULTRY HIGHLIGHTS OF A ROUNDTABLE DISCUSSION HEALTH T O D A Y ® SARAH TILLEY, DVM FIELDALE FARMS MODERATOR: JEAN SANDER, DVM ZOETIS BRIAN LADMAN, P h D UNIVERSITY OF DELAWARE GUILLERMO ZAVALA, DVM, Ph D AVIAN HEALTH INTERNATIONAL INFECTIOUS BRONCHITIS: EVOLVING STRATEGIES FOR AN EVOLVING VIRUS 1 IBV TRENDS ...if significant respiratory diseases pop up, it’s typically due to a new variant IBV. “ MARK BURLESON, DVM ” ? SANDER ? SANDER ? SANDER Would practitioners on the panel What geographic regions do your What I’m hearing is that the IBV briefly give us an idea about the operations cover, and do the IBV serotypes seen vary regionally. impact of infectious bronchitis in serotypes you see differ from one But given that, are you seeing an their respective operations? region to another? overall increase in problems with bronchitis, or is it really more of BURLESON FRENCH a shifting landscape? I’d say it’s our biggest respiratory issue. At Sanderson Farms, we see regional Bronchitis seems to be a year-long challenges that are a little different from TILLEY struggle — tracking variants as they arise one area to the next. We cover the We routinely take serum from processed and staying ahead of them. Southeast from Texas all the way over to flocks. In summertime, IBV calms down a North Carolina. I would say in Texas, our bit, whereas in winter titers will increase. FRENCH biggest challenge has been Newcastle But generally, I’d say our titers stay IBV Arkansas tends to be a nagging disease (ND). For IBV, our biggest relatively stable. problem for us. This year, we thought we challenge was with DMV/1639, which was had everything under control, particularly primarily in south Georgia, although we FRENCH with our vaccination program, but then found a little of it in Mississippi as well. In I’d say it’s a shifting landscape. A lot of we had our first experience with the Mississippi, we mostly find GA08. So, our problems with bronchitis before this IBV variant DMV/1639. It caught me there’s a bit of a different challenge in past year were self-induced with vaccine completely by surprise. We didn’t even different regions. application. This past year, it’s been a little know we had a respiratory disease. bit of a different scenario with DMV/1639 We were trying to explain some lost BURLESON and IBV evolving and then spreading. It’s feed conversion and stumbled upon We cover a lot of the Southeast from been a greater concern for us this year. DMV/1639. So, we have it in our operation, Arkansas to North Carolina and all the Maybe a little bit more of a bronchitis and it’s been a new challenge to figure out states in between. It’s very geographical challenge. I expect to see a new IBV how to keep it under control. That’s been — there are different IBV serotypes in variant emerge about every 5 years. our biggest issue. different places. For instance, we’ve isolated DMV/1639 isolates only in south BURLESON SLATER Alabama and in Arkansas. I agree. There is a seasonal aspect to Poultry flocks on the Delmarva shore have bronchitis. Generally based on my experienced quite a bit of bronchitis and SLATER experience, summer is always better, and continue to struggle with control of Mountaire has isolated GA13 in North winter and spring tend to be the worst. DMV/1639 — probably for the last 3, if not Carolina flocks. We’re going to try to do However, if significant respiratory diseases more, years. Prior to my position with more surveillance and see what’s going on pop up, it’s typically due to a new Mountaire Farms, I worked as a consulting in that area. On the Delmarva shore, variant IBV. veterinarian in Pennsylvania where I got there’s been quite a bit of DMV/1639 as quite a bit of experience with DMV/1639 well as some GA08. It was the same in Problems can also arise if someone in broilers. We saw the impact on feed Pennsylvania when I was there. misapplies vaccine, or maybe you decide conversion and a little bit of airsacculitis. to go to a different vaccine manufacturer The challenge was finding a vaccination and the new vaccine just doesn’t play well program that didn’t cause more with your current program. But I’d say airsacculitis than DMV/1639. primarily the ebb and flow of variant bronchitis viruses is what we struggle with from year to year. 4 POULTRY HIGHLIGHTS OF A ROUNDTABLE DISCUSSION HEALTH T O D A Y ® 2 IBV DETECTION With GA13, we didn’t have a huge increase in mortality, but the processing plant complained about airsacculitis. “ SARAH TILLEY, DVM ” ? SANDER have other confounding factors. I think ? SANDER Are problems due to IBV usually it’s more of an issue at the plant than What about secondary infections? detected during live production or in the field. Someone in our organization at processing? once called it a silent airsacculitis where BURLESON you really don’t know you have any issues Those are primarily issues with FRENCH until the plant calls you and says, “Hey, Escherichia coli. When we found DMV/1639 in Georgia, it we’re basically shut down or our line was an interesting experience. We were speeds are down...with airsacculitis.” FRENCH off about 3 to 6 points in feed conversion It was mentioned earlier that there’s a and were trying to figure out why. We put TILLEY seasonality to it, and I think that has to do together a posting session. We looked at I agree that most of the impact is in the with the extra stress factors on the birds in 10 flocks of various ages. Those flocks plant. With GA13, we didn’t have a huge wintertime. In general, if you’ve got a appeared to be normal, healthy birds. increase in mortality, but the processing problem in the summertime and going There had been no mortality on the farm plant complained about airsacculitis. into fall, you can expect to have a and no flushing, but almost every bird we miserable winter. There are definitely opened up had a 3+ airsacculitis score. some outside circumstances that affect ? SANDER respiratory challenge. And I do think At first, I didn’t believe what I was seeing Dr. Burleson, what are the E. coli’s probably the biggest secondary and questioned whether the birds at “confounding factors” you bacterial infection. It can be either a posting were, in fact, normal, healthy referred to earlier? secondary problem or a primary birds. So, I went to the farm and picked pathogen, depending upon the type of out birds myself, only to find that it was BURLESON E. coli creating the difficulty. real. At first, I thought it couldn’t be I was thinking about the use or mis- DMV/1639 since there was no flushing, application of aggressive respiratory but the virus had changed to more of a vaccines, like IBV Arkansas or the respiratory challenge. I think we just Newcastle B1 strain.