Poultry Health Today

Limiting stress in broiler flocks is key to preventing birds from succumbing to an infectious respiratory disease which is showing a resurgence in some areas of the US, according to a poultry expert.

The feed additive sodium bisulfate administered to broilers during a coccidial challenge appeared to benefit gut integrity.

Investing in vaccination programs to develop cross-protection against some of the most common strains of Salmonella could help limit the number of foodborne outbreaks of the pathogen, according to a poultry expert.Charles Hofacre, DVM, PhD, president, Southern Poultry Research Group Inc., said increases in drug-resistant foodborne outbreaks of Salmonella highlighted the need for everyone in the broiler sector to work on reducing incidences of the pathogen.And he said that vaccinating broilers and breeders could help limit multiple types of Salmonella seen in processing plants, which could in turn reduce food-safety issues.

A few essential adjustments in the way infectious bronchitis vaccines are handled and administered at the hatchery can improve vaccine efficacy, Brian Jordan, PhD, assistant professor, University of Georgia, told Poultry Health Today.“Frozen vaccines that come out of liquid nitrogen have to have a little bit more care,” Jordan cautioned.

Mountaire Farms is the first animal protein company to carry the One Health Certified label, demonstrating its commitment to animal production standards established by the program.Don Ritter, DVM, director of technical marketing for Mountaire Farms, said that to carry the One Health Certified label, his company had to be audited by USDA to verify its compliance with the program, which was officially launched in January 2020.There are five pillars to the One Health Certified program: disease prevention, veterinary care, antibiotic use, animal welfare and environmental impact.

Greater flexibility is needed in official Salmonella and Campylobacter testing regimes in order to support poultry producers and processors who are trialing new interventions to tackle both pathogens.Dr. Ashley Peterson, PhD, senior vice president of scientific and regulatory affairs, National Chicken Council, said the US poultry industry has made great progress in reducing Salmonella levels to well below the standards set by the USDA’s Food Safety and Inspection Service (FSIS).However, because methods for controlling Salmonella might not have similar success with Campylobacter, processors and producers need freedom to trial different interventions without facing punishment if those techniques are not as successful as they hoped.

Surveillance aimed at pinpointing the type of infectious bronchitis virus (IBV) that’s circulating in poultry flocks is essential to control of the disease, Mark Jackwood, PhD, University of Georgia, told Poultry Health Today.There are a lot of different IBV types circulating in the poultry industry. “So if we don’t know what’s out there, we don’t know which vaccines to pull off the shelf to use...,” he said.

Newcastle disease (ND) throughout most of the US remains stable, but the industry needs to be on guard for changes in the virus that may require adaption of ND vaccines, Guillermo Zavala, DVM, PhD, president, Avian Health International, cautioned in an interview with Poultry Health Today.The ND strains circulating in most of the poultry-dense regions of the US are still the milder, lentogenic type that cause some respiratory and uniformity problems. They are nothing like the virulent form of ND that started in California backyard flocks, ultimately making its way to a few commercial flocks where it caused substantial losses.

Preventing birds from getting sick is perhaps the biggest challenge encountered when transitioning from conventional to “no antibiotics ever” (NAE) production, Tony Newsome, division manager, Fieldale Farms, told Poultry Health Today.Fieldale Farms was one of the first poultry companies to transition to NAE production. It’s been a long process, Newsome said, but the company has figured out how to raise healthy NAE flocks.“We basically started from the ground up,” first with pullets and breeders, he said.

Acceptance of a petition designating avian leukosis lesions on poultry carcasses as a trimmable condition is expected to reduce waste and improve efficiency at processing plants while allowing meat inspectors to focus more on food safety, said Ashley Peterson, senior vice president, scientific and regulatory affairs for the National Chicken Council (NCC).USDA Food Safety and Inspection Service (FSIS) recently granted the petition by NCC, which requested the agency amend its regulations.“The existing regulations require that any lesion in a leukosis check results in the whole carcass  ⸺ that’s the carcass and the viscera ⸺ being disposed of and not going into the food supply,” Peterson told Poultry Health Today.

Producers making the switch to cage-free egg production need to ensure they and their staff are properly prepared for managing potential increases in Salmonella and other health challenges associated with those systems.John Brown, DVM, Zoetis senior technical services veterinarian, said cage-free operations typically experience higher levels of Salmonella, coccidiosis and necrotic enteritis, as well as more “old” diseases such as fowl cholera.And unless staff have the right skills to transition from conventional systems and respond to increased disease challenges, cage-free enterprises run the risk of not being as productive as they could be.

Vaccinations and other preventative health measures are more critical than ever as the US egg industry shifts toward cage-free and no-antibiotics-ever production, according to an industry expert.Ian Rubinoff, DVM, director of global technical services at Hy-Line International, said the decision by major retailers to switch to cage-free production systems by 2025 has increased health and management challenges for producers.Coupled with growing pressure to use fewer antibiotics — and in some cases none at all — means producers need to be more proactive than ever in handling bird health and welfare, he said.

Focusing on chick quality from the moment eggs enter the incubator is critical to ensuring birds have the best chance of being healthy and productive in no-antibiotics-ever (NAE) systems.Donna Hill, PhD, of Donna Hill Consulting, said rearing strong chicks is critical to the success of NAE systems, as weak birds are more likely to succumb to bacterial challenges and other issues in the field.And without the support of antibiotics to back them up, birds in these systems risk sacrificing growth for survival, resulting in less-developed chicks which expend more energy on hatching, and higher mortality rates.“Incubation is a growth equation,” she told Poultry Health Today. “The better job you do with incubation, the better developed the embryo is at harvest.”

Training chicks and pullets so they are prepared for life in cage-free egg systems is critical to ensuring they meet their full productive potential, according to a leading veterinarian.Isa Ehr, DVM, a technical services veterinarian with Hendrix Genetics, said birds reared in conventional pullet houses could find moving to cage-free barns difficult, leading to feeding and laying issues.But, he said, by raising pullets in systems which closely resemble or match the lay houses they will be transferred to, egg production is less likely to be affected.

The poultry industry’s gradual switch to cage-free egg production has underscored the need to rethink disease-control programs and address health and welfare challenges unique to layers in these production systems, according to Jean Sander, DVM.With more than 200 US retailers pledging to sell only eggs produced in cage-free systems by 2025, producers are eager to make the switch to fill this growing demand.  However, the cage-free production gives rise to health problems not commonly seen in conventionally raised layers, she told Poultry Health Today.And while many producers have learned about them through trial and error, it’s best to be proactive to ensure the health, welfare and performance of the birds.

Blending two commonly used antibacterial treatments could help processing facilities take better control of Campylobacter and reduce the risk of food-borne illnesses, according to scientists.Researchers at Colorado State University found that using a combination of peroxyacetic acid (PAA) and low-pH buffered sulfuric acid is significantly more effective at tackling Campylobacter than using either treatment alone.And they said timing the treatment so it is used after birds are cut up means that reductions in bacterial load could last even longer than when compounds are used individually.Speaking to Poultry Health Today, Keith Belk, PhD, head of the animal science department, said with no vaccines available to control Campylobacter on the farm, the current focus for tackling the pathogen has to be in processing. 

How do you look for new serotypes of a virus that might be circulating in an area? Sentinel birds are a good place to start, according to Abigail Reith, DVM, a technical services veterinarian for Zoetis.In a recent study in Arkansas, she used infectious bronchitis (IB) spires designed to look for serotypes of infectious bronchitis virus (IBV), a coronavirus that is a highly infectious respiratory disease in chickens.“We knew that, potentially, we had a new serotype floating around, so we wanted to use the single birds to see if we could isolate [the virus] and identify it in the broiler breeder houses,” she told Poultry Health Today.

The bacterium Escherichia coli (E. coli), has re-emerged in broiler operations, said Nicolle Lima Barbieri, researcher at the University of Georgia. The bacterial pathogen’s appearance in broilers seems to coincide with poultry companies’ switch to ‘no antibiotics ever’ (NAE) programs. Avian pathogenic E. coli (APEC) is not well understood, she told Poultry Health Today.“Avian pathogenic E. coli gained some genes that we call virulence factors, which make the bacteria able to cause disease,” Barbieri said. “These bacteria in the field can change and virulent genes can transfer from one bacteria to the other.”This is the same E. coli that can cause illness in humans, she added. “Some studies correlate APEC to the same E. coli that causes neonatal meningitis in babies, or urinary tract infections in humans,” she said.

Feeding higher levels of copper and zinc in the diet, managing litter moisture and controlling coccidiosis are keys to stopping necrotic enteritis (NE) in poultry raised without antibiotics (RWA), Dan Moore, PhD, president, Colorado Quality Research, told Poultry Health Today.“We're seeing a very consistent result with copper,” Moore said. Instead of the typical 8 to 10 parts per million inclusion level in the diet, they have used 250 to 275 parts per million in some studies.The combination of copper and zinc in the feed, long used in the swine industry, has also yielded encouraging results in poultry for reducing the incidence of NE, he reported.

Resistance is unlikely to be a problem in coccidiosis bioshuttle programs, Greg Mathis, PhD, Southern Poultry Research, told Poultry Health Today.Bioshuttle programs start with hatchery vaccination against coccidiosis followed by use of an in-feed anticoccidial. Alternative products are also often used, Mathis said.The key to success with bioshuttle programs in no-antibiotics-ever (NAE) production, he said, is allowing immunity to develop after vaccination. Toward that end, Mathis recommended one and a half or two coccidia cycles after vaccination — the coccidial lifecycle being 7 days — before using an in-feed anticoccidial.

Taking a closer look at why incidence of Salmonella and Campylobacter varied widely on farms in the same production system helped to demonstrate the importance of management and communication with growers, Bruce Stewart-Brown, DVM, senior vice president, food safety, quality and live production, Perdue Farms, told Poultry Health Today.In a study of 150 farms over the course of 2 years, Perdue found that for Salmonella, some farms rarely had any, some had a lot and others were in the middle with inconsistent patterns. The company noted similar trends with Campylobacter.

An unusual presentation of bacterial septicemia in broilers underscores the importance of obtaining a good history and obtaining input from bird caretakers, David French, DVM, a staff veterinarian with Sanderson Farms, told Poultry Health Today.Broilers in two of the company’s divisions started getting sick at 35 to 40 days of age. There were respiratory signs as well as severe fibrin production in the abdominal cavity, particularly around the heart. “They had a pericarditis, a perihepatitis and a polyserositis that was so dramatic that visiting veterinarians were grabbing their cameras to get pictures of it,” French said.

Food safety challenges linked to Salmonella could be tackled more effectively by better understanding the sex life of bacteria, according to a leading US government veterinarian.Researchers have known for some time that Salmonella and other bacteria have a sexual form of reproduction called homologous recombination.However it seems the process, which sees bacteria swap sections of their chromosome with each other and ultimately create hybrid strains, could be much more common than initially believed.

A new label under development for meat and poultry products will represent production that seeks a balanced approach to poultry production and marketing.

Excellent systems of communication between farm staff and veterinarians are critical when it comes to managing disease outbreaks and reducing their potential spread.Eric Heskett, DVM, PhD, at Case Farms in North Carolina, told Poultry Health Today that communication is critical to being able to act as fast as possible to contain outbreaks, identify disease and protect bird health.Using an example of a broiler breeder manager in Ohio who saw a sudden, 14-fold increase in mortality in a matter of a day (24 hours), Heskett explained how a text message alerted him to a potentially catastrophic disease outbreak and gave him the chance to work immediately to contain any disease risk.

Poor uniformity, lameness and reduced water consumption are tip-offs that broilers may be infected with variant reovirus, Erin Riley, DVM, staff veterinarian at Sanderson Farms, told Poultry Health Today.The epidemiology for variant reovirus isn’t clear, Riley said, but it spread across the southern US very rapidly through transport of live poultry and hatching eggs.When the latest epidemic first emerged in 2012, it was a sizeable problem because hen flocks were naïve. Once vaccination with a killed autogenous product was initiated in pullets, variant reovirus became less of a problem, but it still occurs, he said.

Understanding the impact specific on-farm interventions can have on Salmonella is critical to helping the US poultry industry meet government standards around the disease, according to a leading veterinarian.

Tackling endemic poultry diseases as a community rather than as individual producers can play an important role in controlling and limiting their spread.

Necrotic enteritis (NE) is not only a big problem in flocks raised without antibiotics, there’s a wide variation in how it presents itself, Steve Davis, DVM, president of Colorado Quality Research, told Poultry Health Today.