Emerging health challenges for laying hens and pullets

Learn about emerging diseases facing the egg and layer industries.

(Photo by Terrence O'Keefe)
(Photo by Terrence O'Keefe)

Eric Gingerich, DVM, technical services specialist, Diamond V, presented emerging disease issues in the layer industry at the U.S. Poultry & Egg Association's (USPOULTRY) Live Production, Welfare, and Biosecurity Seminar in Nashville, Tennessee, on September 18, 2018.

Gingerich discussed emerging or re-emerging layer diseases including roundworms, Salmonella, Gallibacterium anatis septicemia, variant strain infectious bronchitis virus (IBV), ulcerative dermatitis of brown cage-free layers and spotty liver disease.

Roundworms

Roundworms are not as much an economic or mortality issue but more a concern from the potential for them to be in an egg, Gengerich explained. This is not good for publicity or how the egg market is perceived. "There are operations that have had several cases; one operation has had 10 complaints in a year," Gingerich said.

Roundworm In Egg

From a marketing standpoint, finding a roundworm in an egg could be devastating to the egg industry. | Eric Gingerich

Salmonella

Group C Salmonella was not on Gingerich’s survey list last year; however, he did spend ample time discussing it. Rose Acre Farms was recently impacted, and also an operation in Missouri in 2015 and 2016 as well.

“We are thinking there are a lot of cross-contamination issues with these products,” Gingerich said.

In the Missouri instance, the operation was selling to over 100 restaurants with complaints from only five. That operation was forced to close. The Rose Acre Farms' instance resulted in a recall, depopulation of the site and repercussions from the government that are still in process.

These outbreaks have led to many questions from industry leaders, especially since they were contaminated on the surface shell, not inside the egg itself. “Why are these Group C Salmonella outbreaks causing disease in humans? Are they more pathogenic than other Salmonella strains? Why are these not being eliminated during our cleaning and disinfection process? Is contamination happening after we wash them,” Gingerich asked.  

Gingerich explained that the Salmonella issue is scary because there was a field test done in Iowa suggesting that there is Salmonella on many farms at high levels. To prevent the issue, Gingerich suggested that producers increase egg wash water pH to 11, using alkaline detergent, and utilize a chlorine rinse step in lieu of UV light sanitation.

“The UV lights are a controversial issue; it was a USDA-approved method, but the FDA apparently doesn’t like it,” Gingerich said.

Producers should also minimize water/condensation in the house, utilize feed and water additives known to reduce Salmonella levels in feces, use an autogenous bacteria containing Group C Salmonella, blow dust off eggs before they enter the processing area, not place floor eggs in the farm pack of eggs sent to processing and restrict movement of pallets, flats and boxes, he added.

Gallibacterium anatis septicemia

"Gallibacterium anatis septicemia seems to be increasing in prevalence, especially in the Southeast, although we have seen it in the Midwest as well; it affects layers of all ages” Gingerich said.

This is a typical septicemic disease that brings on acute death, Petechial hemorrhages and is often confused with E. coli infection. “Mortality can be over 1 percent, per week,” he said. It may also lead to shell abnormalities.

This disease must be cultured to be diagnosed as the lesions associated with it look similar to those associated with other diseases.

Variant strain IBV

Variant strain IBV has been seen in Northeast, Midwest and Southwest parts of the U.S. and Ontario, Canada. “There are two syndromes that we are seeing with this,” Gingerich said. There is early exposure (first two weeks), which was originally called ovulating non-laying syndrome, and is now called false layer syndrome. This is when the oviduct is nonfunctional, but the ovary is.

“Early exposure to this variant strain IBV is damaging the oviduct tissue, not allowing it to develop normally, so the oviduct is non-functional,” Gingerich said.

The other syndrome occurs while the flock is in lay, which results in a drop in egg production and poor egg shells. “Infected birds waddle like a penguin,” Gingerich said.

There is no treatment. Producers are having trouble identifying non-layers in order to remove them as they continue to show normal comb development and pelvic spread, Gingerich explained. Certain vaccinations may help prevent the issue.

Ulcerative dermatitis of brown cage-free layers

Ulcerative dermatitis of brown cage-free layers is a problem that has been present in Western Ohio since 2014. It has impacted various companies, but only brown layers.

There was only one current flock affected at the time of the presentation.

It results in high mortality. “The birds get an ulcer right in the middle of their back, and we’re not sure how it starts,” Gingerich said. “We will lose as much as 50 percent of the birds in the cycle.” It starts out small and gets bigger, like a flesh-eating bacterium. Professionals have had no success isolating it.

Rodents, insects, chemical irritants and wounding have all been ruled out as the cause. Antibiotics and disinfectant powders were not successful in helping with the issue.

Ulcerative Dermatitis of Brown Cage-free Layers

Ulcerative dermatitis has been a problem in Western Ohio since 2014. | Eric Gingerich

Spotty liver disease

Spotty liver disease is a serious problem in Australia. It was also seen in several pastured flocks in the Midwest. “We saw 12 cases in outdoor access facilities this summer,” Gingerich said.

Its prevalence is believed to be associated with wet weather. Spotty liver disease can result in mortality rates of 1 to 2 percent per week and a loss of egg production of 5 to 10 percent.

The cause has been determined to be Campylobacter hepaticus, and it can be treated with antibiotics.

spotty liver disease

Spotty liver disease is becoming more common in the U.S. | Eric Gingerich

Final thoughts on emerging layer diseases

“Layer health is very good overall,” Gingerich explained. Emerging diseases are present but not significant currently.

The biggest concern is multiple Group C Salmonella outbreaks. Avian Influenza is still a concern to producers and will continue to drive biosecurity standards, Gingerich concluded.

Read more: Designing an effective egg farm biosecurity program: www.WATTAgNet.com/articles/34784

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