Reusing chicken litter shows benefits

Date:
June 10, 2020
Source:
American Society of Agronomy
Summary:
Beneficial bacteria in reused poultry litter can reduce Salmonella
levels.



FULL STORY ========================================================================== Chicken is the most consumed protein in the United States. According to
the National Chicken Council, the U.S. produced more than 9.2 billion
broiler chickens in 2019. US consumers spent more than 95 billion dollars
on chicken products.


==========================================================================
All these broilers -- chickens raised for meat -- need millions of
tons of litter, or bedding material. Reusing chicken litter can save
costs. There exists some health and safety concerns though.

A new study shows that the environment in reused poultry litter can
deter growth of pathogens like Salmonella.

"When you read or hear that broiler litter is reused to raise multiple
flocks of chickens, the typical reaction is that it must be bad for food safety," says Adelumola Oladeinde, a co-author of the recent study. "Our
study demonstrates the exact opposite." Oladeinde is a researcher
at the USDA's National Poultry Research Center in Athens. He and his
colleagues found that 'good' bacteria in used poultry litter can hinder Salmonella growth.

"It may be worthwhile to invest time and resources to characterize
the bacteria in reused litter," says Oladeinde. "We can develop the
promising ones into beneficial microbes for better chicken gut health."
The study also explored litter characteristics, such as moisture and
ammonia levels. These characteristics can dramatically affect the litter microbiome - - the mix of bacteria, fungi, and viruses in litter.



==========================================================================
"Our findings provide new information on the relationship between
the physical environment of broiler litter and its microbiome," says
Oladeinde. "Management techniques that account for both factors may
help reduce Salmonella in chickens." Chicken litter plays a big role
in determining broiler health. After a broiler chick gets to a farm,
it usually spends the next several weeks pecking and living on litter.

In fact, chicks begin to eat litter even before eating from feeding
troughs or drinking. The microbiome present in the litter likely become
the 'first settlers' in the guts of the chicks.

"These first microbes play a key role in determining gut health," says Oladeinde. "Therefore, it is critical to determine what a beneficial
litter microbiome looks like." The team collected samples of reused
poultry litter from the University of Georgia Poultry Research Center. The litter was used to raise three flocks of broiler chickens under conditions
like those used in broiler farms. "Each sample represents a unique
broiler litter environment," says Oladeinde.



==========================================================================
In the lab, researchers measured characteristics of the litter
samples. Then they added Salmonella to each sample. After that, the
samples were tested for levels of Salmonella, other bacteria, and
physical characteristics.

Within two weeks of adding Salmonella, most samples developed predictable microbiomes. Certain microbes, such as Nocardiopsis bacteria, seemed to
reduce growth of Salmonella.

That makes sense, according to Oladeinde. Some species of Nocardiopsis
bacteria are known to produce antibiotics and toxins. These compounds
could be keeping Salmonella levels low in the litter samples.

A key aspect of reusing broiler litter is how long to wait before
reuse. This waiting period is called litter downtime.

"For farmers, a shorter downtime will result in growing more birds
through the year," says Oladeinde. However, we know little about how
downtime affects litter microbiome.

Results from the study show that surveying levels of specific bacteria
could help determine if litters have had enough downtime. That could be
of big help to farmers.

"Poultry litter is a complex environment to study," says Oladeinde. "We
showed that the reused litter after two weeks of downtime had a microbiome
that was unfavorable to Salmonella." Oladeinde aims to repeat these experiments with litter from various sources. He also wants to test
for multiple Salmonella strains. "These studies will tell us about the underlying mechanisms behind reusing litter and reducing Salmonella,"
he says.

This work was funded by the United States Department of Agriculture, Agricultural Research Service.


========================================================================== Story Source: Materials provided by American_Society_of_Agronomy. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Maite Ghazaleh Bucher, Benjamin Zwirzitz, Adelumola Oladeinde,
Kimberly
Cook, Caroline Plymel, Gregory Zock, Steven Lakin,
Samuel. E. Aggrey, Casey Ritz, Torey Looft, Erin Lipp,
Getahun E. Agga, Zaid Abdo, Karamat R. Sistani. Reused poultry
litter microbiome with competitive exclusion potential against
Salmonella Heidelberg. Journal of Environmental Quality, 2020;
DOI: 10.1002/jeq2.20081 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/06/200610094051.htm

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