"Giving probiotics to baby chicks reduces the risk of
Salmonella in eggs and other diseases later in life." - Statement
found on a popular chicken related blog on March 22, 2016.
Not all of what is suggested in this statement is entirely
wrong. The blog page where this
statement was pulled from does a good job of referring the reader to sound
research on feeding probiotics to chickens.
However, where the blogger falls down is that they refer the reader to
research on broiler chickens and not laying hens. The statement above was specifically targeted
to laying hens because it mentions eggs.
Yes, giving broiler chicks probiotics does help them, but a laying hen
is a completely different management system and therefore their level of
exposure, over a much longer lifetime, creates a completely different situation. You cannot compare apples to oranges and
needless to say, by throwing in backyard management systems you have tossed in
a pineapple for comparison.
I will agree that giving chicks probiotics does help them to some
degree in their gut microbiome. You may
also see improvements in their feed conversion and growth rates. However, broiler chickens are raised to about
6-8 weeks whereas a laying hen may stay on this earth for years. During that time, any protection that could
be imparted by giving that laying hen chick probiotics is gone before it even
reaches the age of laying its first egg.
The only other thought process here is that you may wish to
repeatedly dose the chicken with probiotics.
The beneficial effect of repeated exposure of probiotics for the
long-term has yet to be proven. Laying
hens, with their longer lifespan, can be repeatedly exposed to Salmonella
(there are several hundred strains to choose from) and each time they will need
to eliminate it from their bodies.
Keeping your chickens as a backyard flock exposes them to stressors that
are not the same as commercial birds. Therefore,
the performance of any probiotic used in commercial conditions will not apply
to backyard birds unless specific research is done with the said probiotic on
multiple backyard flocks to determine an average response. So that should explain why I mention
comparing apples to oranges, and even pineapples, above.
It takes a large dose of Salmonella to infect an adult bird. And most often if a chick is infected, the
likelihood that the chick is going to clear its system of Salmonella in a
matter of a few weeks is far greater. This
means that, although it can happen, it is less likely that a chicken is going
to shed Salmonella for many, many weeks or even a few months. So by giving the chick probiotics, you are
likely imparting protection for only a few weeks, at a time when the gut
microbiome is just developing. Yes, at
that time, when their immune system is not as strong as an adult bird, you want
to impart as much protection as possible and probiotics are a good idea. But to claim that by giving a chick
probiotics you are going to impart protection for the lifetime of the hen is
wrong. Since a healthy bird with a good
functioning immune system can potentially remove Salmonella by itself then
probiotics may not be needed. If you are
dosing a bird with probiotics as it is trying to eliminate any Salmonella from
its body using its normal immune functions, then the real question becomes the
following: Are the probiotics doing the
heavy lifting or is it the immune system doing its job?
Probiotics are likely displacing organisms within the gut that are
moderately affecting things like feed conversion or nutrient availability. It is the hope of probiotics to displace
pathogens, which can, like other bacteria or microbiota, access the gut of the
bird through different pathways. Your
goal as a chicken owner is to reduce the exposure of your birds to these
different pathways. Knowing that as your
bird ages, they are being repeatedly exposed to different organisms, means that
you will need to use good biosecurity and stay on top of your good management
practices. Probiotics are nice to have
on hand, but are by no means a requirement to successful chicken keeping.
Unfortunately, the quote above also states that the risk of
salmonella in eggs will be reduced. No
reputable research to that effect (within the egg) has been shown. Sometimes research finds slight reductions in
bacteria levels by feeding probiotics, and they may be statistically
significant, however, the actual numbers are only slight and not at all
meaningful for you, the backyard chicken owner.
Significance and meaningful can be two very different things. You may see a reduction, but if the levels are
not enough to have any real, true meaning in real-world circumstances, then one
must understand that probiotics are not a replacement for using sound
management practices within your flock. I
emphasize that bacteria on the inside of the egg in the discussion can be
detrimental especially in sauces or dishes that are not cooked. You can reduce bacterial levels on the
outside of the shell which is good, but washing eggs before eating them can
also do good in reducing bacterial levels.
Lastly, the quote also states that by giving probiotics, a reduced
risk will be imparted against “…and other diseases later in life.” This statement is too broad. There is no indication of what diseases are
being referred to and so that makes this part of the statement a red herring. The
real topic being discussed is the Salmonella level in eggs being affected by
probiotics given to the birds in the chick life stage. As was stated previously, when birds are
exposed to the right dose, or other stressors, probiotics given as a chick will
not impart protection at later life stages.
Beware of broad claims when you are shopping the internet for
information. Most times, if it sounds
too good to be true, then it often is.
Thankfully, in this case, we have teased apart the truth from the myth
in the aforementioned statement so that you can better approach this topic with
science in mind.
Response provided by Dr. Brigid McCrea, Ph.D.
Associate Professor and Extension Poultry Specialist
Delaware State University
* This is another fine example of how bad information can quickly spread across social media. Example: How many people read this blog? How many times are readers now going to post on other chicken related blogs and forums, "Giving probiotics to baby chicks reduces the risks of Salmonella in eggs," spreading the bad information even further? Reading a study is one thing, having the knowledge to understand what the study means is another. ~ Andy Schneider (The Chicken Whisperer)
