Fermented feed for chickens

That’s a great point — and you’re absolutely right, the caeca are busy little fermentation hubs.

I didn’t focus on them earlier because, in terms of fermented feed, most of what people are trying to influence happens upstream. By the time feed reaches the caeca, the bird has already absorbed the bulk of the “good stuff.” The caeca step in to ferment what’s left — mostly fiber and leftovers — producing short-chain fatty acids that support gut health and provide a bit of extra energy.

A couple key points:
  • The crop and caeca are not the same game — crop = early, simple fermentation (Lactobacillus), caeca = deeper, anaerobic cleanup crew.
  • Most critical nutrients are absorbed before the caeca, so they’re not the main driver of nutrition.
  • The microbiome is already well-adapted — adding fermented feed doesn’t “upgrade” it, it just changes the inputs, sometimes in messy ways.
And yes — some research used caecectomized birds, but even in intact birds, the consensus holds: properly formulated feed is designed to be digested before the caeca even get involved.

Chickens are not hindgut/butt gut fermenters in the way sheep or even rabbits are. They’re still primarily designed to extract nutrition upstream:
  • Proteins → digested and absorbed in the small intestine
  • Fats → absorbed early via bile-mediated pathways
  • Most vitamins and minerals → absorbed before the caeca
By the time feed reaches the caeca, what’s left is essentially the “leftovers bin” — useful, but not the main meal.

So when people say “the caeca are the most critical,” they’re usually talking about fiber fermentation specifically, not overall nutrition. That distinction gets lost.

So yes, the caeca mater — a lot. But they don’t need our help fermenting things ahead of time. Chickens already have a full, layered system dialed in. Sometimes we step in thinking we’re helping… and just end up complicating something that was working perfectly fine on its own, and apologies- Im just really geeky over avian nutrition. lol.

It’s not to say you can’t ferment feed — if your chickens enjoy it, eat well, stay hydrated, and you don’t mind the extra step, then it can absolutely be part of your routine. The issue, in my opinion, is the growing idea that it’s somehow required, which isn’t supported by poultry nutrition science.

I’ll also admit I have some questions about how quickly chicken feed “ferments” in home settings. In my own experience, feed can turn into a bubbly, active mix within 24–48 hours, while other true fermentation processes take much longer to stabilize. My theory commercial feeds already carry naturally occurring microbes, and once you add water and warmth, you’re essentially accelerating microbial growth — not necessarily creating a controlled or consistent fermentation. Research shows rapid microbial proliferation under warm, moist conditions, but that doesn’t always mean it’s stable or beneficial. And yes, I have made my own yogurt, kefir, kimchi, alcohol 🫢

So yes — ferment if it works for you. I just don’t view it as necessary, and in some cases it becomes more of an uncontrolled microbial experiment than a consistent nutritional strategy. Okay… I was bored and just wrote a novel. Sorry.
Characteristically informative, and ends with wit to boot. Thanks again.

Can you point me towards some refs where I can read about the current consensus further, because it is not entirely consistent with the most useful paper I've found on the caeca, which dates to 2013. Some pertinent excerpts from that are:

"Despite its conspicuous presence in the lower digestive tract of most domesticated poultry species, the nutritional significance of the caeca remains unclear... Of note was the finding that the microbial composition of individual birds varies vastly. Apajalahti et al. (2012) reported a highly significant correlation between the caecal microbial composition and the energy harvesting efficiency of individual birds, suggesting the possible role of the caecal microflora on production performance... The interaction between microflora composition, diet composition and performance is a very complex matter, and despite excellent recent reviews on some aspects (e.g. on the effect of enzymes by Bedford and Cowieson, 2012), a thorough review would require a separate, extensive discussion and therefore it is not in the scope of this review...

Karasawa and Maeda (1994; 1995) showed that protein utilisation was higher for intact than for colostomised cockerels when the birds were given protein-deficient diets supplemented with urea, thus indicating a beneficial effect of caecal fermentation. However, caecectomy was not shown to decrease nitrogen retention in a later experiment, even in birds given low-protein diets (Son and Karasawa, 2000)... [Ravindran et al. (1999)] indicates that for poorly digestible protein sources, the caeca and the colon may play a significant role."

https://www.researchgate.net/public...nutritional_roles_of_the_avian_caeca_A_review (open access).
 
I doubt in the wild seeds would be available year-round.
if you put a fish in a jar, and make the jar air tight, the fish will suffocate and die from lack of oxygen. So in this specific case, the water is anaerobic.
This is why you can get botulism from eating canned stuff that has not been preserved in the correct way (enough acid/salt/sugar).

If the jar is open the fish won't die. So the water in an open jar is aerobic.
My buckets of FF are open, or having a cloth over the top to keep bugs out in Summer.
 
This is very interesting; thank you.

I miss any mention of the caeca. Is that because scientific studies of chicken digestion have typically worked with caecetomized birds?

My understanding is that quite a lot more microbial activity goes on in the caeca, and that the chickens are then able to absorb more nutrients as bacterial/viral/fungal metabolites. I believe that fermentation of grains etc. feeds various microbes in the gut beyond the crop; it is not just about the lactobacilli.
This is true, yes the caeca acts the same as our appendix, it is the place where the various cultures are kept to alive to then be spread through the system. It also where the hardest to digest things get stuck then gradually broken down. Interestingly enough it looks about the same and is in roughly the same place also!
Fermented feed probably does feed the other microbes, since many of them work in sequence with the leftovers from one being digested by another, same with us. There will also be other strains in the ferments that will help resupply the gut (and caeca), however the predominant bacteria will likely be lactobacilli and yeast, simply because those are the ones most present in the environment and able to survive the submersion. Many of the needed strains cant really survive outside of a digestive system for long, and are rare to just be found on the food. Mammals get these strains from the birthing cannal and their mothers milk, chicks from whatever managed to enter the shell and when the broody directs them to eat her poop. Chicks with no adults around have to slowly build their supply up and often have a harder time building their digestive system. The same with formula fead babies.
 
That’s a great point — and you’re absolutely right, the caeca are busy little fermentation hubs.

I didn’t focus on them earlier because, in terms of fermented feed, most of what people are trying to influence happens upstream. By the time feed reaches the caeca, the bird has already absorbed the bulk of the “good stuff.” The caeca step in to ferment what’s left — mostly fiber and leftovers — producing short-chain fatty acids that support gut health and provide a bit of extra energy.

A couple key points:
  • The crop and caeca are not the same game — crop = early, simple fermentation (Lactobacillus), caeca = deeper, anaerobic cleanup crew.
  • Most critical nutrients are absorbed before the caeca, so they’re not the main driver of nutrition.
  • The microbiome is already well-adapted — adding fermented feed doesn’t “upgrade” it, it just changes the inputs, sometimes in messy ways.
And yes — some research used caecectomized birds, but even in intact birds, the consensus holds: properly formulated feed is designed to be digested before the caeca even get involved.

Chickens are not hindgut/butt gut fermenters in the way sheep or even rabbits are. They’re still primarily designed to extract nutrition upstream:
  • Proteins → digested and absorbed in the small intestine
  • Fats → absorbed early via bile-mediated pathways
  • Most vitamins and minerals → absorbed before the caeca
By the time feed reaches the caeca, what’s left is essentially the “leftovers bin” — useful, but not the main meal.

So when people say “the caeca are the most critical,” they’re usually talking about fiber fermentation specifically, not overall nutrition. That distinction gets lost.

So yes, the caeca mater — a lot. But they don’t need our help fermenting things ahead of time. Chickens already have a full, layered system dialed in. Sometimes we step in thinking we’re helping… and just end up complicating something that was working perfectly fine on its own, and apologies- Im just really geeky over avian nutrition. lol.

It’s not to say you can’t ferment feed — if your chickens enjoy it, eat well, stay hydrated, and you don’t mind the extra step, then it can absolutely be part of your routine. The issue, in my opinion, is the growing idea that it’s somehow required, which isn’t supported by poultry nutrition science.

I’ll also admit I have some questions about how quickly chicken feed “ferments” in home settings. In my own experience, feed can turn into a bubbly, active mix within 24–48 hours, while other true fermentation processes take much longer to stabilize. My theory commercial feeds already carry naturally occurring microbes, and once you add water and warmth, you’re essentially accelerating microbial growth — not necessarily creating a controlled or consistent fermentation. Research shows rapid microbial proliferation under warm, moist conditions, but that doesn’t always mean it’s stable or beneficial. And yes, I have made my own yogurt, kefir, kimchi, alcohol 🫢

So yes — ferment if it works for you. I just don’t view it as necessary, and in some cases it becomes more of an uncontrolled microbial experiment than a consistent nutritional strategy. Okay… I was bored and just wrote a novel. Sorry.
Very nice! Since yeast in nature lives especially on grains and legumes and lactobacilli are basically everywhere im sure the commercial feeds to have some. Lactobacilli and yeast open to the air are very quick growers. Yogurt only takes 24 hours to culture, at max, keifir often as low as 8. Kombucha ect take longer its really more about how much of the original nutrients you want transformed by the cultures present. Alcohol takes so long not because it takes so long for the strains to grow, but because it takes that long for them to consume the sugars and turn them into alcohol. It is also limited by the lack of o2, if you left your alcohol ferment open to the air with some particle block the other strains would take over and turn all the alcohol into vinegar very quickly.

The caeca doesnt digest the bulk of the nutrients yes. It is still incredibly helpfull though, and many of the fats they do produce their are incredibly necessary.

I dont think we HAVE to ferment their feed, I only do it roughly once a week. I do think that if you dont give fermented scraps, or let them free range, then their digestive systems will suffer if you don't ferment their feed at least sometimes. The strains they would be eating in nature are way more abundant and varied then you find in the feeds. Not only that but many if the added vitamins are in forms not easily digested (the same for our vitamins, you should see what DL-Alpha Tocopherols and Titanium Dioxide do to us! 😱) and shift to something better when pre-fermented.
 
Characteristically informative, and ends with wit to boot. Thanks again.

Can you point me towards some refs where I can read about the current consensus further, because it is not entirely consistent
These mostly support what the poster was saying. They do indicate the caeca seems to digest more than just fiber, such as the second one that specifically mentions protiens. The fist though, since most of the fiber is converted to fats the higher energy chickens would be getting a more sustain blood sugar level by the available fats.
 
These mostly support what the poster was saying
And you know this how?

I do not take things on trust.

What exactly have you consulted to form your opinion of the consensus among veterinary surgeons? Or anything else for that matter. Assertion is not a substitute for research, argument, and references to reliable published sources.
 
Characteristically informative, and ends with wit to boot. Thanks again.

Can you point me towards some refs where I can read about the current consensus
Yes- give me a second to go back over notes from previous years- we have house guests, and running around like a chicken with my head cut off and I type slowly- especially when children are here trying 'feed and pet' the chickens... haha.
 
And you know this how?

I do not take things on trust.

What exactly have you consulted to form your opinion of the consensus among veterinary surgeons? Or anything else for that matter. Assertion is not a substitute for research, argument, and references to reliable published sources.
1. It was right there in the linked articles if you know how to speak "science"

2. Years and years of nutrition and biology study

3. A bachelor's of science with a focus on nutrition and animal biology (from a nursing college if that helps you)

3. Years of working at a vet clinic and speaking with nutritionists

4. Personal observation

Look you don't have to believe me if you don't want to, but either go do your own research and bring the "opposing" sides or stop attacking my credibility. Its kind of ridiculous.
 
1. It was right there in the linked articles if you know how to speak "science"

2. Years and years of nutrition and biology study

3. A bachelor's of science with a focus on nutrition and animal biology (from a nursing college if that helps you)

3. Years of working at a vet clinic and speaking with nutritionists

4. Personal observation

Look you don't have to believe me if you don't want to, but either go do your own research and bring the "opposing" sides or stop attacking my credibility. Its kind of ridiculous.
that's just a lot more assertion. I won't bother you anymore.
 

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