how do you ferment sawdust for hog feed?

I've read that you can substitute 20 or 30% of feed with fermented sawdust, but I don't know if you are supposed to just put it in with the feed when that's fermenting or ferment separately.  On really cold days I want to give them dry feed anyway.  (I pasture the pigs but to maintain the balance of power I have to bribe them with a good deal of feed or they will decide that 6.7 joules is not enough reason to stay in their paddock and go create a new one).  I have a free source of (damp) course sawdust.  Thanks for any tips or links.

I know nothing about it but I kinda wonder if it's a "you can get away with adding this much filler" sort of thing.  Is it actual nourishment for them?

When I was in MN sawdust from “Popple” ( I suspect White Poplar” )was used by some to mix in feed. I never used it. It is a very sweet wood. So, my suspicions are that it is going to depend a great deal upon the source of that sawdust.  

I have never fed sawdust though I can see how it could be used as a feed.

If the fermented sawdust is wet I would not mix the fermented with feed due to the water content tainting the feed.

I found this article that might be of interest:

https://pubmed.ncbi.nlm.nih.gov/6280357/

Do hogs eat bark and twigs in their own?
I can imagine fermented sawdust giving them some feed benefit, if only from digesting the fermenting organisms themselves.
Hmm.

High carbon pig manure also seems like it could be useful.

It does not seem right. I never saw my pigs eating twigs, bark nor even dry grasses. It would rather belong to some big industry practices:
-take wood trash, mix with toxic glue and sell as building material
-take wood trash, ferment, feed to animals
Wood dust is excellent to use as barn bedding or compost dusting.

Thanks team.

I have seen them eating twigs off the apple tree, suckers, and they definitely eat some grass. It is hard to observe them since if they see me coming they come over to me to guilt-trip me into more feed more feed, but I will see if I can see that.

The sources I’ve seen for this are in Africa, small-scale farming, and some academic publications.  There are some that add weird chemicals to the sawdust for their formula, and I only want to use stuff I would more or less eat myself(kombucha vinegar, whey, apple cider vinegar).

I’ll try that link

William Bronson wrote:Do hogs eat bark and twigs in their own?
I can imagine fermented sawdust giving them some feed benefit, if only from digesting the fermenting organisms themselves.
Hmm.

High carbon pig manure also seems like it could be useful.

They’re famously enthusiastic about clearing briars and bittersweet, but I’m not sure if they actually eat that much.  

Anne Miller wrote:I have never fed sawdust though I can see how it could be used as a feed.

If the fermented sawdust is wet I would not mix the fermented with feed due to the water content tainting the feed.

I found this article that might be of interest:

https://pubmed.ncbi.nlm.nih.gov/6280357/

Thanks Anne, yes I’d read that and a farmer nearby has fed some sawdust to cows, but of course that’s a different story from pigs digestion.  I hope more folks will chime in.  Thanks!

I have to say at first thought I cannot believe anybody would think sawdust in any form would be a good idea!
BUT I have found a few topics on the matter.
From; sawdust and pigs
There are tales of farmers with stretched resources in times of recession padding out their animal feed with all sorts of spare materials from around the farm, including sawdust.
But in 2012 an Iowa, US-based cattle farmer Bob Batey claimed to have developed a method of turning sawdust from his lumper mill into feed for his cows.
More than just padding out the feed until prices drop, Batey purported that his sawdust recipe is very nutritious and that his cows eat it up happily.

Wood contains cellulose, an important component in animal feed, but it’s unfortunately covered in lignin, which gives the wood its strength and prevents its digestibility in animals.
But by breaking down the lignin barrier and freeing up the cellulose, you can create a hearty meal for ruminant farm animals.
This is exactly the process carried out on Batey’s farm, and the theory behind sawdust feed has been backed up by Iowa State University.

African-solution-turns-sawdust-into-pig-feed

A solution that recycles pigs’ faecal waste and turns sawdust into a rich source of carbohydrates for pigs to consume is assisting pig farmers in Uganda cut on feed cost by upto 30 percent coming at a time when the price of feeds has faced north in recent years.

The solution commonly known as IMO which is derived from its formulation indigenous micro-organisms has been in use for the last 2 years.
The magic solution is made from simple micro organisms which occur naturally in the environment made by culturing. “These can be viruses, bacteria, fungi or any other organisms.
It is a composition that can be made and cultured in the laboratory depending on the type.
The beneficial micro-organisms are then mixed with carbohydrates and rock salt,” explained Dr. Richard Kirigwanja a veterinary doctor in Uganda and one of the brains behind the innovation.
..........Unlike other solutions the best way of serving the solution to the pigs is through sprinkling over the animal fecal matter, feeds and saw dust.
Dr. Kirigwanja explained that the cost of feed to the pigs while using the solution is reduced by over 30 percent. “The saw dust is source of carbohydrates, locked in sawdust called cellulose and no enzyme in mono gastric animals can break it down.
The micro organisms in IMO break down the cellulose locked up in the sawdust and avail nutrients to the animals so the animal will feed on part of the saw dust.
Additionally, the fecal matter of the animals is a rich source of protein not digested by the animal.
So the micro organisms go ahead and break down the protein locked in the fecal matter and the animals goes back to feed on it and therefore, this cycled feeding caters for 30
percent leaving a farmer to only provide 70 percent of the feeds,” he explained.

I was mixing grass into their slop by just letting it soak long enough. Another year I was boiling kidney beans and adding it to their feed, wonder if boiling sawdust would help break it down to make it more digestible.

Kenneth, that is what I read about feeding sawdust.

The sawdust is boiled for maybe 10 minutes.  Maybe it is boiled and then fermented, I can't remember.

Here is an updated link on the subject:

https://www.monitor.co.ug/uganda/magazines/farming/imo-an-innovative-way-to-practise-piggery-1644206

See also:
and


I am certainly going to try this!

And another update
Clean pig pens

S Philomena wrote:I am certainly going to try this!

Amazing!  Thanks so much for the video links.  I'm definitely going to be doing some more digging into this and it's (I'm sure) huge and varied uses.  Gads do I love biology!!!  LOL  I'm totally nerding out.

You can ferment it by soaking the damp sawdust in water and adding a probiotic or fermented feed starter. Let it sit for a few days to ferment before adding it to their regular feed.