Health & DiseaseLivestockSoil Rehabilitation

Can a Cow Produce 100 Pounds of Pig Feed a Day? (Poland)

This entry is about cows and pigs. But before we get down and dirty let’s start with some basic facts about humans’ and pigs’ nutrition to make sure we’re on the same page.

What does it take to fatten pigs efficiency?

It is said that all animals need proteins to be fattened efficient. Is it really true? Not entirely — in fact all we really need is a substance which proteins are made of: amino acids. Some of which the body can ‘produce’ on its own. These ‘self-made’ substances are called non-essential amino acids and they are synthesized mainly from carbohydrates and other amino acids.

And those amino acids that humans and pigs cannot produce themselves are called essential amino acids.

Essential amino acids:

  • phenylalanine
  • valine
  • threonine
  • tryptophan
  • isoleucine
  • methionine
  • leucine
  • lysine

We shouldn’t forget that children also need two additional amino acids:

  • histidine
  • arginine

Here’s where it gets interesting — if we don’t provide our bodies with sufficient amounts of essential amino acids, over time this will lead to amino acid deficiency and that can result in:

  • Heart diseases (our heart simply will not have enough amino acids to regenerate)
  • Depression
  • Kwashiorkor
  • Loss of hair
  • And many, many more

But in rich countries you should not be afraid of an amino acid deficiency — unless you’re on a very strict diet where either quality or quantity of essential amino acids doesn’t meet one’s daily requirements or if a particular person has some digestive or health related problems.

The same rules apply both to humans and pigs, with which we have a lot in common, especially when it comes to digestion. But it may be a little bit more difficult to notice this since the life span of a pig is much shorter than ours (domesticated pigs can live up to 15-20 years, and wild pigs 4-8 years), so the deficiency and its consequences are not so easily recognizable. For example: What if the speed of fattening or speed of growth shows that a pig has nutritional deficiencies? At the end of the day feed conversion ratio (a simple measure of an animal’s efficiency in converting feed mass into increased body mass) is just an indicator of how much food it takes for the pig to grow, not necessarily for them to be healthy. The animal industry has a long track record of using substances that enhance an animal’s growth, but are not particular healthy for the animals or the people who may ultimately eat them. Think of subtherapeutic use of antibiotics….

Studies show that a shortage of even just one essential amino acid in pigs’ feed will cause them to convert it into lard (pork fat) instead of producing structural protein (meat). Of course there’s nothing wrong with that as long we are raising pigs just for our own needs — pork lard from pasture-, orchard- or forest-raised pigs was traditionally used by our ancestors here in Poland for centuries. But if you have a business to run, then fat pigs is not what you’re looking for….

Here’s some simple math:

First of all the meatiness ratio (how much meat a pig embodies) is dropping, and most consumers prefer lean pork. E.g. example 1 pound of lard cost about 0, 5 – 1, 5 PLN and 1 pound of meat cost around 5-7PLN in Poland. So that means pork-breeders get paid less for fat pigs.

Secondly, protein is the most expensive ingredient in pigs’ feeding formula (assuming you have to buy it from an outside source).

And last but not least — it takes more calories of pig feed for the pig to create fat than to create protein (9 kcal for 1g of fat and just 4 kcal to create 1g of protein)!

So pig breeders will lose x3 if they sell fat pigs.

All the amino acids are needed at the same time — if even one is missing; the proteins from food will not be used efficiently. Old textbooks on biology, nutrition and animal husbandry differentiate complete protein (animal) and not complete (plant). The amino acids, just like a wooden barrel holding water, can have 99% efficiency, but even if one tight plank is missing, then the barrel fails. And back to barrels…. Water can be stored only to the level of the lowest hole in that barrel. It does not matter that the barrel has a capacity of 500 l (providing large amounts of protein pig feed) but what counts is how high the lowest hole in that barrel is (the essential amino acid lacking in pig’s diet).

If we want to raise pigs on pasture, usually we should watch for those amino acids that are the limiting factor for pigs’ growth (because of their lack of pasture sward). These are: lysine, methionine, threonine and tryptophan. Theoretically one could supplement pigs’ feed with rapeseed meal or soybeans, but considering that most of those plants are genetically modified, and they are usually cultivated in a really unsustainable way, it’s better to find other source of essential amino acids.

The cow — a valuable potential source of feed for pigs

What do all these arguments about essential amino and pigs have to do with a simple cow?

Cows are excellent for supplying very large quantities of missing essential (and not so essential) amino acids for pigs, as well as a little easily digestible calories.

Pigs for cured parma ham are raised on pasture; they also get whey — a byproduct from producing cheese — and sweet chestnuts. Such a ‘feed formula’ provides pigs with all the essential amino acids they need and also makes pork taste sweet. Is the permaculture principle “produce no waste” met here? I’m sure it is!

Perhaps readers can begin to see the picture, for how to sustainably raise cows and pigs together: The cow gives milk, from which the milker makes butter and cheese. Remnants of the production (buttermilk and whey) can be given to pigs to eat. This is a wholesome feed — and as you can see, there’s no longer the need for the soybeans (GMO or otherwise).

One cow can deliver more than 100 pounds of pig feed!

Despite appearances, milk, buttermilk and whey are not the only food for pigs which cattle can provide. Another potential source of food for the omnivore swine is… cow manure.

What happens to plants that a cow swallows?

Interesting things happen with plants digested by cows. First of all you need to know that, for a cow, plants are not the direct source of food — to increase the nutritional value of their feed cows are using a middle man: bacteria. Cows are chewing the plant to increase the surface area of the plant on which bacteria can act (aren’t cows "increasing the edge?"). These bacteria digest plant food and then they multiply. After they multiply, the pre-digested plant food with all bacteria moves to the next stomach (they have four!). A cow (or rather a farmer who feeds it), in contrast to the pig, does not need to worry about the quality or quantity of essential amino acids they receive. It’s enough that the cow will get an appropriate amount of protein, fiber and carbohydrates. Even better, the cow does not even have to consume large amounts of proteins because the bacteria in their stomachs are able to convert urea into proteins (nitrogen source for bacteria to produce a protein). There are known cases in which a large part of the cows’ diet was sawdust, urea (nitrogen source for the synthesis of proteins by bacteria), and cow-lick made of molasses and micronutrients.

Why can a cow eat food which doesn’t contain all the essential amino acids?

A cow, whose feed may not contain a full set of amino acids, produces in its stomach the right conditions for the growth of bacteria. These bacteria are, however, able to produce all the essential amino acids from non essential amino acids. When the bacteria multiply on a digested plant then the cow moves it to the next stomach.

Cow’s manure is potentially valuable but
cheap pig feed. One can see small dots — it’s
where maggots have turned into flies.

Why cow manure may be feed for pigs

Pigs are omnivores. Nature has given them the task of “environmental cleaners”. Apart from the fact that they eat plants and animals, they also eat droppings of other animals, with great pleasure. Cow manure is composed in a large part from the undigested parts of plants, and bacteria. And, as mentioned earlier, manure contains all the essential amino acids. They may therefore be a valuable "concentrate feed" for pigs. In addition, if cows are fed grains, part of the grain passes through cows not fully digested. Under normal conditions, this type of product would be wasted.

The benefits of cow manure in pig nutrition

The first and fairly obvious benefit is the use of cow dung as an energy source for pigs. The second is the previously mentioned protein and essential amino acids. The third benefit of feeding pigs with cow manure is providing them with micronutrients and vitamins, especially from the vitamin B group (including B12).

What percentage of a cow’s manure could a pig’s diet comprise?

The FAO (UN agency dealing with food and agriculture) has published data on the experiment conducted in Mauritius in 1976 in which pigs were fed 40% cow feces , 40% molasses and 20% commercial compound feed. Pigs on this regime did grow more slowly than in the control group, but the breeders achieved good economic results due to the low prices of such mixtures.

Depending on several factors, one cow can provide food in the form of manure for 3, and up to 17 pigs.

It’s determined by:

  • cow’s age and diet
  • what part of pig’s diet is to be manure
  • age of pigs

How to integrate the possibility that pigs can be fed cow manure into Permaculture design?

If we want to raise pigs and cows the permaculture way you could follow these suggestions.

On the first day the pasture is grazed by cows. On the second day they move to a new pasture cell, and pigs move into where the cows were yesterday. They will eat cows’ manure, roots and part of the pasture sward. The third day the pigs are moved to where the cows were at day two and chickens are moved to where yesterday’s pigs were — they will eat a large part of the parasites found in pig feces. In addition, they will scratch the manure, spreading it and accelerating its incorporation into the soil, along with all its nutrients.

This way the pasture is used in a “Holistic Management” way, so the land will not be overgrazed and the amount of weeds will be lessened. Same pasture can be actually a silvopasture-based system in which walnuts, chestnuts, fruit and other fodder trees are also being grown. This agroforestry system should be protected from winds by windbreaks.

Can pigs be fattened in this way without purchasing commercial feed?

At the moment it is difficult for me to say whether the above-mentioned pasture, cow manure and whey are able to provide full nutrition for pigs. I am inclined to believe that adding walnuts and chestnuts to their diet, pigs will grow well and we will enjoy knowing for a fact what our animals eat.

Can pigs be fed with the feces of other herbivores?

Yes, pigs can be fed feces of other herbivore animals such as horses, goats, rabbits…. A very good source of food for pigs is horse manure — because horses digest less efficiently than cows, so "horse apples" contain more seeds, etc., that means they contain more calories.

I would like to know your experience with feeding pigs with manure.


Wojciech Majda is founder of Polski Instytut Permakultury (Polish Permaculture Institute).


  1. We have done this for years, but using rabbit, chicken, and goat wastes. I have also collected manures from horses and cattle nearby for the pigs. They love it!

    I pretty much make big pigs of the manure, and let the pigs spread it out, and eat what they want when they want.

    If you have small livestock, don’t ignore the slaughter waste. Cook or ferment the slaughter waste and then feed to pigs. It is loaded with essential vitamins and amino acids, and can function as a primary protein source, if you have enough. It’s especially good for sows right before they go in with the boar. This gives them a boost and you will get bigger litters. Our largest litter was 19 piglets, 16 survived with a pastured sow that got a lot of slaughter waste regularly.

  2. The traditional saying was that you can raise a pig on two cows. What was meant was that for every two cows you have a pig will grow eating their manure because the cows pass through so much good nutrition out in their manure. Farmers used to keep pigs down under the dairy barn so that the manure could simply be shoveled down the hole to the pigs along with waste hay, waste straw, wasted feed, etc. Apparently this worked for centuries. The cycling of nutrients like this in nature is normal. I do not know if an ill flavors came through in the meat because remember the rule: feed for flavor. You are not likely to win over customers explaining this to them.

    We raise pigs on pasture and whey which makes up over 90% of their diet – it varies seasonally and in the winter we replace fresh pasture with baled hay. We have about 400 pigs out on pasture and have been doing this for over a decade delivering weekly to local stores, restaurants and individuals so we know it works. Pigs can be raised on pastures and feeding them some additional protein such as whey does boost growth. However there tends to be too much focus on speed of growth by all too many people. Speed and efficiency are not as important out on pasture as they are in a confinement operation. It doesn’t matter if it takes the pig all day to gather its nutritional requirements on pasture vs thirty bites from the trough on commercial feed. Either way the pig is growing. The pastured pig works harder, yes, but it still grows well and avoids the cost of grain. Grain isn’t evil, it’s just expensive.

    You sentence above “We shouldn’t forget that children have also two additional amino acids” perhaps needs ‘have also’ changed to ‘also need’ since the way it is written seems like you’re advocating eating children. Or perhaps you are…

    -Walter Jeffries
    Sugar Mountain Farm
    in Vermont
    where the pigs are eating pasture, not cow manure or commercial feed…

    1. Thanks for the amusing comment Walter. Yes, we don’t advocate eating children (anyway, they get stuck in the teeth – very annoying). The wording is my fault in proofing (the author is Polish) – fixed now.

    2. Hi Walter,
      thanks for noticing the mistake. I’ll check amino acids profile of children and get back with you soon ;-) BTW I know a guy who sell a protein powder with amino acid profile of human muscles…

      I don’t think it will make the taste of meat worse – boars eat a lot of deer manure and they taste good. I also think that manure from pasture fed cows is better than from cows fed commercial feed.

      You raised very good point with marketing. It’s something that might be difficult to explain to customers, so it would be better to just run pigs on pasture after cows. It’s sort of the same thing as marketing that “our chickens are fed 100% vegetarian diet”. Some people might prefer that, but is it natural?


  3. I like the idea of chickens following pigs following cattle.
    pigs will eat most faeces including human. When I was in Thailand 25 years ago you could barely pull your pants up after squatting in the bush after a “dump” before the pigs snuck up behind you and gobbled it up- this was alittle disconcerting in the dark- especially being male with my “sausage” dangling!
    Asia has a long history of feeding pigs human excrement.

  4. It may also be important to point out that in Australia it is illegal to feed pigs on the waste (manure – not whey) of any other mamal. I understand the rules may be different in the US Walter? I suppose you need to way up the ethical issue of whats more important profit or population health, would seem if you’re following permaculture and abiding by the ethics Care of People should come before profit – but in these days seems not to be the case. Reference attached –

  5. Yep, knew it would come – illegal in Australia. No surprise. I wonder if they have actually tested feeding mammal faeces to pigs and have a scientifically proven result that it will transfer ANY disease? Any scientists out there that think there are good chances of transference of a disease in this way?

    1. Actually Dylan, there are numerous diseases where humans are infected from animal sources. They are known as “zoonotic diseases” and include serious diseases such as tuberculosis, brucellosis, leptospirosis and Q fever. I haven’t included the really obvious worm infections such as Tapeworm and roundworms which are readily transmitted between several species such as cows, pigs and humans.

  6. @Martyn and Dylan
    I come from a country where parliament in the last 25 years introduced approximately 300-140 acts of law a year. So to some extend you would not be able to do anything because there is a law that prohibits you from doing that (and another that says that you have to do it). Because of that it’s not important what law say, it’s important what laws are enforced…

    It’s true, that feeding pigs with manure is illegal in Australia (if the document that Martyn link is true, and I have no reasons to believe it’s not), but:
    -Is it illegal to run pigs after cows on pasture?
    -Is it illegal to fertilized your pasture/fields with stable manure if some animals are that pasture
    -Is it illegal to create small piles of cow/horse manure on pastures where pigs are?

    I guess until you put manure in the feeder how someone can know are you actually feeding your pigs..? Just make sure to have a feeder with some sort of “legal” pig feed in it. I guess it’s another benefit of raising your pigs on pasture.

    1. Right now it’s illegal for pigs to access any mammals manure or protein produces. In Australia we are currently trying to control infection from a virus called Hendra. This virus is passed to humans via flying fox droppings, it has a better kill rate on humans then Ebola. So the question is what else is out there the same or worse? Are you going to take respond ability for being the first person to kill somebody with pork or risk catching a similar disease from a pig? Up to you, but I’m not.

      1. Hi,
        I was not aware you have this sort of problem in Australia. Does that mean pasture or raising pigs outside will be banned, as pigs can get feces of wild living mammals if they are on range?

        In Europe or USA this problem does not exist, so this practice can be utilized there safely (as it was used for hundreds of years).

  7. Nice article excellant example of free press; Permaculture Etc
    I hope it isnt illegal to follow cows in a rotation!

    I think Australia is a net importer of pork nowadays!!!

  8. Great great article, i wonder about the fat on a small scale tho. Lard is a great energy source, you can make soap, lubricant, lighting from it. So maybe on a small homestead it makes more sense to have a bit more fat on the pig?
    Does this apply to chickens too? As in, protein not being as important as people think?
    Also have any of you producers heard of using hotuyinnia – a semi invasive plant as a natural growth promoter? There is a study about it being used on chickens. We use its good for the immune system and the chickens love to eat it.

    1. It’s about customers preferences. Nowadays people don’t want to eat animal fats, though it’s changing slowly. On farm animals that you will be eating, yeah it’s useful to have a bit more fat on them.

      Proteins are not that important, amino acids are. It apply to pigs, chickens, humans, horses…

      I have not heard abut hotuyinna. I guess it’s something I need to learn more. It sound promising!

    1. Joel Salatin suggests a four-day wait to give the larva a chance to start growing but not enough time to mature and fly away and become pests that do more harm than good elsewhere. Seems to me that would be a good compromise.

  9. Thank you for all the science. Have to admit I skimmed over it, but I’ll be going back. I raise pigs in and around cows, chickens and turkeys, in small paddocks at the homestead and then out in the woods with a couple cows. Have to tell you – the pigs will NOT follow a bucket of grain when snarfing up turkey or chicken manure. I think they like it dried best – not sure – kinda hard to see exactly what getting gobbled up ;) Very much like Walter described the old cow/pig barns, I envision putting a turkey roost directly over the pigs bedding!! Still, I’ve wondered about the “you are what you eat issue” with turkey [email protected]#!

    I’ve come to the conclusion that pigs are GREAT at making Pork! And that’s almost we need to know. It’s more about them being pork making machines than our skill at deciding what they eat, as long we’re not keeping them in confinement. If we can give them “natural” choices, then I think it’s Natural Pork.

    Can you see pigs lounging under chestnut trees that the turkeys also happy to roost in? Or finding the cow pie or the nest of eggs? Sounds natural to me ;)

  10. I have a big plantation of sugarcane and consumption rate is low, since am not near a sugar manufacturing factory. Few kilometers away, I have a cattle farm in hundreds. After reading your articles am convinced I can used mixed cow dug manure and crashed sugarcane as pig feeds. Please advise me if this is a good thinking before I start on this project.

  11. How many chemicals do you put on your sugarcane and administer to your cows?? These chemicals will accumulate over time in the pigs. If you are chemical free it could be really good…

    1. The cows feed on natural grass on the farm except for the spray of chemicals for killing ticks. Likewise the sugarcane are not sprayed but grows naturally on the plantation.

  12. Thanks for that interesting article. It’s got me dreaming about a 5 acres with a few cows, few pigs, and a whole passel of cooks.

  13. My big concern would be build up of any parasites in your system. Several diseases and parasites can pass from cows to pigs. And any time a disease gets into the pigs, it is much more virulent to humans.

  14. It seems to me that if we are all trying to mimic nature so that we can undo the damage done from abuses of the past, IMPORTING manure from other properties, and forcing our pigs to eat a diet that has a percentage of manure in it that is not found anywhere on earth in nature is actually diametrically opposite of our stated objectives. And I dare say that such an effort will become the abuse that will be the cause of health and ecological problems of tomorrow that future generations will have to deal with while cursing us for the absurdity of our unnatural decisions.

    1. You obviously did not read the article or you would not have made such a pointless statement. There is not a single mention of importing manure from anywhere or forcing pigs to eat anything. Pay attention.

  15. Love this. Thanks so much for all the thought, research and inspiration in this article. Sharing this on my YouTube Channel NOW.

  16. Have a question. I have 4 pigs am raising and feeding is a challenge, my neighbour has 4 cows
    Can I be using his cow dung I add in small grain and give to my pigs daily??
    I will grateful

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