How Much Land per Pig?

Pigs Coming Hither in the South Field at Sugar Mtn Farm

If you are a person with too sharp a pencil please put it down. You can not take numbers from one situation and misapply them to other situations willy-nilly. Each pasture is different. Pig sizes and ability to digest forages varies. Pastures vary with the season. Things change over the years. Management techniques are adjusted. How I do things in 2001 is not going to be the same as I do in 2011. How many acres we have open for pasture does not stay linearly smooth with how many pigs we have – e.g., in 2009 we cleared a large new section of fields but we didn’t all of a sudden quadruple the number of pigs we had. There are too many variables to apply numbers as absolutes and expect graphs to all look smooth. Instead, use the article below as a guide to give you a feel for one situation. Now relax and enjoy…

On the post “Keeping a Pig for Meat” Bill asked:

Some questions: I understand you have plenty of land for pasturing, so smell in minimized and the rooting and damage is not spread beyond the land’s capacity to continuously rejuvenate. How much would you think is the minimum to pasture a single pig?

The pigs don’t smell bad out on pasture. The association with stink probably comes from pigs that are confined. The same happens when you confine cows, sheep, chickens, people, etc. Additionally, pigs on pasture eat a great deal of fiber which is high in carbon and I suspect that the carbon in the grasses binds the nitrogen and other chemicals that cause the smell associated with manure. This is important to conserving the valuable fertilizer. If you can smell it you’re losing nitrogen and other useful elements to the air – fertilizer that farms pay big money for.

On the rooting and sustainability the key is rotation – Moving the animals to new spaces frequently. Managed Intensive Rotational Grazing are some of the key words to google and see this article.

Rooting is not very deep, typically only a few inches, and is actually good for the soil. If you’re looking to have a fancy suburban lawn then pigs are not ideal. But they will to a wonderful job of renovating old pastures like we have, gradually improving them without ever bringing in a bulldozer or bush-hog. Combine them with sheep and chickens and you have a great grounds crew.

As to how much land for a pig, we currently have about 200 pigs of varying ages on about 10 acres divided into paddocks. The pigs, divided into two herds, typically get access to one paddock at a time. That is right up at the current limit for our fields and we’re about to create more fields so we’ll have a lower stocking density which makes management easier. Our pigs range in size from little piglets of three pounds or so to big sows and boars of about 600 to 800 pounds. I would guess the total herd weight at about 40,000 lbs right now. It could be significantly more although it is biased toward the younger ages at this time. That is about 4,000 lbs per acre or about 20 finisher pig (200 lb) equivalents per acre. Remember they’re moving, not sitting.

Note that in addition to the pasture our pigs also get whey from cheese and butter making at the rate of about 2.5 gallons per hundred weight per day, some cheese trim, excess milk, cottage cheese, the occasional bread, occasional spent barley and excess from our gardens. Thus they are not getting 100% of their food from the 10 acres of pasture. If I only had the pasture I would probably only have about 25% to 50% as many pigs on it, so about 10 pigs per acre.

Another important consideration is the quality of the pasture. Forage varies greatly from scrub to lush legume pastures that are high in protein and that will make a big difference in the carrying capacity. Our pasture is about half brush and regen (young sapling poplar trees) with grasses beneath and over seeded with clovers. This is savannah style pasture rather than lawn like pasture many people picture. In time I expect to gradually further improve the pasture which will increase its capacity. The animals improve the pasture through their grazing, rooting and fertilizing. Liming also helps to raise the pH of our acidic soil to something more hospitable to grasses and high protein legumes.

Some interesting math:
1 acre is about 200 feet x 200 feet
10 acres is about 400,000 sq-ft
200 pigs on 10 acres is about 2,000 sq-ft per pig
or about 10 sq-ft per pound of 200 finisher pig equivelant
or about 20 finisher pigs per acre on average.

Again, remember this is a moving herd, not sitting in one spot. For figuring stocking densities I tend to use the number of ten pigs per acre. Note that gives our average pig size at about 100 lbs which is probably about right with a distribution of some in the large sizes (sows & boars) and many in the small sizes (piglets & growers). Currently our herd is a bit skewed in sizes as can be seen in the recent photo above. That changes over time, of course.

The (il)logical extrapolation of all that is 10 square-feet per pound of pig if you are giving supplemental feed – Thus for a single finisher pig it would be 2,000 sq-ft per pig or about 20′ x 100′. That is about 1/20th of an acre. I suspect you’ll get soil compaction and too much rooting with such a small area. I would suggest an eighth to quarter acre or so if it is done with four to six managed intensive rotational grazing paddocks. Depending on the season and the quality of the pasture you may or may not need extra feed.

As I mentioned before, our pasture is running at about it’s carrying capacity right now. This is because we have fairly poor, acidic, low quality, thin mountain soils. Things are getting better. As we lime the soil it increases the pH which improves the growing conditions for grasses and legumes like alfalfa and clover. As the pigs graze they are also pooping and urinating which spreads fertilizer over the fields. The whey and other good food they eat gets turned into pork but also about 75% of it passes through them and gets excreted adding to the fertility of our soils. In time our soils will improve. If you have rich soils and good pasture you can probably have a higher density of livestock than we can.

Of interest: In concentrated feeding operations (CFOs a.k.a. Factory Farms a.k.a. the Evil Dark Lords of food production) they allow that the “generally accepted space per pig during finishing is 8 square feet. That is a 2′ x 4′ closet. The average finisher pig is about 4′ x 1′ x 18″. Modern office cubicle workers are allowed slightly more at a typical 5′ x 5′ or 25 square-feet per worker (averaging 5′ 9″ x 14″ x 14″). Our tiny cottage is 252 sq-ft for the five of us or about 50 sq-ft per person. Fortunately, we, like our pigs, don’t spend our lives indoors all the time and we have shared spaces. Unlike the pigs, we monkeys make use of vertical spaces too. :-)

Realize that 75% to 80% of the time, at least 21 days and preferably 30 days per grazing cycle, the land is resting and re-growing. The livestock are only on a section of field for a short period and then they move on to greener pastures. When we move pigs we truly are taking them to a better place.

You might also be interested in the article South Weaning Paddock which describes a weaning setup that is 100’x100′ divided into ten paddocks. That’s a quarter acre and large enough to raise two or three pigs all the way to finisher size using the managed rotational grazing. It is an example of doing it on a very tiny scale.

Some Related Reading:
One Day of Rotational Grazing
How Much Land Per Pig
Pasture Post Pig Grazing
InstaPigs and Animal Units
North Home Field Sow and Piglets
Sugar Mountain Farm Pigs: Feeding and Grazing
Vet Visit Field Tour
Painted Probed & Pierced Pigs
Sorting and Driving Pigs

On a totally different topic, I had an interesting temperature reading today
on the tiny cottage. The temperature is normally in the mid-60’s to low-70’s F which is due to the massive nature of the concrete and stone construction (100,000 lbs). Today the tiny cottage high was 55°F and the low was 53°F. Admittedly we haven’t had any sun for a few days but that seemed oddly low. Then I discovered that I had left the bathroom window open for two days and nights… Oops. I had been ventilating after using silicone. What is amazing is that the outdoor temperature dropped to 38°F and the tiny cottage still only went down to 53°F. Pretty good for an unheated shell.

Thursday-Friday Outdoors: 57°F/38°F Overcast, 4″ rain, high winds
Farm House: 68°F/63°F
Tiny Cottage: 55°F/53°F Window left open over night, attic forms work

About Walter Jeffries

Tinker, Tailor...
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110 Responses to How Much Land per Pig?

  1. Jonathan says:

    Hi Walter,
    I got here via a link you posted on the Pastured Pigs group on Facebook. I’m planning to move to the country and homestead soon. In another post you mentioned a fairly low number for income. I’m not sure I understand the numbers correctly.

    These are some deliberately round #s – I’m just trying to hit within 20%:
    10 pigs per acre x 20 acres (I don’t know how big your place is) x 150# meat per pig (at a slaughter weight of around 200#) x $4.00 per lb (sell for $6 avg, $2/lb processing) x 75% (because you keep 25% for breeding = $90,000 per year minus delivery costs.

    Doing your own breeding, and feeding the animals from the land + free dairy waste, I don’t see a lot of input costs that would alter this number by a significant amount. What am I missing?

    • Capital investment to start with. I was given nothing. I bought my own land, tractors, trucks, fencing, concrete/insulation/wire to build the butcher shop, building roads so the whey can be delivered and maintaining them, stone, sand, CMA, labels, gasoline, diesel, seed, pipe, connectors, valves, tanks, troughs, pliers, hammers, shovels, rakes, chainsaws, chains, etc. Then you must also pay the tax man, the butcher, the banker, the baker, the candle stick maker (electric/phone), etc. I would suggest doing a full fledged business plan and then be prepared to revise it as you learn. There are a lot of non-obvious costs which you’ll discover after a few years. You may also discover that the sell yield numbers you cited above are high – if you’re selling wholesale or retail then there is a considerable amount of the pig that does not get you paid for so adjust downward.

  2. T. Foerster says:

    Thanks for all the information. I have one question-
    You’ve mentioned that you feed your pigs whey for extra lysine, and you recommend other people to feed their pastured pigs some sort of milk product. I was wondering if clovers, alfalfa, or some other high protein feed would do the job well enough.

    • It doesn’t have to be dairy – there are other things such as eggs, meat, blood which are also good sources of protein. Clovers, alfalfa and other legumes we plant in our pastures to suck nitrogen from the air and produce protein. The issues are there are many different proteins, specifically amino acids, and on pasture lysine is limiting, thus the dairy which happens to be something we have as a resource to augment pasture for faster growth.

      • T. Foerster says:

        Thanks for answering. I have come up with a few more questions if you don’t mind. I understand you may not be familiar with all of them, so if you don’t know that’s fine.

        1. Correct me if I’m wrong but you would basically say that other than perhaps soybean meal, there are no North American plants, including root crops or tree leaves, that would provide adequate lysine without getting a very high crude protein diet.

        2. According to this table fish meal, blood meal, and meat and bone meal all have high lysine levels, as you said. Do you have much experience feeding them, and how would you feed them in a pasture based diet?

        3. One more question, how do you feed minerals such as salt?
        Thanks again

        • Hmm… No, I would not say that. I don’t know all the plants. I also would not limit myself to native North American plants.

          I’ve never fed fish meal, blood meal, meat nor bone meal. They are older traditional foods that are used for pigs in some countries which I have read about. The fish meal can be a problem with producing a fishy taste from what I’ve read in many articles. Feed for flavor.

          There is also confusion often with people trying to formulate diets and feed in that they think the pig needs to eat exactly the right amounts of things. This is not the case. The exact formulation of diets comes out of confinement feeding operations where feed is concentrated and designed to maximize return on investment, growth rate, etc. Out on pasture things are a lot more relaxed. The animal simply eats more to achieve the minimums. That is what the term “limiting protein” is all about.

          Salt is pretty dangerous for pigs – it can cause salt sickness – so be careful feeding high salt feeds. For minerals we mostly use our soil and in the winter we often feed kelp. See the article Mineral Deficiencies.

  3. Jon F says:

    I was curious as to how you market your meat. Obviously you can get a lot more for it as retail cuts, but having a stable base of customer(restaurants and whatnot) is preferred. We are new to pigs and this is the only obstacle we can see, the selling of the finished product. We’d like to get as much return per pig as possible, and from what we’ve calculated, an entire pig after being butchered and packaged can sell for a total around $1200 or even more in our area…but again, selling small scale retail is more tedious and time consuming. We are wanting to get to the point where we are doing 250-300 pigs per year, starting with just 60 the first year as a trial but are not wanted to be at less than $1000 per pig after being butchered. Obviously less if sold as a whole or half. Thanks in advance for any advice!!

    • We get the maximum dollar per pig retail but the easiest sale at wholesale. Whole pig orders are between the two. Weekly wholesale standing orders from local stores and restaurants are our bred and butter followed by whole pig orders and very distantly followed by retail which only makes up a few percentage points of our annual sales. I like consistency. I need to pay the bills each month.

      • Jon F says:

        Thanks for the info. How do you market to the restaurants and such? How do you price it for them? And my biggest obstacle I think is convincing them to switch from their current supplier…obviously quality and breed of pig would come in to play. I just can’t figure how to approach the buyer for the restaurant and convince them to go with us while still making a decent profit.

        • See the Wholesale Page and the Literature Page for details and our brochure. The wholesale buyers commit to purchasing large standing orders weekly or bi-weekly and accept that we fill the order as available. Priority develops with how long they’ve been buying. This means new places start out lower on the hog. There’s only two tenderloins on a pig but demand for ten per pig. In return for the consistent standing orders they get a discount of about 30% to 50% of of the retail cuts price you see on the Lit page. The whole pig price is already volume priced so no discount there. What the stores and restaurants need is quality, consistent supply, delivery and professionalism. It is a big jump for a small farm to get to the level where they can supply the volume required – that is one of the hurdles.

  4. Andrew says:

    Hi Walter,
    Great information. I’ve got a couple of questions:
    1. In a few comments you mention you get three litters per year. Do you breed them as soon as they farrow? Because 3 months, 3 weeks, 3 days comes out to 342 days meaning they’re not pregnant for 23 days total?
    2. If you feed 2.5 gallons of milk per hundred weight per day that comes to 66250 gallons of milk per year at least. Do you just lug out the milk in 5 gallon pails? If we fed raw milk out of the bulktank that would come out to well over $1.5 million that could be sold into the milk market. How much do you pay for the whey and buttermilk?

    • Three litters per year from a fair number of sows in the Blackieline. Around 2.5 litters per year is more normal. They do their own breeding and breed back quickly while still nursing. They also short gestate by a week to two weeks.

      It’s 3.5 gallons per hundred weight of pig per day. We use 1,000 gallon tanks piped to troughs. We don’t pay for milk or whey, we provide a service to the dairy by getting rid of what they are not allowed to otherwise dispose of.

  5. Sean Govan says:

    This article has interesting insights on how many total pigs can be supported per acre. But with your management and your soil, how many finishers could you produce per year per acre on just whey and pasture? How many finishers per year per acre could you produce on pasture alone?

    • It all depends on how much you want to supplement. Without any supplementing I find I can raise 10 pigs per acre doing good managed rotational grazing with our forages with our genetics in our climate for our season length. I’ve measured this in a number of different ways and each time come back to approximately the same measure of 23 sq-ft of pasture per hundred weight of pig per day. Given that I think 10 is a good safe number without supplemental feed. If you’re just starting out I would suggest half that number. If you have supplemental feed you could double or quadruple that number quite easily, thus reducing the percent of pasture in the pigs’ diet. Whey is an example of a supplement. Milk is a supplement. Cheese is a supplement. Spent barley, apple pomace, corn, soy are all supplements you can add to their diet to either speed up growth or increase the number of pigs per acre, or both. Grain is not evil, just expensive.

  6. Sean Govan says:

    Just to clarify my last comment, I meant how many finishers per acre per year, taking into account that you must also have enough pasture to continue feeding your breeders.

  7. Thomas Rainier T. Saballa says:

    Hi, i was just wonderìng, if you still vaccinate or deworm the pigs, what are pigs’ maintenance protocol? I have 80 hectares of of land, are there any starter manuals for free range pigs to get? From day 1 to 90?

    • Pasturing patterning protocols prevent primary parasite problems. After that chickens, hard winters, copper in the soil, good heathy stock genetics and when you’re bringing in new stock do full quarantine with vaccinations and double deworming. I am a firm believer in vaccinations as good preventative medicine.

  8. Stephen says:

    Hello Walter,
    Thank you for taking the time to answer all these questions. I have found your site an invaluable source of information and am grateful for your willingness to share.
    I am wondering if you might be willing to share more about your experience with grazing sheep with pigs. How it might have differed from having paddocks with just pigs, and poultry. I assume fencing was more extensive. I am especially curious how it pertained to carrying capacity. Going with the rate of 10 pigs per acre how does adding sheep effect that number? is there something you figure on like 1 sheep per pig cut the rate in half, less or more? did you increase paddock sizes or move frequencies? Anything you are willing to share from your experience is greatly appreciated.
    thank you.

    • The big issues with grazing sheep with pigs are:

      1. Separate at lambing time until the lams are up and running – say a week or so. A new born lamb is too interesting and pigs will come over to it, nudge it, when it doesn’t object they’ll then bit it and from there things go downhill.

      2. During mud season separate the pigs and sheep or you’ll have muddy wool.

      3. Sheep need to not have access to some supplements you may be feeding pigs like butter in hay pack as it will upset their rumen.

      Other than that the sheep and pigs make great co-grazers. They eat slightly differently. And if you put the bottom wire on the fence high then the sheep graze under the fence to keep the weeds off the hot wires.

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