Can Feeder Pigs Live On Grass Alone?

Keeping your feeder pigs on pasture means they are just eating grass, right? Actually, no! Most pigs are not just eating grass, they get feed, as well.

Most feeder pigs can not live on grass alone. Grass is difficult for younger pigs to digest and is low in energy, which means it will not supply the calories they need to grow well.

Feeder pigs are fast growers and fast growers need lots of high energy feed! Younger pigs are limited in the amount of grass or other forages they can digest compared to older pigs, like sows.

How Much Does It Cost To Raise A Pig will give you some estimates of what you’re getting into, including costs.

This limited digestion of forages is partly due to their digestive system’s ability and partly due to the high moisture level of grass.

Combine the relatively low calorie level of grass with the high calorie needs of a fast growing feeder pig and you have a mismatch. This is why feeder pigs can not live on grass alone.

Most feeder pigs need more calories than they can get from grass alone

Since grass is high in moisture, it is not calorie dense, especially if you are comparing grass (or other forages) to pig feed.

Pound for pound, there is significantly more available energy in your pig’s feed than there is in grass.

Pigs have a digestive system more like yours and mine, and I know I couldn’t live on grass!

Feeder pigs are not efficient at digesting grass

The “catch” regarding feeder pigs and forages (grass or any other plant material they would eat) is that their digestive system is not efficient at breaking down fibrous plant material.

Older pigs and adults, like sows, can do pretty well digesting grass, but it’s tough for young feeder pigs to get much nutrition out of grass.

Grains are easily broken down in the feeder pig’s digestive system, equaling more usable energy from grain when compared to grass.

Pastured pigs are eating grass and grain

While it’s true, pastured pigs have access to all of the grass they want, they are not living exclusively on grass.

They are also given access to all of the pig feed they want at the same time.

There is a notable exception, Sugar Mountain Farm, which is a pig farm in Vermont that uses no grain but feeds many other sources of calories, like whey, to supplement the grass.

Other than Sugar Mountain, everyone else that I know of raising pigs on pasture uses grain in addition to the pasture. I’m sure there are more exceptions, but overall the rule is to feed grain to pigs on pasture.

Pigs are eating 3-4 pounds of grass and 4-5 pounds of feed per day

In Forages For Swine, the amount of pasture eaten by pigs is 3 pounds (.75 pounds pasture on a dry matter basis) and 3.75 pounds of feed per day per 40-125 pound pig.

Once the pigs get a bit bigger, 125-240 pounds, they are each eating 4 pounds of pasture (1 pound on a dry matter basis) and 5 pounds of feed per day.

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Pasture grasses are 75-80% moisture, leaving 20-25% dry matter. I used 75% to calculate the pounds of grass listed above.

The 75-80% figure comes from this Michigan State University article, written by Jim Isleib.

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Pastured feeder pigs have and eat pig feed

No matter the size of the pigs, all of the feeder pigs are eating full feed. This means all of the ground feed they want to eat and unlimited fresh water everyday.

The great news is that raising pigs on grass, at least partially, gives them room to roam about and a way to keep themselves busy.

If you are planning ahead, having your pigs on grass also will give you a head start on working up some ground.

To be fair, the pigs will not be as thorough as a tiller, but they will turn some dirt!

If you haven’t run across this site before, Pasture Raised On Open Fields (PROOF), check it out. This an Australian site that has great information on raising animals on pasture, this article is pigs, specifically.

Feeder pigs can eat grass and legumes

Your feeder pigs can eat grass or other forages, like legumes. Be careful of letting them into something that you do not want rooted up.

How Many Pigs On 5 Acres? goes over a potential pasture rotation for you to set up with your pigs, even if you have a smaller amount of land, the idea is still the same.

All pigs will root up the soil

I have read about a few breeds that supposedly do not root, I’ve never seen a pig that didn’t root, at least a little.

Plan on some pig initiated soil disturbance any where the pigs are located. The amount of destruction is determined by how soft the soil is and how long you keep the pigs there.

If you want less rooting per area, move the pigs more frequently. Either way, expect some rooting!

Here is a great article Forages For Swine. It lists out all kinds of grasses and other forages and how well each plant works for pigs.

Feeder pigs can eat hay

I give my feeder pigs a bit of hay to eat and play around with. They won’t eat all of it, but I like to give them some interesting things to eat every few days to keep them happy.

Check out the video above, you’ll see our feeder pigs messing with their hay.

I don’t plan on the hay being a big part of their diet, it’s more of a snack. If they eat it all, I give more.

If they lay on it, I’ll skip it for a few days or try a different hay.

Feeder pigs can eat haylage

I give our pigs, younger pigs and adults, some haylage.

Haylage is fermented (wet) hay that I always think of as the livestock equivalent of sauerkraut.

The pigs eat the haylage just like they eat hay. They like to nibble around at it, since haylage provides something a bit different than their usual feed.

As far as the amount of haylage to give the pigs, go with a smaller amount and see how they do.

Remember, you are still feeding the majority grain, the forages are just snacks that keep the pigs busy chewing and add some interest to their day.

Feeder pigs will eat weeds

Your feeder pigs will also eat weeds. They are adventurous eaters and will taste test nearly anything.

The good news is they will try out all of the weeds you have, the bad news is the same! Make sure anything poisonous is not in the pasture to get nibbled on!

Feeder pigs will eat back brushy areas

The ideal place to put your pigs could be in a brushy area that is starting to look like it needs knocked back.

Of course, a fence of some sort will have to go up to keep the pigs in place!

Here’s a link to a Cornell pastured pigs presentation. It shows some of the places farmers that raise pigs are using for pasture and areas that the farmers are using the pigs to do some renovating.