Experimenting with Forage Options for Pastured Pigs

Reader Contribution by John Arbuckle and Singing Pastures
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What can pigs eat? This farm sets out to find the answers.

Everybody has (or should have) something that really makes them feel alive — some topic or calling that gets them unreasonably excited. At Singing Pastures Farm, that topic is “How much grass can a pig eat?”

I use the term “grass” loosely. By grass, I generally mean forages. (Many people do not realize it, but this loose definition is also applied to grassfed cows that are fed all manner of forages, including, but not limited to, clover, alfalfa, and broad-leaf forages.)

Types of Forage for Pastured Pigs

So, how about pigs? What can they eat? Here are some of the things on the menu: broadleaf forages, like lamb’s quarter and pigweed. Brassicas, such as kale and turnips. Legumes, such as clovers and the vegetative bodies of pea and bean plants. And of course, grasses themselves, whether they are perennial, cool-season grasses like timothy, orchardgrass and fescue, or the common annual crop grasses, like oats or sorghum-sudangrass.

At Singing Pastures Farm, we strive to make these the foundation of our pork production. To be sure there always has to be more involved than just forage, but these forages represent the most heavily utilized resource option in our research on pigs.

The Pig Forage Experiment

We set out this summer (2017) to document the nuts and bolts of feeding forages to pigs. Thanks to a grant from Sustainable Agriculture and Research Education (SARE) and our friends at Practical Farmers of Iowa, we are going to be able to offer the results of our research by the end of the year. We are recording data on three separate groups this summer.

The control group: Pasture raised pigs on a full grain ration. These pigs receive a standard ration of 100% non-GMO grain, based on weight and age. This grain is a balanced ration of 16% protein from our local feed mill. They are kept in paddocks of about an acre and moved at least twice a month, sometimes more. They eat some grass and clover and benefit from it.  However, it is not contributing tremendously to their rate of weight gain. These pigs were born on our farm and are Red Wattle, Hereford, Hampshire crosses.

Experiment group #1: Pasture-raised pigs on a 50% reduced non-GMO grain ration. Because the growth curve for young, growing pigs rises so steeply relative to grain intake during the first 10 weeks of life, we elected to keep them on the fully prescribed ration until that time. This will put the pigs at about 3 pounds of grain per pig per day by 10 weeks. Rather than increase their ration as they continue to grow, we maintain 3 pounds per pig per day for the rest of their life. In this, they should  receive roughly 50% the total amount of grain usually required by the time of their harvest date (around 7 months of age).

It should also be noted that 40% of a pig’s allotted ration is required for maintenance. This means that 40% of their feed is used just for basic body functions, like maintaining body temperature, respiration, heartbeat, and movement. So, when you reduce a pig’s grain ration by some amount, you must increase the availability of some other resource to the same extent.  Failing to do this will increase the days to maturity as it will take the pigs significantly longer to reach their target weight. That prolonged days to maturity may increase the total quantity of grain consumed so much that it surpasses that of a pig on a full grain ration for fewer days!

We offer our 50%-grain group oceanic quantities of our spring annual mix (forage peas, dwarf essex rapeseed, and forage oats.) These pigs are also from our farm and are are Red Wattle, Hereford, Hampshire crosses.

Experiment Groups #2: Pasture raised pigs that are grain free. This is our most radical experiment in alternative pork production. This group has never tasted grain and consumes tremendous quantities of our spring annual mix. They are supplemented with acorns, which we gathered last fall and a small quantity of organic milk powder. This batch of pigs was purchased at about 10 weeks of age from a farm in Nebraska. Their ancestry is of mixed parentage including Hereford and Large Black.

Experiment Group #3: Pasture raised pigs that are grain free. This is a second group of grain-free pigs, with the same management plan as the previous experiment group, but of a different heritage. These pigs are from Sugar Mountain Farm in West Topsharm, VT. (We will be writing a follow-up blog about Walter Jeffries and Sugar Mountain Farm next month.)

There is something special about our no-grain groups that makes these experiment groups possible. Both of our no-grain groups are from farms that have selected breeding stock for a high fiber diet for upwards of 15 years. They are able to consume large quantities of forage and gain in body mass as a result.

My homegrown, pasture raised pigs that we are using for the full grain and 50% reduced grain groups, do not have this quality to same extent. I mention this as a cautionary statement: Don’t go out and buy 12 heritage-breed pigs, put them out on stemmy fescue, and expect them to grow without some grain. It won’t work. Just like in grassfed beef, genetics matter.

The chief difference here is that in pigs, those genetic qualities are exceedingly rare. Finding a farmer with the time and motivation to manage pigs for grass finishing are equally so. Currently I am only familiar with three farms nationwide that do this with pigs. Bear in mind that feeding grain to pigs is not a bad thing in many systems. If your local farmer feeds grain to his pigs, awesome! Be glad you have a farmer raising pigs!

There are a million and one ways to raise a pig. Your local farmer needs to take into account his or her local resources and time constraints.

As the summer progresses, we will be recording data on forage quality and quantity, pig growth and if the opportunity pops up to offer some other resource (pumpkins, apples, unsalable farmers market tomatoes etc). We hope that we can shed some light on the techniques that make grass finishing a pig timely, profitable, and humane. That is part of our calling here at Singing Pastures Farm. We hope that you also pursue your calling, whatever it is, in a precise and passionate way.


John Arbuckle aims to change the trajectory of modern pig farming at Singing Pastures by demonstrating that a thinly wooded pasture, when managed well, can sequester tons of carbon, support lots of family farmers, create the most nutritionally dense pork and nurture an army of coyotes, owls, frogs, worms, bobcats and happy children. Read all of John’s MOTHER EARTH NEWS posts here.

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