Nutrient Density Profiles for Conventional vs Pasture-Raised Pork

Final report for FNC17-1067

Project Type: Farmer/Rancher
Funds awarded in 2017: $7,183.00
Projected End Date: 01/30/2019
Grant Recipient: Singing Prairie Farm
Region: North Central
State: Missouri
Project Coordinator:
Holly and John Arbuckle
Singing Prairie farm, DBA Singing Pastures
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Project Information

Description of operation:

John and Holly Arbuckle own Singing Prairie Farm formerly in La Plata, MO, now in Newcastle, ME. It is a non-GMO, pasture-based farm focusing on hog production. In 2017 they raised about 150 pigs a year for direct sale and for their value-added snack product, Roam Sticks. ( They are currently expanding to 300 finished pigs a year at their new location.

John is a ninth generation farmer and has a degree in Sustainable Agriculture from Fort Lewis College in Durango, Colorado. His farm ventures have included pasture-raised chickens, turkeys and pigs. He farmed from 2010-2018 in Missouri, and has recently relocated to a 200 acre ex-dairy farm in Maine. They currently raise chickens, pigs and custom graze cows on their new farm. John and Holly are a Savory Hub farm candidate, and expect to be the first Savory Hub in Maine by summer 2018.

In 2012 he received a SARE Grant comparing nutrient density and cost of production of eggs from laying hens on full and reduced grain rations. He spoke on this topic at the Mother Earth News Fair in Seven Springs, PA and has continued to be a speaker at Mother Earth News Fairs. His presentation, "How Much Forage Can a Pig Eat?" was well received at the Mother Earth News Fairs in West Bend, WI and Topeka, KS in 2016. John recently had an article published in Permaculture Magazine regarding his work using high octane forage combinations (often used for dairy cows) for grazing pigs.


In recent years, there has been a significant jump in sales for grass fed beef due to the research and promotion of its increased nutritional benefits vs conventional. These benefits justify a higher price for the farmer. The same research needs to be done for pigs. An important component of this research is to not only see if pasture-raised pork is nutritionally superior to conventional, but also if there are additional nutritional benefits to human health by increasing the green matter pigs consume from cover crops, clover and grasses.

Even though pigs are monogastric and can not be strictly "grass fed", it is possible to significantly reduce grain consumption by increasing forage consumption and feeding milk powder. For the past several years, John has been growing high octane forage crops for grazing pigs, as well as feeding waste produce. Initial results have demonstrated a reduced cost for feed, as well as an increase in nutrient density of the pork. John used pigs from two other farms where they have spent years selecting for the appropriate genetics for weight gain on low or no-grain rations. More research is needed to help substantiate the initial findings of increased nutritional value.

Selecting for appropriate genetics in grass finished beef is vital to obtain effective weight gain. Similarly, we sought the best genetics available for forage-fed pigs.

Sugar Mountain Farm in Vermont has been raising grain-free pigs for many years and selected for weight gain on a ration of whey, grass, and hay. They were used for the grain-free experiment group. In addition, the grain-free group included pigs from Clear Creek Organics Farm in Nebraska. These pigs were also selected for their ability to gain weight on a forage-based diet. They were supplemented with organic milk powder to provide the limiting amino acid of lysine.

The 50% reduced grain group were Hereford/Hampshire cross from Singing Prairie Farm. They were provided with forages, but did not receive milk powder.

The full ration group were Hereford/Hampshire cross, from Singing Prairie Farm.

For the nutrient density profile on conventional pork, we bought pork chops from a grocery store.

The experiment began in June when the pigs were all about 8 weeks old; there were 17 pigs in the no-grain group, 8 in the 50% reduced grain group, 50 in the full grain on pasture group. The zero grain group and 50% reduced grain group had their runs expanded to offer fresh forage daily. The full grain group was rotated every 7 days.

Pork samples were sent to Clemson University from each sample group, as well as a pork chop from a conventional factory farm. Generally speaking, pork is considered to have an Omega 6:3 ratio of 30:1. By increasing grazing, we determined that rotating pigs on pasture, raises the Omega 3s of the meat, even with full grain consumption. (See results in Education Section). Further research is needed with a larger sample size (50 pigs per group) to replicate this study to be statistically significant for colleges and universities.

Project Objectives:
  • To compare nutrient density profiles of Omega 6:3 ratios of pork from conventionally raised pigs and forage-raised pigs on full grain, 50% reduced grain and grain-free rations.
  • To increase profitability for farmers of pasture-raised pork by demonstrating its nutritional benefits and justifying its higher price.
  • To reduce the negative environmental impacts associated with industrial pig farms such as water and air contamination, by supporting the pasture-raised pork market. 


Click linked name(s) to expand/collapse or show everyone's info
  • Susan Duckett (Researcher)


Materials and methods:

Grass fed beef has receive tremendous and well deserved attention in the last 10 years. To quantify that statement we see that between 2011 and 2016 grass fed beef sales skyrocketed from 11 million dollars to 256 million dollars. In this, we infer that the demographic responsible for these sales is interested in: increased nutrition, animal welfare and sustainability issues that may also apply to pasture-raised pork.

Our goal in conducting this study is to dig a little deeper into the nitty, gritty of the benefits of raising pigs on pasture. This includes:

  1. Cost/benefit analysis: Expenses vs rate of gain
  2. Labor involved
  3. Nutrient density of final sellable product

We looked at 3 groups of pigs:

  1. Hogs on pasture on full grain rations
  2. Hogs with 50% reduced grain rations
  3. Hogs with zero grain rations

In compiling these numbers we hope to offer other ecologically sensitive family farmers information that helps them achieve greater sustainability, profitability and comfort.

Full Grain Group

This is the model people commonly think of as pasture-raised. These pigs were born between April 12-22. There were 50 in this group. At 7 weeks we weaned them and rotated the sows into the woods immediately for re-breeding. The young pigs were left in their familiar terrain for 7 more days before being rotated onto open prairie for the summer. Young pigs noses were rung after weaning to encourage grazing and discourage breaking up the ground. Their management was as follows:

  • Run size was variable depending on pig size and weather. It was estimated to be enough ground to receive positive impact for 7 days.
  • Run size grew as the pigs grew. Full grain pigs were fed a prescribed amount of grain twice per day and waterers were refilled at the same time.
  • Feeders were moved to a clean spot twice per day so as to avoid ruining the sod around them. Hutches were moved every 24 hours for the same reason.
  • During wet weather staw was added to the hutches.
  • When hot weather came the 6 x 8 metal quonset style hutches were replaced with a 20 x 30 foot home built shade structure. This structure was a large metal frame, built on a disassembled hay wagon. It worked wonderfully. We continued this management structure all summer long.
  • Seven days between rotation, the shade structure was moved every 24 hours, feeders were moved every 12 hours. The waterer was placed on top of salvaged plywood to protect the area, and moved every 7 days.

All of these strategies combined create a plan that will leave a paddock with between 95-100% intact sod ground cover.


50% Reduced Grain Ration Group

These pigs were half sibling to the pigs in the full grain group. Same boar, different sow. She was a full sister of the sows who gave birth to the full grain pigs. Because of the quick growth of the young pigs we felt it best to not commence the grain reduction until the 12th week. This allowed them to get a good start and build growth momentum in the right direction before asking them to make gains from reduced grain/increased forage rations. During this time, these pigs were kept on highly palatable and nutritious stands of orchard grass and timothy with high concentrations of red clover and some annual forages (spring forage mix). In this we hoped to be preparing them for what was to come.

At the 12th week, we halted the standard increase in grain we had been giving them every week, ie. for the rest of their lives, grain did not increase. We did increase the availability of forages.

Zero Grain Pigs

With this group we find our most radical departure from modern pig farming. We have long heard the words, “since pigs do not have a rumen, they can’t get much benefit from eating grass”. In most cases that is the truth. Most modern pigs have been selected for growth in a world of “cheap” grain for so long that the statement has become an economic institution. The fact remains that some pigs can graze to a high level and all pigs benefit from grazing a little. With proper management you can nearly double your grass yields for hay or beef cows by allowing pigs to impact and fertilize those pastures for the next year.

The pigs in the zero grain group were raised under the same management style as the 50% reduced grain group but with 2 major exceptions. The first is that they had different genetics. We wanted to jump start our zero grain pigs with the best genetics for grazing. We sought out farms who raise pigs under low- to no-grain management systems. One was in Nebraska, the other in Vermont. Second, through our studies we have learned that the first limiting amino acid in pork production is lysine. In the modern world, farmers use roasted soybean meal to serve this need. We made use of organic, nonfat dry milk powder to get the necessary lysine. (Full fat would have been preferred, but it was cost prohibitive.)

Research results and discussion:

Conventional Pork: We used a store bought pork chop as the "standard" for Omega 6:3 ratios. In the literature, pork is considered to have an Omega 6:3 ratio of 30:1. The pork chop we submitted for testing was 29.4:1

Full Grain Group: They essentially were living on non-GMO grain, eating small amounts of grass. While the quantity of pasture they consumed is not enough to offset their feed expense noticeably, it does make their meat more nutritious and the rotation process excludes them from pathogens that may otherwise slow their rate of gain. Additionally, pasture-raised pigs are an incredible boon for grass production. This is important because most pasture based pig producers also raise cattle. 

Based on our findings the full grain pigs produced the most meat, the fastest meat, and the cheapest meat. This is an advantage in many systems. Luckily, that is not the only market presented to independent hog producers and many diverse markets may favor slower growing, more nutrient-dense meat with a more colorful story.

It should also be noted that this large and fast growing management strategy will only maintain the economic advantages we currently see in a world of cheap petroleum and cheaper, heavily subsidized corn.  Should one of those variables change in the next 30 years, we may see economic advantages to a more forage based diet.

Full Grain Statistics
Born: 4/21/2017
Died: 12/11/2017
Days Between: 234 (7 months, 20 days)
Grain Consumption: 844 lbs of grain per pig
Grain Cost: $143.48

Pig Live Weight /Hanging /+ Processing Fee
1. 272.5 /196 /45 + 133.28 = 178.28
2. 263.5 /189 /45 + 128.52 = 173.52
3. 282 /203.5 /45 + 138.38 = 183.38
4. 265 /190.5 /45 + 129.54 = 174.54
Total: 1083 /778.5 /$709.72
Average: 270.75 /194.63 /$177.43

Cost of Production and Processing
Feed Cost $ 143.48
Transportation $ 6.13
Infrastructure $ 35.00
Processing $ 177.43
Total: $ 362.04
Average Daily Gain
270.75 (average live weight) DOE (234) = 1.1570 lbs per day average gain
Average Cost
$362.04 (average production and processing cost) DOE average live weight (270.75) = $1.3371/lb. (or, $1.5470 per day per pig)
So, it cost us $1.3371 for each pound we successfully put on the full grain pigs.

50% Group

The 50% group consumed about 54.8% of the grain that the full grain group consumed. It should be noted that they lived 32 fewer days. So the title "50% group" is actually a misnomer. (We decided to stick with the original group name since it conveys the general sentiment of the experiment, which is to monitor performance of a pig with a restricted grain intake and a largely unrestricted opportunity to consume high quality forage.)  This group did perform well; they were able to consume large quantities of high octane forages and were still able to achieve an acceptable rate of gain, while reducing overall cost and creating nutritionally superior pork. It is our belief that a 50% reduced grain ration would work best for farmers trying to reduce overall feed cost, while justifying a higher price point for pork.  

50% Group
Born: 3/22/2017
Died: 10/10/2017
Days Between: 202 (6 months,
18 days)
Grain Consumption: 463 lbs of grain per pig
Grain Cost: $78.71
Seed Cost: $11.96
Salt Cost: $0.90
Total feed cost: $91.57
Pig Live Weight /Hanging Weight/ Processing Fee
1. 216 /155.5 /45 + 105.74 = $150.74
2. 197 /141.5 /45 + 96.22 = $141.22
3. 195 /140 /45 + 95.20 = $140.20
4. 161 /116 /45 + 78.88 = $123.88
5. 140 /99.5 /45 + 67.66 = $112.66
6. 197 /142 /45 + 96.56 = $141.56
7. 215 /154 /45 +104.72 = $149.72
8. 193 /138 /45 + 85.56 = $130.56
Totals 1,514 /1,086.50 /$1,090.54
Average 189.25 /135.81 /$136.32

Cost of Production and Processing
Feed Cost $ 91.57
Transportation $ 6.13
Infrastructure $ 35.00
Processing $ 136.32
Total: $ 269.02
Average Daily Gain
189.25 (average live weight) DOE (202) = 0.9368 lbs per day average daily gain
Average Cost
$269.02 (average production and processing cost) DOE average live weight (189.25) = $1.4215/lb. ($1.3316 per day per pig)
So, it cost us $1.4215 for each pound of weight achieved by 50% grain pigs.

No grain group

This name also ended up being something of a misnomer as the pigs did consume some grain in the form of immature peas (still on the vine) toward the end of the spring grazing season. They also might have consumed some sorghum/sudan seeds from mature plants towards the end of the summer growing season. We did not observe the latter, but it is possible. At any rate, there was so few of those seed heads that it is doubtful whether it would have benefited them much.  This group represented our most radical departure from the norm of pork production.  The first limiting amino acid in pork production is lysine. Lysine is not present in meaningful quantities in forage. Also, lacking a rumen, the pigs are not able to synthesize lysine from its components and therefore must be given that resource in appropriate quantities. For us, the most cost effective product that could serve as a vehicle to carry lysine was dry, fat free, milk powder.  We would have prefered full fat but that was unavailable at a reasonable price point.  We choose this as compared to whey from a cheese house for a variety of reasons.  

  1.  It is much easier to handle.
  2.  It is much more storable/higher shelf life.
  3.  More nutrient dense.
  4.  This product was organic rather than conventional as the whey would have been.
  5.  The facility which gave away free whey was 70 miles away. When it takes all day and a lot of gas to get free whey, that may go rancid on a hot day, it ceases to be a cheap resource.

That said, the expense of the milk powder is the single biggest detriment in this strategy being more replicable. Because of the $188 of milk powder, per pig, that went into the experiment, we feel that most producers will not have customers willing to cross the threshold necessary to make no grain pork a common food product.  If on the other hand, a pig farmer lived close to a cheese house and could access the whey in convenient fashion, grain free/grazing pigs would become more possible for that individual.  It is our experience over the years that a little waste dairy product and a LOT of something else will grow a good pig. That something else can be about anything: clover, old sweet corn, pea vines, potato peels, peanuts, pumpkins, turnips, apples, acorns, bakery waste, high quality vegetative grass etc.  You name it. With a little milk of some variety, a pig can make a living on it and grow at a meaningful speed and to a meaningful size.

As mentioned earlier, this group was the most expensive to put weight on.  Going into this experiment we realized that some individuals would not thrive (grow).  We ascertained this from speaking with a few other farmers who regularly raised pigs in similar ways.  The general consensus was that about 40-50% of the individuals would fail to grow well.  In this Natural Selection exercised a rather heavy hand.  About 5.5 months in we could see that 8 individuals did not appear to be thriving.  On the contrary, they were doing poorly.  They were removed and harvested.  As they were such unsalable outliers, their statistics do not appear in the following report.

Participation Summary
2 Farmers participating in research

Educational & Outreach Activities

20 Consultations
1 On-farm demonstrations
6 Published press articles, newsletters
6 Tours
2 Webinars / talks / presentations
1 Workshop field days

Participation Summary:

25 Farmers participated
6 Ag professionals participated
Education/outreach description:

Our mission statement as a farm is to "fill the country side with eco-logically sensitive, pasture based, family farmers".  Our on-farm research is done to facilitate that mission.  Hence, this project was undertaken to demonstrate the feasibility of three different feed management systems and their pros/cons.  We hope that farmers who read this study will have a greater understanding of what happens when you restrict the consumption of annual cereal grains in pork productions.

To that end we have chosen to share our results in many ways.

  1.  Speaking at conferences.
  2. Writing essays for green culture bloggers.
  3. Leading farm tours for our Amish neighbors.
  4. Working with Practical Farmers of Iowa to create a document which can be published on line and in hard copy.
  5. Publishing our findings in Mother Earth News magazine.
  6. Publishing our findings in other more main stream farming Journals.


Learning Outcomes

5 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
Lessons Learned:

Our project was designed to 1) Determine if increasing pasture and forage crops led to an increase in Omega 3s and 2) Help evaluate if this is economically viable for farmers.

To our first point, we sent meat samples to Clemson University for evaluation. Here are the Omega 6:3 ratios. The higher the Omega 3s, the better for nutrition, and consequently marketing:

  • Conventional (factory farmed) pork ratio was 29.4: 1
  • Full grain pigs/rotationally grazed on pasture was 13.84: 1
  • 50% reduced grain/heavily grazed through forage crops was 9.89: 1 (for the males) and 9.87: 1 (for the females)
  • No grain pigs/heavily grazed through forage crops was 5.15:1

This indicates that compared to conventional pork:

  • Full grain/rotationally grazed on pasture pork is 52.93% higher than conventional.
  • 50% reduced grain/pasture + forage crops is 66.39% higher than conventional.
  • No grain/pasture + forage crops is 82.48% higher than conventional.

We found that the 50% reduced grain pigs and no grain pigs grew slower than the full grain pigs. Whether this is economically viable, or not, for the farmer is determined by if the farmer can command a higher price point because of the increased Omega 3s. If a farm has a cheese making operation, and a nearly unlimited supply of waste whey (from cheese processing) this could be a great market opportunity. However, if you are competing with grocery store prices, reduced grain pork will not be viable because of the slower growth of the the animals. In most real world commercial scale operations, grain reduction is a losing proposition.  However, even with full grain pigs, rotated on pasture, showed significant gains in Omega 3s. In our opinion, this is our most important finding in this study.

Practical Farmers of Iowa (PFI) is writing up a publication on this study for other farmers. It will be shared online on their website, and in hard copy when they visit trade shows. In addition, John will be on a podcast with PFI in February. For this study, they are our main portal for sharing our findings. In addition, John and Holly are writing articles for Graze magazine and have talked about their findings in some of those articles.

Project Outcomes

2 New working collaborations
Success stories:

Our research has led us to begin the process of becoming the first Savory Hub farm for pigs. At this point, the Savory Hub farms are all focused on beef or sheep production. They are interested in our pursuit of how pigs can utilize holistic grazing strategies. We use strategies to minimize aggressive rooting and exposed dirt, such as humane certified nose rings, multiple moves of feeders per day, and moving the pigs every few days, depending on the weather.

As a Savory Hub farm with a focus on pigs, we will be able to network with other hub farms around the world to disseminate the research we do on how to integrate pigs into the field of regenerative agriculture.


In order to make our results statistically significant, we need to use larger sample sizes. In the future, we would like to do a study with at least 50 pigs in each group. We would definitely have a group of full grain pigs rotated on pasture again. We would likely do a group with reduced grain consumption, but we would likely shoot for a more moderate reduction like 20%. 

Information Products

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.