Nutrient Density Profiles for Conventional vs Pasture-Raised Pork

Project Overview

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

Information Products


  • Animals: swine


  • Animal Production: animal protection and health, feed/forage, feed formulation, feed management, feed rations, free-range, grazing management, heritage breeds, range improvement, rangeland/pasture management, stocking rate
  • Crop Production: cover crops
  • Education and Training: farmer to farmer, on-farm/ranch research
  • Farm Business Management: apprentice/intern training, cooperatives, feasibility study, new enterprise development
  • Sustainable Communities: values-based supply chains


    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. 
    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.