Pigs on pasture: An assessment of pasture health, pork quality, and ecosystem rebound after rotational grazing

Project Overview

FNE16-859
Project Type: Farmer
Funds awarded in 2016: $14,752.00
Projected End Date: 04/15/2018
Grant Recipient: Hampshire College
Region: Northeast
State: Massachusetts
Project Leader:
Pete Solis
Hampshire College

Annual Reports

Commodities

  • Animals: swine

Practices

  • Animal Production: free-range, grazing management, pasture fertility, grazing - rotational
  • Production Systems: agroecosystems
  • Sustainable Communities: local and regional food systems

    Proposal summary:

        Access to pasture is thought to provide many benefits to raising hogs, including reducing feed/grain costs, better quality meat, and higher profitability. Our study will assess growth rates, grain consumption, and carcass quality of rotationally-grazed pigs relative to pigs on pasture without rotation. We will also examine the impact of hogs on pasture plant growth, re-growth, and soil quality, and explore ways to address pasture degradation and regeneration at the end of a grazing season. With an understanding of how pig grazing action affects a pasture not only in the current season, but also in the following season, a farmer can make good and thoughtful decisions about the best use of a piece of land. Our analysis will include: pasture and soil quality; carcass quality; average daily gain; and regrowth of pasture and soil quality in the following season. The experimental design we are using in the pasture allows for clear separation of the effects under study: rotation, reseeding, and their interactions. Outreach of the project will include a field demonstration and presentation at two separate NOFA summer conferences; a presentation at the PASA “Farming for the Future” conference; monthly updates on the Hampshire College Food, Farm, and Sustainability blog; a research report to Cornell Small Farms Quarterly (circulation 27,000); and an article to “On Pasture.”

    Project objectives from proposal:

    Access to pasture is thought to provide many benefits to raising hogs, including reducing feed/grain costs, better quality meat, and higher profitability. Our study will assess growth rates, grain consumption, and carcass quality of rotationally-grazed pigs relative to pigs on pasture, without rotation. We will also examine the impact of hogs on pasture plant growth, re-growth, and soil quality. In addition, we will explore ways to address pasture degradation and regeneration at the end of a grazing season.

    Methods

    Pig Procurement and Care: We will purchase a group of weaned piglets from the same farm. The males, if intact, will be castrated, and all piglets will receive an ear tag for individual identification. The piglets will be trained to electric fence for one week. Any medication given or other medical interventions will be documented.

    Experimental Layout: We will use a large pasture at Hampshire College farm, with uniform soil types. Fence lines will be maintained with mowing and string trimming. There will be three main experiment treatments: pigs in a rotational grazing system, pigs in a similar sized paddock with no rotational grazing, and a control without pigs for plant and soil comparisons. The control paddock with no pigs will be mowed periodically to prevent brush infiltration and to mimic general pasture care. To prevent massive pasture destruction at feeding and watering sites, feeders and drinkers will be moved frequently (see FNE16-859 Solis Appendix for experimental design images.)

    FNE16-859_Solis Appendix

    We are interested in using this field as a temporary pig pasture. Farmers may wish to use a field for pigs one year, cattle the next, or for hay, or for crops. With New England farmland at a premium, it is helpful that certain types of infrastructure are temporary.

    A schematic description of the experimental layout (for full details and map, see Appendix A). There are three systems: 1) four pigs in a field section rotated among three paddocks within the section; 2) four pigs ins a field section of comparable size with no paddocks or rotations; 3) a small section with no pigs at all (area comparable to a paddock) as a control for comparing plants and soil. In each section we will choose one half randomly to be re-seeded after pigs are removed (shaded), and the other half to leave as is. We currently plan three replicates of each system section (so 3 x (4+4) = 24 pigs total), randomly located in a two acre field (thus if we actually use 90% of the field, the section sizes with pigs will have them at a total density of ca. 16 pigs per acre).

    Sampling and analysis: We will examine four areas of interest, which are described below: 1) pasture and soil quality
    2) carcass quality
    3) average daily gain

    4) regrowth of pasture and soil quality in the following season

    1. Pasture and Soil Quality: We will collect samples for soil quality and pasture composition three times—prior to animals on pasture, at 3 months and after animals have been removed (approximately April, August, and October 2016). Composite soil samples (8 cores/sample) and pasture composition samples will be taken along the paddock lengths at 2 locations per paddock (Figure 1, Appendix A. Total=7 paddocks or sites in the non-paddock areas x 2 samples x 3 replicates x 3 dates=126 samples). Soils will be analyzed for the standard suite of agronomic parameters plus organic matter content. Pasture composition will be measured using square meter quadrats to assess plant diversity.

    2. Carcass Quality: We will work with Arion Thiboumery of Vermont Packinghouse to assess carcass quality of the 24 hogs in the study. He will look at depth of backfat at the 10th rib and the last rib, marbling, meat color, loin pH, and loin eye area. These measures will be compared between the rotationally grazed groups, the non- rotationally grazed groups, and industry norms for confinement raised pigs

    3. Average Daily Gain: All grain given to the pigs will be weighed and tracked. We will receive hanging weight information from the slaughterhouse. Using their ear tags, we will be able to cross reference each hanging weight with each ear tag number.

    4. Regrowth of Pasture and Assessment of Pasture Improvements: In each section, we will choose one half randomly to be disked and re-seeded after the pigs are removed. During the following spring of 2017, soils and pasture will be sampled monthly from April to July in all of the plots. (Total=7 paddocks x 2 samples x 3 replicates x 3 dates=126 samples)

    Statistical Design and Analysis: This design allows clear separation of the effects being studied for graphing and also statistical analysis, such as analysis of variance for randomized treatments or randomized blocks with split plots for effects of rotation, reseeding and their interactions (Anderson et al. 202, Gomez and Gomez 1984, Little and Hills 1978). This design allows clear separation of the effects being studied for graphing and also statistical analysis, such as analysis of variance for randomized treatments or randomized blocks with split plots for effects of rotation, reseeding and their interactions (Anderson et al. 202, Gomez and Gomez 1984, Little and Hills 1978). Such statistical analyses will be conducted under the guidance of our technical advisor.

    Timetable

    • Spring 2016: Set up pasture fences, housing, and drinkers
    • April 2016: Collect soil samples
    • Spring 2016: Acquire and process piglets, train to electric fence
    • Spring-Summer 2016: Pasture pigs
    • August 2016: Collect soil samples
    • August 2016: Present a farm and experiment tour at NOFA Summer Conference
    • Fall 2016: Slaughter hogs and assess carcass quality
    • October 2016: Collect soil samples
    • Fall 2016: Disk and Reseed pasture
    • February 2017: Present mid-project results at Pennsylvania Association for Sustainable Agriculture annual conference, “Farming for the Future”
    • February 2017: Visit Rodale Institute to learn about their pastured hog operations
    • April-July 2017: Collect soil samples on a monthly basis
    • August 2017: Present at the NOFA Summer Conference with all data, conclusions, and recommendations
    • Fall 2017: Write and submit an article to Cornell Small Farms Quarterly and OnPasture.com
    • Winter 2017: Present at Pennsylvania Association for Sustainable Agriculture annual conference, “Farming for the Future.”

    Outreach

    Outreach will be though many channels. We will post results in producer networks. Results and updates will also be posted on the Food, Farm, and Sustainability blog at Hampshire College. At our annual Fall Farm Festival, we will have a short presentation detailing our findings.

    Presentations:
    1. Field Trail Demonstration at NOFA Summer Conference, August 2016. We will offer a workshop session at the NOFA Summer Conference in Amherst, MA.
    2. Research presentation—mid-project results–at Pennsylvania Association for Sustainable Agriculture annual conference, “Farming for the Future”, in Winter 2017.
    3. Research presentation—final results—at NOFA Summer Conference, August 2017.
    4. Annual presentation at Hampshire Farm Fall Festival, 2016 + 2017

    Publications and print outreach:

    1. Hampshire College Food, Farm and Sustainability blog (http://sites.hampshire.edu/ffs/): monthly updates, written by student interns and Pete Solis

    2. Submit research report to Cornell Small Farms Quarterly which has a circulation of 27,000.
    3. Submit research article to “On Pasture”, an online publication highlighting the latest research and farmer/rancher experience and focused on turning ideas into farm and ranch ready practices.

    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.