Silvopasture for Poultry Production with Outdoor Access: Impact on animal welfare, economic, and environmental parameters

Progress report for LS20-332

Project Type: Research and Education
Funds awarded in 2020: $275,079.00
Projected End Date: 03/31/2023
Grant Recipient: Virginia Tech
Region: Southern
State: Virginia
Principal Investigator:
Dr. Leonie Jacobs
Virginia Polytechnic Institute and State University (Virginia Tech)
Co-Investigators:
Dr. John Munsell
Virginia Tech - Department of Forest Resources and Environmental
Megan O'Rourke
Virgnia Tech
Gabriel Pent
Dept. of Crop and Soil Environmental Science, Virginia Tech
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Project Information

Abstract:

A silvopasture system involves intentionally integrating trees, shrubs and livestock on the same land. To date, these systems have largely been designed for ruminant livestock, such as cattle. However, novel silvopastures are being developed for poultry because these systems have potential to provide high quality habitat and feed sources that may improve bird health and welfare. The purpose of this project is to develop and assess sustainable poultry-based silvopastures. The research team combines expertise in broiler welfare (PI) and silvopasture production (co-PIs), plus large and small-scale poultry farmers as collaborators. Applying a systems-approach, we will assess animal welfare, economic, and environmental outcomes when integrating poultry production with novel silvopastures.

To meet certification requirements, organic chicken producers have to provide outdoor access. These ranges are grass pastures, yet chickens prefer overhead cover and shelter in their outdoor range. This habitat preference may be realized through the implementation of silvopastures. Using a novel silvopasture system could increase land-productivity through additional income from vegetation and reduced feed costs. Chickens may benefit from natural cover and increased range use, which is often limited. In turn it can lead to improved leg and feet health, diet diversity, and improved meat quality. Silvopastures would also improve animal comfort as the vegetation moderates understory microclimate. Environmental benefits could include improved soil quality, air quality, and biodiversity, which in turn can improve societal acceptance of poultry production. Although silvopasture systems offer many potential benefits, they have received little study in a poultry context, and even less extension and outreach effort. The project will contribute knowledge for family farm poultry systems, both on a large and small-scale, to provide information on how to improve profitability and stability.

 

Project Objectives:

This proposal is directed to poultry-centered silvopasture production systems. With this project, we aim to move existing organic poultry production systems toward more sustainable agriculture, in which animal welfare, economics, and the environment are balanced, and we want to strengthen awareness of existing silvopasture-based poultry production systems by collecting case studies that provide success stories and resources on how to overcome challenges. We will assess animal welfare, economic, and environmental parameters of combining silvopasture with poultry production by fulfilling three objectives:

Year 1:

  1. Experimental trial: Compare broiler chicken production with access to existing silvopastures to broiler production with access to grass pasture, at the VT Shenandoah Valley AREC, focusing on:
    • Animal welfare: behavior, fear, leg and feet health
    • Economics: animal yield and theoretical land yield
    • Environment: biodiversity and soil parameters

Year 1-3:

  1. Field trial:
    • (A) Compare broiler chicken production with access to a newly planted silvopasture on a large-scale commercial USDA Organic farm to grass pasture access on the same farm
    • (B) Compare broiler chicken production with access to established silvopastures on two small-scale commercial farms to grass pasture access on the same farms, focusing on:
      • Animal welfare: behavior, fear, leg and feet health
      • Economics: animal yield and theoretical land yield
      • Environment: biodiversity and soil parameters
  1. Increase adoption of poultry-based silvopasture practices by:
    • (A) Surveying silvopasture- and traditional-system poultry producers about their experiences, concerns and opportunities for applying these practices
    • (B) Creating and disseminating case studies from above-mentioned and other established silvopasture producers through extension
    • (C) Showcasing poultry silvopastures through research center and on-farm field days and web-based delivery tools
    • (D) Disseminating technical and budget information to producer and agency communities.

For objective 1 and 2, the same measures will be collected at four different sites: (1) the Virginia Tech Shenandoah Valley AREC, (2) a USDA Organic large-scale farm where we will plant a new silvopasture, (3 and 4) two small-scale broiler farms with established silvopastures. At all sites, we aim to compare measures in flocks with and without access to silvopastures (meaning grass range versus silvopasture range). Objective 3 is aimed at educating industry stakeholders and promoting the system’s benefits.

Cooperators

Click linked name(s) to expand
  • Wil Crombie - Producer
  • Adam Downing - Technical Advisor (Educator and Researcher)
  • Casondra Fields - Technical Advisor
  • Reginaldo (Regi) Haslett-Marroquin - Technical Advisor
  • Pam Miller - Technical Advisor - Producer
  • Brent Wills - Technical Advisor - Producer

Research

Materials and methods:

Our combined ‘research and extension approach’ includes a controlled experimental design (objective 1) comparing silvopasture access to grass pasture access for small flocks of broilers, executed at the Shenandoah Valley Agricultural Research and Extension Center (AREC). For objective 2, we will perform a field trial with a similar approach as objective 1, but applied at commercial farms. On each of the site (with possible exception of Wil Crombie’s farm), we will have a silvopasture-flock and a grass pasture-flock serving as a control to compare specific parameters related to welfare, economics and environment.

At the end of this study, an extension report will illustrate all these potential benefits and will contain photos and input from new and experienced silvopasture/broiler chicken producers than can serve as an educational document for industry stakeholders. Two field days will provide additional information on feasibility of the integrated system for interested parties and educate industry stakeholders on the system possibilities (objective 3).

Year 1 Objective 1 – Experimental trial: Compare broiler chicken production with access to existing silvopastures to broiler production with access to grass pasture, at the VT Shenandoah Valley AREC

 An experimental trial will be conducted at the Shenandoah Valley Agricultural Research and Extension Center (AREC) in Raphine, VA. A controlled experiment at the AREC will allow for repetitions of treatments and control over environmental and management factors, thus more statistical power to identify significant differences. We will grow 800 mixed-sex broiler chicken from a fast-growing commercial strain (e.g. Cobb or Ross, depending on availability) for six weeks until processing age (commonly 42 days old). These strains are often used for conventional, organic, and small-scale broiler chicken production. The trial will take place in the spring and summer to ensure appropriate weather conditions. Birds will be randomly allocated to one of 16 small-scale chicken coops with access to either established silvopasture (0.125 ha) containing a mixed hardwood stand or with access to open grassland pasture as a control. Forage species within both sites are similar, and include cool-season grasses and legumes. Birds will remain contained in their coop for 2-3 weeks depending on weather conditions to ensure appropriate climatic conditions for young birds. Birds will be fed a starter feed from week 1 to 2, grower from week 3 to 4, and finisher from week 5 to 6. Each coop will contain 50 birds. At day 42 of age, a sample of 10 birds per coop will be processed to determine yield.

We will place eight coops in an established silvopasture plot (total 2 ha). Fencing will be placed to separate the eight silvopasture treatment groups with equal silvopasture range sizes. In addition, eight coops with an equally sized grass range will be located near the silvopasture plot and serve will serve as the control plot (paddock).

Aerial view showing 8 silvopasture plots and 8 grass pasture plots
Experimental setup for objective 1 at the VT AREC. The orange rectangles indicate 8 silvopasture plots that will hold 50 broilers each. The maroon rectangles indicate the 8 grass plots that will hold 50 birds each.

Data will be collected, focusing on aspects of animal welfare, economics and environment.

Animal welfare. Range use may benefit leg health, footpad health and fearfulness. For all sixteen 50-bird flocks, range use will be assessed via two approaches; cameras (e.g. Bushnell Trophy Cam) and live observations. One photograph per hour will be taken within the chicken coop and used to calculate the percentage of birds outdoors each hour. Live observations will be conducted to count the number of birds in the outdoor range in week 4 and 5 for two days per week and three times a day (morning, midday, evening). Distance from the coop will be categorized (near the house, within 5 m; further from the house >5 m distance).

Assessment of how the management systems affect bird fearfulness will be determined with a Tonic Immobility test. The test consists of placing a chicken on its back in a U-shaped cradle and restraining it for 15 sec (Stadig et al. 2017). The chicken is then released and the time until righting (latency) is recorded, with longer durations of tonic immobility associated with greater fear. The test will be performed in week 5, after birds have had sufficient time to adopt to their respective environments, and 10 birds per coop will be assessed.

On the following day, leg condition will be assessed via a latency-to-lie test, in which birds are placed in a tote with a small amount of water. The time (latency) until the birds sit down will be recorded as an indicator of leg health or strength. In addition, footpad dermatitis and hock burns will be scored on a 0-4 categorical scale, with increasing scores indicative of worse lesions (Welfare Quality® Network 2009). Litter moisture, which will be assessed in the coop in the week prior to processing. Litter samples will be taken from multiple locations within each single coop, weighed, dried, and reweighed to assess moisture content (difference between weight 1 and 2 = moisture ‘weight’).

Economics. Economic productivity of the poultry system will be assessed by measuring animal growth (coop-level n = 50 per coop), feed conversion (coop-level, n = 8 per treatment) and whole-carcass yield (individual level n = 10 per coop). Feed intake will be recorded per group, starting from day 1 by weighing provided and left-over feed (difference = consumed feed). All birds will be weighed prior to processing on day 42 and carcass weights will be recorded thereafter for a sample of 10 birds per coop.

Environment. Temperature and humidity will be monitored in the range and within the coops using temperature-humidity sensors. We will assess soil quality on each plot twice to assess potential benefits from silvopasture/broiler production integration for the environment. Outdoor range soil quality will be assessed at three locations in each range (n = 16). To determine soil chemical properties, samples will be systematically collected at four distances from the coop (close, middle, end of range), resulting in 4 samples per flock per sampling time (baseline or post-experiment; total sample n(16*4*2)=128). At each location the surface litter will be removed and a sample collected with bucket soil augur. All samples will be homogenized separately by depth in a bucket onsite to obtain a single 50-g sample for each depth. Samples will be air dried and sieved with a 2-mm soil sieve. Soil sample analyses will be done to assess C and N, soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), C and N fractions, and phospholipid fatty acid content (PLFA). The latter is used as a biological indicator of overall soil quality (Quideau et al. 2016).

We propose to quantify insect diversity using a combination of direct observations, pitfall traps and sticky cards. Flowering plants will be observed directly to assess the quantity and diversity of pollinators, which will be grouped into the following categories: lepidoptera (butterflies), bumblebees, honeybees, other native bees, hoverflies, and wasps. Sticky cards will be used to assess flying insects, especially lady beetles. Pitfall traps will be used to assess ground beetles and orthoptera (especially crickets). We expect insect abundance and diversity to be greater in complex habitats with trees and native grasses than in conventional grass pastures.

JACOBS and GRAD STUDENT will be responsible for animal measures and soil collection with the technician, PENT will be responsible for silvopasture related measures, the environmental measures will be coordinated by O’ROURKE and soil samples will be analyzed through the South Dakota State University Soil Analysis Service Lab led by Dr. Sandeep Kumar (please see the letter of commitment for this contractual service here: Letter of Commitment SD STATE). 

Year 1-3 Objective 2A – Field trial: Compare broiler chicken production with access to a newly planted silvopasture on a large-scale commercial farm to grass pasture access on the same farm

Our cooperating large-scale VA-based poultry producer (SVO farmer Pam Miller) operates 3 commercial broiler chicken houses for approx. 90,000 birds. Each of the houses used in their system has pop holes along its length; these holes provide birds with access to grass pasture. On one of these three pastures we will establish a new silvopasture incorporating woody species and native grasses. Targeted woody species include Red Mulberry (Morus rubra), hazelnuts, pawpaw, and serviceberry. These species grow fairly rapidly and can provide shrubby cover and long-term feed resources. In addition to shrub cover, we will plant switchgrass (a native warm-season species) using sprigs (rather than seed) to generate rapid cover. Switchgrass is of interest given its potential to trap and reduce dust, to store carbon in deep root systems, and to serve as a source of bedding material or heating fuel for poultry operations.

The silvopasture system with trees, shrubs and grasses will be planted in rows parallel to the length of the house. The row-planting and space in between grasses, trees and shrubs (within rows) will allow for birds to move freely throughout the pasture. We will work with the landowners to design and install a mix of woody species and switchgrass based on their preference of vegetation and the physical layout of the space. The flocks with access to this newly established silvopasture plot will be compared to a control flock in one of the two adjacent houses.

For three production rounds spread over two years, we will collect data on animal welfare parameters (described for objective 1: fearfulness, leg health, footpad dermatitis and hock burns) in a sample of 80 birds per flock (two flocks per round) at week 5 of age. In addition, farmer and processing plant records will provide information on mortality, animal yield and carcass rejections. Litter moisture and soil quality data (6 samples per treatment (2), per round (3) = 72 soil samples total) will be assessed as described for objective 1.

 

Year 1-3 Objective 2B – Field trial: Compare broiler chicken production with access to established silvopastures on two small-scale commercial farms to grass pasture access on the same farms

 Similar to objective 2a, animal welfare, economic and environmental parameters will be assessed on two small-scale broiler operations (VA and MN). At these sites, producers already have integrated chicken production with silvopastures, or they have trees and shrubs as part of the outdoor range for broilers. The setup on the VA farm (small-scale producer Brent Wills) will be similar to the large-scale farm in that two flocks will be simultaneously grown, one with and one without access to shrubs and trees in their outdoor range (pasture versus silvopasture). All their birds have access to an outdoor range when temperatures allow. Broilers have full access to pasture and/or woods at all times once they come out of the brooder, usually at 2-3 weeks old, depending on time of year and weather. They grow a commercial hybrid breed (Freedom Rangers). All of their pastures border woods and fringe areas, so the birds have access to woods, trees and shrubby type vegetation, typically oak, hickory, maple, sourwood, pine thickets and the associated brambles and brushy vegetation. Their flock sizes depend on demand. Their pens allow for 80 birds per pen. They use Salatin-style pasture pens that offer 120 sf of “indoor” space per pen (10’x12’) as well as an A-frame pen with the same floor dimensions. For this study we will collect data during three rounds of production, with birds either with access to pasture (conventional outdoor range), or to vegetation (silvopasture).

On the MN farm (small-scale producer Wil Crombie), they grow birds according to the Regeneration Farms system/design for 5 years now. They have 40 acres and planted 20,000 hazelnut shrubs, around 5,000 elderberry bushes and a few thousand tree species, including oak, sugar maple, chestnut, basswood and Honey Locust. They currently have two active chicken barns. Their birds have outdoor access to grasses, Comfrey, Hazelnut and Sugar maple leaves and other naturally occurring plant species that are inside the paddocks. They also sprout grains within the paddocks. A single flock consists of 1,500 birds and is housed in a steel structure barn (18’x90′). The birds have outdoor access to circa 1.5 acres. At this point, we are not sure yet whether we can simultaneously assess birds with and without vegetation access as on the other farms and at the AREC.

For both farms, measurement include fearfulness, leg health, footpad dermatitis, hock burns on 80 birds per flock (n = 2 per farm, per round), assessed a week prior to processing. In addition, farmer and processing records will provide information on mortality and animal yield. Litter moisture and soil quality (6 samples per treatment (2), per round (3) = 72 soil samples total per farm) will be assessed as described for objective 1.

JACOBS and GRAD STUDENT will be responsible for animal measures, and collection of soil samples together with the technician, FIKE and MUNSELL will be responsible for silvopasture related measures. The environmental measures will be supervised by O’ROURKE and soil samples will be analyzed through the South Dakota State University Soil Analysis Service Lab lead by Dr. Sandeep Kumar.

 

Year 1-3 Objective 3: Increase adoption of poultry-based silvopasture practices

3A. Surveying silvopasture- and traditional-system poultry producers about their experiences, concerns and opportunities for applying these practices

Online search plus network search of southeastern US-based small and large scale silvopasture producers in combination with poultry. In addition, the director of the American Pastured Poultry Producers Association (APPPA) is willing to assist in the search for volunteers for the interviews among their members. We aim to perform at least six quantitative in-depth interviews in person, over the phone, or via email depending on geographical location and producer preference. Questions will relate to productivity, animal welfare, and environment. Additionally, we will ask about particular challenges and how they were overcome, including potential exposure to predators. We will collect photo material for the extension publication; a case-study report (b) (online and hard copies). Role of farmers: partake in interviews, allow or provide photos at/from farms. GRAD STUDENT will interview, perform farm visits, supervised by JACOBS.

3B. Creating and disseminating case studies from abovementioned and other established silvopasture producers through extension

Outcomes from interviews and farm visits will be structured and organized into an extension publication with photos and text. JACOBS will coordinate, GRAD STUDENT will write, collate, and disseminate (online and hard copies). MUNSELL, DOWNING, PENT and FIKE will advise on extension documents. Consultants and farmers will be involved with development and dissemination.

3C. Showcasing poultry silvopastures through research center and on-farm field days and web-based delivery tools

Two field days will be organized during which interested stakeholders are welcomed to visit at least one of the participating farms. The large-scale farmer already indicated willingness to assist with this field day and allow for visitors. The Shenandoah Valley AREC will be the location of a second field day for interested parties. These days will provide interested parties to see and experience a silvopasture approach and ask questions about this system. Some research outcomes will be presented to attendees for education purposes. Role of farmer: allow access to farm and talk about experiences. JACOBS will coordinate, FIKE and PENT will lead actual field days.

3D. Disseminating technical and budget information to producer and agency communities

Based on data collected for objective 1 and 2, we will be able to formulate some poultry-silvopasture system scenarios and calculate associated budgets for those scenarios. These will be disseminated as technical information with targeted audience being industry stakeholders. MUNSELL and DOWNING will coordinate silvopasture aspects of the technical and budget outcomes, JACOBS will coordinate animal-related aspects. Consultants and farmers will be involved with development and dissemination.

 

For objective 1 and 2, we will repeatedly assess the same measures at four different sites: (1) the Shenandoah Valley AREC, (2) a large-scale farm where we will plant a new silvopasture, (3) and (4) two small-scale broiler farms with established silvopastures. At all sites, we aim to compare measures in flocks with and without access to silvopastures (meaning grass range versus silvopasture range). This results in flocks as the experimental unit, with at (1) 16 flocks (8 with and 8 without silvopasture access), (2) 6 large-scale flocks (3 with and 3 without silvopasture access), (3) 6 small-scale flocks (3 with and 3 without silvopasture access), and (4) 3 small-scale flocks with silvopasture access. The commercial farms differ in farm size (small-scale versus large-scale), “age” of silvopasture system (newly established (year 0) versus well-established (~year 5)), and flock access to vegetation within a farm (flocks either have access to grass pasture or access to silvopasture). The first factor will illustrate the feasibility of integration vegetation production and broiler chicken production on a large scale compared to a smaller scale farm. The well-established silvopasture systems will be on small-scale farms, as the approach has not yet been used by large poultry producers. Our approach, in which we will plant a silvopasture system on a large farm, will provide insight regarding benefits associated with new silvopasture systems. The established systems (small-scale farms and the experimental trial from objective 1) will serve as “proof of concept” for a more commercial application, and will illustrate potential benefits on a longer term. Thus, the large-scale production system will illustrate the potential benefits on the short term, and the small-scale farms benefits on the long term.

Research results and discussion:

We have faced challenges due to the pandemic, that in part resulted in a delay in the research activities.

Objective 1 – Experimental trial: Compare broiler chicken production with access to existing silvopastures to broiler production with access to grass pasture, at the VT Shenandoah Valley AREC: We have prepared the experimental trial, with preparations including outlining plots, purchasing materials, building coops, placement of fences, and planting of additional vegetation in the silvopasture plots. We have collected 6 baseline soil samples per treatment group (silvopasture vs. grass pasture). Analysis of the baseline soil samples was performed in March 2021 in Dr. Sandeep Kumar’s lab. The broiler chicken trial is scheduled to start in April 2021. To ensure appropriate environmental conditions for the birds in the first three weeks of life, and to simulate large- and small scale production of broilers, we decided to house the birds at the poultry facility on campus (indoors) for three weeks prior to moving them in their coops and respective pastures. 

Objective 2A – Field trial: Compare broiler chicken production with access to a newly planted silvopasture on a large-scale commercial farm to grass pasture access on the same farm: Due to limitations related to the pandemic, we could not visit the cooperating farm early in the year. Further delays were caused by challenges related to identifying certified organic vegetation to plant in the pasture. Because of seasonal limitations, planting of vegetation at the commercial farm had to be postponed to the spring of 2021 (March). Baseline soil samples were collected from three pastures, and the analysis of the samples was performed in March 2021 in Dr. Sandeep Kumar’s lab.

Objective 2B – Field trial: Compare broiler chicken production with access to established silvopastures on two small-scale commercial farms to grass pasture access on the same farms: Due to limitations related to the pandemic, we could not visit the cooperating farms until late 2020 and early 2021. The first round of data collection is postponed until the summer of 2021. 

Objective 3A – Surveying silvopasture- and traditional-system poultry producers about their experiences, concerns and opportunities for applying these practices: We are in the process of getting the interview and survey methods approved by the Virginia Tech Institutional Review Board.

Objective 3B, C, D: Nothing to report

 

Participation Summary
4 Farmers participating in research

Education

Educational approach:

This project has a slow start due to the Covid-19 pandemic. We have recruited one PhD student for the project that will be in charge (under supervision) of the majority of data collection in the project. In addition, we recruited one undergraduate student for the experimental trial at the Shenandoah Valley Agricultural Research and Extension Center (Virginia Tech). 

Educational & Outreach Activities

1 Consultations
1 Curricula, factsheets or educational tools
1 Published press articles, newsletters
1 Webinars / talks / presentations

Participation Summary

4 Farmers
Education/outreach description:
  • Consultation 

We have been consulted by the CEO of a commercial broiler chicken integrator on recommendations for their new sustainable broiler chicken farm. More specifically, we provided recommendations for vegetation to plant in chicken pastures, including grasses, clover, trees and shrubs. Furthermore, we facilitated contact with extension agents and researchers on soil regeneration. 

  • Curricula, factsheets or educational tools (educational video)

We recorded video material during planting vegetation at the commercial poultry farm and at the VT AREC. This material will be used to develop an extension video on planting trees, and will feature a description of the project. The video is currently being edited.

  • Published press articles, newsletters (newsletter)

The PI is the co-founder of the Poultry Extension Collaborative (PEC). This collaborative consists of poultry extension faculty from four U.S. universities. The graduate student and the PI wrote a newsletter on incorporating silvopasture in poultry production. This newsletter is peer-reviewed by the other PEC members and distributed to newsletter subscribers (50), on the PEC website, and promoted through the PEC Facebook page. 

  • Presentation (stakeholder advisory council)

We have held our first stakeholder advisory council meeting during which the project was discussed in detail. 

Upcoming activities

  • Presentation: Stakeholder advisory council
  • Educational tool: Stakeholder interviews and subsequent reporting

Learning Outcomes

1 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
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.