Accelerating Advances in Animal Welfare - Request for Applications (RFA)

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Animal health and welfare are key to sustainable food security. Today there are approximately 19 billion chickens, 1.4 billion cattle and 1 billion sheep and pigs in farm production worldwide (Robinson, 2014). Globally, per capita meat and dairy consumption are expected to increase ~73% and ~58% by 2050 (FAO, 2011), respectively, as incomes rise in the developing world. These insights present both a challenge and an opportunity for improving animal lives in a rapidly growing world.

The intensification of livestock production in developed countries has improved efficiency and access to meat and dairy products, yet the treatment of farm-animals in these settings remains controversial. Challenges in intensive livestock production include the need to accommodate natural animal behaviors such as flight and rooting while reducing injuries and maladaptive behaviors. Surgical procedures may cause stress or pain depending on how they are performed. Innovative research is critical to developing new approaches in animal-welfare and ensuring their successful adoption. We are seeking partners to promote transformative animal welfare research with the potential to positively impact millions of animals as well as livestock-rearing best practices. FFAR will consider additional issues for future funding.

 

Key Dates

Application Opens
May 31, 2017 

Application Deadline
August 2, 2017 (4:59:59 PM Eastern Time)

Award Announcement
December 2017

Anticipated Funded Projects Start Date
January 2018

 

Contact

Please direct inquiries to: grants@foundationfar.org

 

Objective

The objective of this RFA is to stimulate and support innovative research in farm-animal welfare. Research is critical to progress in this field, as changes to animal production practices may impact animal physiology, may require large-scale alterations in animal housing and may have environmental and economic impacts that extend beyond the farm or production facility. FFAR expects the Animal Welfare program to support cross-disciplinary research in animal genetics, behavior, husbandry, physiology, biotechnology, nutrition and other scientific areas.

Current Research Areas

Cage-Free Poultry Welfare

The global demand for eggs and egg products is expected to increase significantly in the next several decades (USDA-ERS). In the United States, the move toward cage-free housing for egg-laying hens is progressing rapidly with the commitment by over 200 major restaurant and grocery chains, food manufacturers and producers, and hospitality and travel service industry groups to source eggs from cage-free poultry by 2025 or sooner. The USDA estimates that to meet these cage-free commitments, the egg industry will need to convert most current production systems to cage-free by 2025, at which time > 215 million layer hens will be housed in cage-free systems (USDA-AMS). However, there are biological and operational challenges associated with cage-free egg production. One common challenge is minimizing bone fractures, which can affect 50-75% of cage-free hens by the end of the laying lifespan (Lay, 2011; Nasr, 2012; Nicol, 2006; Petrik, 2015; Rodenburg, 2008; Wilkins, 2004), and fractures are reported to occur at higher rates in cage-free housing systems (Petrik, 2015; Sandilands, 2009). Bone fractures cause pain, decreased egg production, reduced growth efficiency and reduced carcass value (Nasr, 2012). Given the wide variety of evolving aviary designs and hen genetics, and the number of additional factors that can affect this issue problem, it is vital that researchers in the United States address this issue to support farmers as they transition to cage-free systems.

Impact and Feasibility of Addressing Keel Fractures

Keel fractures among poultry housed in aviary systems are considered a major welfare concern and negatively affect egg production. Bone strength in poultry is moderately to strongly heritable (40 %) (Bishop, 2000; Fleming, 2006), suggesting that selective breeding for bone strength could reduce the incidence of fractures. Research in this area may also impact osteoporosis, a closely related issue that affects > 80% of hens by the end of egg production and which contributes to bone breakage and 20-35% of mortalities during the egg-production cycle of caged hens (Webster, 2004; Whitehead, 2000). There are only a few major breeding companies that offer commercial poultry lines, which are typically selected for productivity, life expectancy and egg quality. Adoption of research findings by any of the major hatcheries would have significant impact on layer hen welfare. Dietary formulations or additives may reduce fractures by enhancing bone strength during egg production (Tarlton, 2013). Housing design and pullet rearing conditions may also significantly reduce keel fractures (Casey-Trott, 2017; Stratmann, 2015a,b; Wilkins, 2011).

 

Swine Welfare

Image of pigCurrently, the US produces 120-150 million swine per year and global demand for pork is projected to increase by 50% by 2050 (Alexandratos, 2012; Kruse, 2010). One of the most prominent welfare issues of pigs raised for commercial production is surgical castration of piglets, which is performed to prevent the development of malodor/taste known as boar taint in intact males and to reduce male aggressive behaviors. Males are castrated at an early age but analgesia is rarely used. Castrated piglets show an acute physiological stress response to castration including increased ACTH and cortisol levels, increased heart rate and behavioral indicators of pain that can last for four days following the procedure (Carroll, 2006; Hay, 2003; Hensch, 2011). Alternatives such as immuno-castration are not routinely used in the US due to logistical aspects of administration, cost and potential risks to humans. Developing alternatives to castration have the potential to greatly improve the welfare of 60-75 million piglets per year (USDA-NASS).

Impact and Feasibility of Developing Alternatives to Castration


Selection of animals with low boar taint may be possible due to the high heritability (25-87%) of this trait (Filardi, 2015; Rowe, 2014; Sellier, 2000), and some research has already been completed in this area. Interference with production of androstenone and skatole could be achieved by several methods. Unlike the dairy industry, sex selection of sperm in swine has been challenging and is not commonly performed.

Program Priorities

Applicants to the Farm-Animal Welfare Program must address one of the following program priorities, and that connection must be explicit in the application along with metrics to measure success of the research program:

1) Reducing keel bone fractures in cage-free housing systems.

FFAR is committed to supporting science-based approaches to this issue, including:

· Identification of quantitative trait loci and single nucleotide polymorphisms (SNP’s) that may assist primary breeders in selection for pro-welfare traits (e.g. bone strength) while maintaining egg quality
· Development of dietary formulations/additives for improved bone strength
· Research on microbiome/gut health and bone density
· Improved housing design (perch design, materials and placement, tier height, ramp angle, etc.)
· Improved rearing conditions (pullet housing design and management)

2) Development of alternatives to castration that provide for the piglet’s well-being and maintain pork quality

FFAR is committed to supporting science-based approaches to this issue, including:

· Selective breeding, or gene-editing, for production of animals with low physiological levels of androstenone and skatole
· Chemical interference with the production of androstenone and skatole hormones that cause boar taint
· Mechanical or genetic sex-selection of sperm (selection for female-only offspring)

Eligibility

The Foundation for Food and Agriculture Research welcomes applications from all domestic or international institutions of Higher Education, non-profit and for-profit organizations, government-affiliated researchers, and other organizations.

Only one application per organization/institution per program priority, for a total of two applications per institution.

This funding opportunity is for new activities only and should not be duplicative of other efforts. The proposed project can build upon existing research and activities, and applicants must clearly articulate what new elements this funding will support.

Award Information

Anticipated Project duration: Up to 60 months

Total Amount for this opportunity: At least $2 million

Amount per Award: Up to $500,000 total cost

Estimated Number of Awards: To be determined. Total number of projects to be funded under this opportunity depends on the quality and budgets of successful applications. FFAR reserves the right to negotiate all or none of the applications received for funding consideration under this opportunity.

Anticipated Award Date: December 2017

Application Information

Application Submission Guidelines

Applications must be submitted through FFAR’s online application receipt system (https://proposalcentral.altum.com/). Only applications submitted through this portal will be considered eligible for evaluation. If you are a new user, register for an account by clicking the orange “Create One Now” button. You will receive a confirmation email to sign-in to your account. Once you log in, search through the list of institutions to see if there is an institutional profile for your organization. If there is no institutional profile, ask your Grants & Contracts Department or Office of Sponsored Programs to register your organization. Once the organization’s profile is registered and saved, the PI can select their institution and complete his/her personal profile.  To access FFAR’s open funding opportunities, click the “Grant Opportunities” button on the top right corner of your screen, then on the top left corner of the screen, pull down the “Filter by Grant Maker” button and scroll down to select FFAR. Select the opportunity you would like to apply for by clicking the “Apply Now” button. The Principal Investigator may give access to others who will carry out part of, or participate in the proposed project, in Section Three of the online application. To invite individuals to participate in an application, the individual(s) must already have an account in the system. By applying, the applicant acknowledges and accepts the terms and conditions of the RFA.

 

Application Components

Download a PDF of this RFA

REQUIRED

1) Contact Information for:

·The applicant (applying organization)
· Principal Investigator
· Authorized Organization Representative (AOR)
· Grant/Contract Administrator (if different from AOR)

2) Project Title

3) Proposed Budget

4) Budget Justification (up to 1800 words)

5) Key Personnel involved in the project – name(s), affiliation, expertise, role on the project)

6) Project Personnel involved in other projects being submitted to FFAR)

7) Project Summary (up to 500 words)

8) Project Description (up to 5,000 words) including:

Introduction
· A description of how the project is relevant to the challenge of (A) addressing keel-bone fractures in cage-free layer hens or (B) developing alternatives to castration of swine.
· A summary of the knowledge that has laid the groundwork for this project, including any relevant preliminary work or data that has informed the development of the project. The summary should include references in the CBE citation style.
· A description of the potential impact the project may have in advancing farm-animal welfare.

Approach
· A statement of goals and supporting objectives for the proposed project.
· A detailed account of the procedures or methodology you will use to achieve the goals and supporting objectives. The account must have enough resolution for a panel of experts to judge the merit of the project. All application information is treated as confidential. The account should include:
· Proposed project activities described sequentially.
· Techniques to be used, including their feasibility and rationale.
· If applicable, stakeholder involvement in the development of the approach.
· A description of anticipated risks and how you will mitigate them.
· How data will be analyzed or interpreted.
· Expected results and information, and how it can be used by the food and agriculture community to spur further research or directly animal health and welfare.
· Plan to communicate results or amplify outcomes to stakeholder audiences. For projects focusing on the Education and Outreach focus area, this should describe how you will share lessons learned beyond your project.

Timeline
· A project timetable in tabular form. Minimum resolution should be annual goals and objectives, to be used to evaluate annual progress reports. If applicable, include periods beyond the grant funding to demonstrate impact and longevity of the work.

9) Data Management Plan (up to 1,500 words)

10) References Cited (upload; no word limit)

· If there are no references cited, a statement to that effect should be included in this section of the application. Each reference must include the names of all authors (in the same sequence in which they appear in the publication), the article and journal title, book title, volume number, page numbers, and year of publication. If the document is available electronically, the website address also should be identified. Applicants must be especially careful to follow accepted scholarly practices in providing citations for source materials relied upon when preparing any section of the application. While there is no established page limitation for the references, this section must include bibliographic citations only and must not be used to provide parenthetical information outside of the Project Description.

11) Graphics, Figures, Equations, and Tables (up to 5 single-side pages). The textbox for the Project Description does not support equations, tables, graphics, and figures. Applicants may upload a PDF document with graphics, figures, tables, or a list of equations to support the research program plan. This section should not be used to circumvent the page limit for the Project Description Section.

12) Organizational Assurances

· Research involving human subjects
· Research involving vertebrate animals
· Research involving Recombinant DNA
· Research Involving National Security implications
· Research involving hazardous materials
· Research involving human fetal tissue
· Research involving NEPA review

13) Facilities, Equipment, and Other Resources (up to 500 words)

·This section of the proposal is used to assess the adequacy of the resources available to perform the proposed project. Include an aggregated description of the internal and external resources (both physical and personnel) that the organization and its collaborators will provide to the project, should it be funded. The description should be narrative in nature and must not include any quantifiable financial information. Reviewers will evaluate the information during the proposal review process. FFAR expects that the resources identified in the Facilities, Equipment, and Other Resources section will be provided, or made available, should the proposal be funded.

14) Budget Form.

· Please use template provided.

15) Current and Pending Support Form.

· Complete for everyone listed as PI or Key personnel on the project. Please use template provided.

16) Biosketches for the PI and other key personnel.

· Please use the template provided. Applicants must combine all biosketches and/or curriculum vitae into a single PDF document before uploading as an attachment.

17) Letters of Support

· Applicants may provide letters of institutional, collaborator, or stakeholder support for the proposed project. Please combine all letters of support into a single PDF document before uploading as an attachment.

OPTIONAL FORMS: MATCHING FUNDS

FFAR has currently obtained matching funds from Open Philanthropy to fund this opportunity. Therefore, applicants are not required to provide a match. However, if additional funds are available to support the proposed project, please indicate the level, source (no federal funds), and type (cash or in-kind) of these additional funds. The project description, budget, and budget justification should reflect the total funds requested from FFAR, and any additional voluntary funds available for the project. The availability or non-availability of voluntary additional funds will not favorably or unfavorably affect the evaluation of the proposal.

· Matching Funder Form. Please use template provided.

· Certification of Matching Funds. Please use template provided.

Review Process

All submitted applications will go through an internal review process to ensure that the proposed project is relevant to the RFA and suitable to FFAR’s mission. Submitted applications will undergo further review using a two-stage peer review process: (1) External Peer Review, and (2) FFAR Advisory Council review. In the first stage, applications will be peer-reviewed by independent, external scientific experts using the review criteria posted below. In the second stage, applications judged to be most meritorious by the peer reviewers will be evaluated and recommended for funding by the FFAR Advisory Council based on comparisons with applications from the same cycle and FFAR’s program priorities. All reviewers are required to read and acknowledge acceptance of FFAR’s Conflict of Interest Policy and Non-Disclosure Agreement. We make reasonable efforts to ensure that applications are not assigned to reviewers with a real or apparent conflict with the applicant or project personnel. Reviewers with conflict of interests are recused from evaluating or participating in discussions of applications with which they have a conflict. Each stage of the review is conducted confidentially, and as such, FFAR is responsible for protecting the confidentiality of the contents of the applications it receives.

Applications recommended for funding by the Advisory Council will go to the Scientific Program Director and FFAR’s Executive Director to consider program priorities set by the Board of Directors, portfolio balance across programs, and available funding.

Applications are evaluated based on scored primary review criteria and unscored secondary review criteria. The bullets under each criterion may serve as a guideline to applicants when writing their applications, and as a guideline to reviewers on what to consider when judging applications. The bullets are illustrative and not intended to be comprehensive. Reviewers will evaluate and score each primary criterion and subsequently assign a global score that reflects an overall assessment of the application. The overall assessment will not be an average score of the individual criterions; rather, it will reflect the reviewers’ overall impression of the application. Evaluation of the scientific merit of each application is within the sole discretion of the peer reviewers and they may raise additional factors to consider that are not covered in the bullets for each criterion. Applications submitted under this RFA will be evaluated by the criteria listed below.

Primary Review Criteria

Reviewers use the primary review criteria to evaluate the scientific merit and potential impact of the proposed project. Concerns with any of these criteria potentially indicate a major flaw in the significance and/or design of the proposed work.

Scientific innovation (25%)

Has the applicant demonstrated that this research has not been done elsewhere, or that this research accelerates a current research challenge or addresses the agricultural challenge in a new or innovative manner?
Does the project describe innovative scientific methods and approaches?
What research gaps will be addressed by this project?

Potential impact and expected outcomes (25%)

What are the expected outcomes of this project? How well did the applicant describe those outcomes?
Does the applicant describe a viable plan for implementing results that involves farmers, producers or companies?
Does the project have the potential to impact a large number of poultry or livestock?

Adequacy of the research description and project feasibility (20%)

Are the aims/objectives of the proposed project clearly presented?
What methods will be used to achieve those aims and objectives and do they appear feasible?
Are the plans outlined by the applicant to monitor and evaluate the project clearly outlined?
What risks could inhibit the success of the project and how will well did the applicant describe their plan to avoid/overcome them?
Is the budget commensurate with the proposed work?
What are the milestones associated with the project and are they outlined?
Does the timeline provided by the applicant seem feasible for accomplishing the work outlined?

Project Personnel and research environment (10%)

Who will conduct the work and are their qualifications sufficient to carry out the proposed research?
Are there partnerships that strengthen the capacity to carry out the goals or implementation of the project?
Is the research environment (facilities, equipment and institutional/corporate support) appropriate to conduct the research?

Dissemination and implementation of results (20%)

How will the grantee manage and disseminate data generated by this project?
In the case of projects producing proprietary information/technology, how effectively did the applicant describe the funding of the production of proprietary information and/or judicious use of public funding?
How adequate is the plan to disseminate results to other researchers and to producers?
Did the applicant describe, where applicable, how they would implement and incorporate results or products into existing food production systems?

Secondary Review Criteria

Secondary review criteria contribute to the global score assigned to the application. Concerns with these criteria potentially question the feasibility of the proposed research. Examples of secondary review criteria are, Budget, Duration of the project, Protections for Human and Animal Subjects, and Previous Project Performance. Reviewers are not asked to score secondary review criteria, though they may consider these criteria when determining the overall merit of the proposal.

Award Notice

Selection Notice

Following application review, the principal investigator and the authorized organization representative listed on the project will be officially notified by email whether (1) the application has been selected for funding pending grant agreement negotiations, or (2) the application has not been selected funding. If an application is selected for funding, the Foundation for Food and Agriculture Research reserves the right to request additional or clarifying information for any reason deemed necessary, including, but not limited to, matching funds, or other budget information. Potential grantees are free to accept or reject the Grant Agreement as offered.

Award Notice

FFAR notifies applicants of whether they are selected for funding through email. The notice does not constitute an award or obligate funding from FFAR until there is a fully executed grant agreement.

Grant Period(s)

Upon receipt of the Grant Agreement, the potential grantee should note the Effective Date and the Expiration Date. Grantees may only use FFAR funds on project expenditures on or after the Effective Date of the Grant. Charging expenditures to the grant prior to the effective date is strictly prohibited. Likewise, grantees may not use FFAR funds after the Expiration Date except to satisfy obligations to pay allowable project costs committed on or before that date. The expiration date is the last day of a month.

Once the Grant Agreement is fully executed, the Effective Date cannot be changed. The Expiration Date may be changed with a written approval of a no-cost extension request by FFAR. If a no-cost-extension request is approved, FFAR will issue an amendment to the Grant Agreement.

If the grantee requires additional time beyond the Grant Period and the established Expiration Date to assure adequate completion of the original scope of work within the funds already made available, the grantee may request a one-time no-cost extension of up to 6 months. The request must be submitted to FFAR at least thirty (30) days prior to the Expiration Date of the grant. The request must explain the need for the extension and include an estimate of the unobligated funds remaining and a plan for their use. This one-time extension will not be approved merely for using the unexpended funds.

Post-Award Management

Reporting Requirements

After a grant is conferred, the grantee shall provide an annual financial report to FFAR showing grant expenditures to date. The grantee shall also provide an annual progress report to FFAR showing activities being carried out under the grant, including but not limited to project accomplishments to date and grant expenditures. Within 30 days of completion of all grant activities, the grantee shall provide a final progress report. The final progress report should address the original objectives of the project as identified in the application, describe any changes in objectives, describe the final project accomplishments, and include a final project accounting of all grant funds.

If awarded, grantees will be expected to:

·Agree to publish a pre-analysis plan which includes the abstract, hypothesis, project personnel (PI and key personnel), project duration, expected outcomes and award amount in a publicly accessible location.
·During the study, notify FFAR of significant deviations from the pre-analysis plan.
·Make the full data-set, the code used to analyze it, and any other necessary materials publicly available within six months of publishing the study.
·Post a pre-print or working paper version within 8-12 weeks of submitting the study for publication, if journal allows pre-prints to be posted online.

 

Scientific Integrity

FFAR’s ability to pursue its mission to build unique partnerships to support innovative science addressing today’s food and agriculture challenges depends on the integrity of the science on which it relies. A fundamental purpose of FFAR is to facilitate the advancement of knowledge and the application of the science to address challenges relevant to the FFAR’s mission. All FFAR grants must be conducted with the highest standards of scientific integrity.

 

Grant Terms and Conditions

The Foundation for Food and Agriculture Research expects applicants to have reviewed the Grant Agreement prior to applying to ensure that the applicants are aware of the applicable terms under which the grant is offered. FFAR will only entertain potential modifications to the Grant Agreement under the most exceptional circumstances. Successful applicants are strongly encouraged to sign the Grant Agreement as presented.

Contact Information

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Scientific and Grants Questions Contact

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References

Carroll et al. (2006) Hormonal profiles, behavioral responses, and short-term growth performance after castration of pigs at three, six, or twelve days of age. J Anim Sci, 84:1271-1278

Casey-Trott, et al. (2017) Rearing system affects prevalence of keel-bone damage in laying hens: a longitudinal study of four consecutive flocks. Poult Sci, pex026. doi: 10.3382/ps/pex026

FAO. 2011. World Livestock 2011 – Livestock in food security. Rome, FA. https://doi.org/10.1371/journal.pone.0096084

Filardi de Campos C, Lopes MS, Fonseca e Silva F, Veroneze R, Knol EF, Lopes PS, Guimarães SEF. 2015. Genomic selection for boar taint compounds and carcass traits in a commercial pig population. Livestock Science, 174:10–17

Fleming RH, McCormack HA, McTeir L, and Whitehead CC. 2006. Relationships between genetic, environmental and nutritional factors influencing osteoporosis in laying hens. British Poultry Science, 47(6):742- 55. 258

Hay et al. (2003) Assessment of pain induced by castration in piglets: behavioral and physiological responses over the subsequent 5 days. Appl Anim Behav Sci, 3:201-218

Hensch et al. (2011) Using Serum Cortisol to Distinguish Between Acute Stress and Pain Response Following Castration in Piglets. Animal Industry Report: AS 657, ASL R2638.

Kruse J. Estimating demand for agricultural commodities to 2050. 2010. Global Harvest Initiative

Lay Jr. DC, Fulton RM, Hester PY, Karcher DM , Kjaer JB, Mench JA, Mullens BA, Newberry RC, Nicol CJ, O’Sullivan NP, Porter RE. 2011. Emerging Issues: Social Sustainability of Egg Production Symposium, Hen welfare in different housing systems. Poultry Science,. doi:10.3382/ps.2010-00962

Nasr et al. (2012) The effect of keel fractures on egg production, feed and water consumption in individual laying hens. Animal Welfare, 21: 127-135 ISSN 0962-7286

Nicol CJ, Brown SN, Glen E, Pope SJ, Short FJ, Warriss PD, Zimmerman PH, Wilkins LJ. 2006. Effects of stocking density, flock size and management on the welfare of laying hens in single-tier aviaries. British Poultry Science, 47(2):135-46.

Petrik et al. (2015) On-Farm Comparison of Keel Fracture Prevalence and Other Welfare Indicators in Conventional Cage and Floor-Housed Laying Hens in Ontario, Canada. Poult Sci, 94 (4): 579-585

Robinson TP, Wint GRW, Conchedda G, Van Boeckel TP, Ercoli V, Palamara E, Cinardi G, D'Aietti L, Hay SI, Gilbert M. 2014. Mapping the global distribution of livestock. PLoS One, http://dx.doi.org/10.1371/journal.pone.0096084

Rodenburg et al. (2008) Welfare assessment of laying hens in furnished cages and non-cage systems: an on-farm comparison. Animal Welfare, 17(4): 363-373

Rowe SJ, Karacaören B, de Koning DJ, Lukic B, Hastings-Clark N, Velander I, Haley CS, Archibald AL. 2014. Analysis of the genetics of boar taint reveals both single SNPs and regional effects. BMC Genomics, 15:424

Sandilands et al. (2009) Providing laying hens with perches: fulfilling behavioural needs but causing injury? British Poultry Science, 50: 395-406.

Sellier, P. Le Roy, M. Fouilloux, J. Gruand, M. Bonneau. 2000. Responses to restricted index selection and genetic parameters for fat androstenonelevel and sexual maturity status of young boars. Livest. Prod. Sci., 63, pp. 265–274

Stratmann et al. (2015) Soft Perches in an Aviary System Reduce Incidence of Keel Bone Damage in Laying Hens. PLosOne, https://doi.org/10.1371/journal.pone.0122568

Stratmann A., Fröhlich E. K. F., Gebhardt-Henrich S. G., Harlander-Matauschek A., Würbel H., Toscano M. J. 2015. Modification of aviary design reduces incidence of falls, collisions and keel bone damage in laying hens. Appl. Anim. Behav. Sci. 165 (2015): 112-123.

Sumner et al. (2011) Economic and market issues on the sustainability of egg production in the United States: Analysis of alternative production systems. Poult Sci, 90 (1): 241-250. doi: 10.3382/ps.2010-00822

Tarlton J. F., Wilkins L. J., Toscano M. J., Avery N. C., Knott L. 2013. Reduced bone breakage and increased bone strength in free range laying hens fed omega-3 polyunsaturated fatty acid supplemented diets. Bone 52(2):578-86

USDA-AMS Egg Markets Overview: https://www.ams.usda.gov/sites/default/files/media/Egg%20Markets%20Overview.pdf

USDA-ERS data: https://www.nass.usda.gov/Charts_and_Maps/Poultry/

USDA-NASS data: https://www.nass.usda.gov/Charts_and_Maps/Hogs_and_Pigs/

Wilkins et al. (2011) Influence of housing system and design on bone strength and keel bone fractures in laying hens. Vet Rec, 169: 414. pmid:21862469