Improving Feed Efficiency in Sheep Through Rumen Manipulation and Producer Adoption

Project Overview

Project Type: Graduate Student
Funds awarded in 2014: $25,000.00
Projected End Date: 12/31/2016
Grant Recipient: University of Wyoming
Region: Western
State: Wyoming
Graduate Student:
Principal Investigator:
Dr. Kristi Cammack
University of Wyoming

Annual Reports


  • Animals: sheep


  • Animal Production: inoculants, livestock breeding
  • Education and Training: extension, mentoring
  • Farm Business Management: budgets/cost and returns, value added

    Proposal abstract:

    Because feed costs for livestock are a substantial portion of production costs (> 65%), improving feed efficiency becomes more important as feed prices continue to rise. Improvements in feed efficiency can translate to reducing feed usage while maintaining animal performance. Mammals have sterile gastrointestinal (GI) tracts until birth that are continually colonized by microbial populations until weaning, when microbial populations become stabilized. The GI tract microbiota (i.e. microbial populations) differ in composition and abundance with body mass and feed efficiency. Furthermore, altering GI tract microbiota can improve overall GI health and enhance nutrient uptake efficiency in humans and rodents. Long-term application of rumen inoculation at birth has the potential to provide producers with a practical means of improving flock or herd feed efficiency, and ultimately, improving profit potential. This project's goal is to improve feed efficiency in sheep through 1) development of producer-friendly tools and strategies that improve feed efficiency, and 2) improved producer knowledge and use of feed efficiency measures and applications. To achieve our objectives, ewes of known high- or low-efficiency will serve as rumen fluid donors to twin lambs at birth; it has been shown that littermates and siblings exhibit limited microbiota variation. One twin will be selected for inoculation with high efficiency rumen fluid, and the other for inoculation with low efficiency rumen fluid. Inoculations will occur twice: first within eight hours of birth when rumen microbial populations are establishing, and second after two weeks when the rumen is becoming more fully functional. Twins will be tested for feed efficiency post-weaning to determine effects of rumen fluid inoculation. DNA extracted from donor and recipient rumen fluid will be sequenced to determine similarities between recipient and donor microbiota and to determine which microbial species influence feed efficiency. Results will be disseminated through presentations and publications to both scientific and producer audiences. Educational materials will be developed and distributed to enhance producer awareness and understanding of feed efficiency measures and tools. Economic analyses will be performed to determine economic implications of improving feed efficiency. Finally, producer adoption will be determined via feedback on materials and information assessed using surveys and interviews.

    Project objectives from proposal:

    The goal of this Western SARE Graduate Student project is to determine the potential to improve feed efficiency of sheep through manipulation of the rumen microbiota (i.e. rumen microbial species) at birth. We hypothesize that inoculation of lambs at birth with rumen microbiota from feed efficient adult sheep will alter lamb rumen microbiota and result in improved feed efficiency post-weaning. Human and laboratory animal research have demonstrated that microbiota can be positively altered through similar inoculation processes.

    The specific objectives of this project include:

    Objective 1. Determine if inoculation of lambs at birth with rumen microbiota from adult sheep identified as highly efficient and lowly efficient alters the rumen microbial profile.

    Objective 2. Determine if lambs inoculated with highly efficient and lowly efficient adult microbiota demonstrate increased and decreased feed efficiency, respectively.

    Objective 3. Enhance producer adoption and application of feed efficiency measures in sheep through development of educational materials and generation of a feed efficiency selection index.

    Objective 4. Determine the long-term economic implications of improving feed efficiency via rumen microbiota inoculation at birth.

    Our long-term goals are to improve feed efficiency in sheep and increase producer knowledge and awareness of the importance of feed efficiency in improving resource utilization and profitability. Improvements in feed efficiency can result in decreased feed usage, increased stocking ratios, and improved producer profitability through less input costs (e.g., decreased feed usage) or greater outputs (e.g., increased stocking ratios).

    Timeline for performance targets:

    Year 1: Collection of rumen fluid samples from known high- and low-feed efficiency donor adult ewes. Aliquots of rumen fluid will be used for inoculation and DNA sequencing.

    Year 1: Inoculation of twin lambs at birth; one twin inoculated with a high-efficiency donor sample and the other twin with a low-efficiency donor sample.

    Year 1: Lamb feed efficiency measurements post-weaning using a GrowSafe automated feed intake system.

    Year 1: Collection of rumen fluid samples from all twin lambs.

    Year 1: Development and dissemination of educational materials and producer surveys.

    Year 2: DNA sequencing of those samples along with donor aliquots to determine similarity of donor and recipient rumen microbial profiles.

    Year 2: Economic analysis and index development.

    Year 2: Dissemination of results.

    Year 2: Assessment of outreach efforts and producer adoption and application via producer surveys and interviews.

    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.