Progress report for OW23-380
Project Information
The University of Wyoming (UW) is collaborating with Katahdin sheep producers in the intermountain west region and Dr. Tom Murphy at the U.S. Department of Agriculture U.S. Meat Animal Research Center (US-MARC) to evaluate optimal feeding and management strategies for harvest lambs from producers and collaborators. This collaborative research and education project utilizes producer lambs in three diet and management groups to better understand the optimal harvest animal guidelines for Katahdin producers utilizing dam, sire and lamb information, live animal performance and ultrasound data, carcass characteristics and sensory performance information to develop best management practices for Katahdin producers to implement. Since limited information is currently available for producers to reference, this project provides live animal and carcass data back to producers to use to enhance their animal and product marketing programs in addition to developing prediction and economic tools to better assist producers with estimating optimal lamb harvest endpoints more precisely based on sire, dam and lamb performance records. Current Katahdin lamb producers are collaborating with researchers at UW and US-MARC to receive performance records for producer owned lambs participating in this work along with engaging in field-demonstrations and workshops to demonstrate tools and materials developed for Katahdin lamb producers to implement into their operations. Materials, workshops, demonstrations are being developed and planned for evaluation during planned educational events and at 12-month follow-up surveys to assess implementation of targeted feeding and management strategies.
Research Objectives
The objectives of this research and education project are to: 1) evaluate the impact of type and duration of diet on live animal growth performance, carcass characteristics and sensory outcomes among Katahdin lambs from participating producers; 2) utilize lamb performance data along with dam and sire information to develop prediction equations and evaluation tools to determine optimal harvest weights for Katahdin producers; 3) evaluate impact of forage based diet resources, and 4) utilize research results from this project with producer management and perception survey findings in hosted field day and/or additional workshops to more effectively coordinate adoption of precision management tools and economic calculators for Katahdin producers.
Educational Objectives
The overall educational goal of this project are to: 1) provide producers with complete performance data of their lambs in order for each to implement new management strategies best tailored for their operation; 2) evaluate current management and marketing strategies used by producers in the intermountain-west region; and 3) provide effective education utilizing interactive management tools developed through this project 4) pre-and-post assessment of knowledge gained including gauging use and perception of management tools developed.
This project started in September 2023. The first producer survey (baseline or pre-project survey) was developed and distributed between January and March 2024 to capture producer information to support the overall educational objective, which is to provide targeted programming during the extension field day held in year 2 of the project. Approaches and activities to support Research Objectives 1, 2 and 3 have been planned and developed during Year 1 of the project with producers directing planning events. Sensory analysis, chemical analysis of loin muscle and image analysis is planned during Year 2 to support Research Objectives 1 and 2. Additional activities planned in Year 2 are planned to address Research Objective 4 and Education Objectives 1, 2 and 3. Publication of results in Year 3 will be the ultimate activity as a result of Research Objectives 1, 2 and 3 during Years 1 and 2 of the project. Final Implementation and Survey (post-project survey) activities will occur in Year 3 to support Education Objectives 1, 2 and 3. Below is an overview of specific activities proposed during the 3 year research and education project. In addition to specific activities highlighted in the timeline visuals below, additional educational materials such as developing a national recorded webinar and adding project resources to the University of Wyoming Animal Science Extension Webpage and Youtube sites will occur in Years 2 and 3.
Cooperators
- - Producer
- - Producer
- - Technical Advisor (Researcher)
- - Technical Advisor
- - Producer
- (Researcher)
- (Researcher)
Research
Research Objectives
The objectives of this research and education project are to: 1) evaluate the impact of type and duration of diet on live animal growth performance, carcass characteristics and sensory outcomes among Katahdin lambs from participating producers; 2) utilize lamb performance data along with dam and sire information to develop prediction equations and evaluation tools to determine optimal harvest weights for Katahdin producers; 3) evaluate impact of forage based diet resources, and 4) utilize research results from this project with producer management and perception survey findings in hosted field day and/or additional workshops to more effectively coordinate adoption of precision management tools and economic calculators for Katahdin producers.
Objectives 1-3:
Animal Enrollment
An Institutional Animal Care and Use Committee (IACUC) protocol (# 20221102CG00576) was updated and approved in November 2023 prior to research activity commencing. The research team is collecting ewe and ram weights via a portable scale at producer and collaborator locations if weights have not been previously recorded at each location. Historical records for each lamb consisting of date of birth, birth type (single, twin, triplet), vaccination status, weaning weight, calculated weaning age and records of each dam consisting of age, number of lambs weaned, number of successful parities reared, mature dam and sire weight and frame size, and any other relevant information available is being recorded. Lambs from producers and collaborators are being enrolled and will be transported to the University of Wyoming-Laramie Research and Extension Center (UW-LREC) located in Laramie, Wyoming, for the duration of the research trial during Summer 2024. At the UW-LREC, lambs will be weighed, ultrasound 12th rib fat thickness and loineye depth measured, and will receive an EID (electronic identification tag) to maintain animal identity throughout the experiment to demonstrate traceability. All lambs will be fed grass hay in confinement using the Vytelle feed efficiency system (formerly GrowSafe) to characterize feed efficiency of each individual lamb before assigning to a nutritional treatment.
Treatment Overview
Lambs (n=50 per treatment) will be assigned to one of three dietary management treatments consisting of the following: grazing only (GO) high meadow grass, grain feeding (GR), or extended grazing followed by grain feeding (BG). The same live weight will be targeted for each group of lambs through continuous weekly and biweekly monitoring to pinpoint changes in yield via ultrasound. A tentative timeline of treatments is provided below in this proposal. Weekly ultrasound and feed efficiency metrics will be used to assess optimal harvest weight.
Management of Lambs During Grazing
Lambs backgrounded on grazing (GO) or grazing followed by grain-feeding (BG) will be allowed to graze a pasture consisting of high meadow grasses. If available grass becomes impacted by weather, grass-hay produced from the same grasses will be supplemented to either treatment. Lambs will be weighed and ultrasounded monthly during the grazing portion of each treatment. Ward Laboratories will be used as a contracted service to analyze forage and feed samples during the research trial and in subsequent years for producer adoption of management strategies.
Management of Lambs During Grain-Feeding
Lambs assigned to grain-feeding (GR) or backgrounded followed by grain-feeding (BG) will be transitioned from a predominately grass-hay to full feed of a high energy grain-based through a series of step-up transitions by 0.5% of mean live body weight until lambs have successfully been stepped up to full access of the high energy diet. The Vytelle System will be used to measure feed intake of each individual lamb to calculate feed efficiency and feeding behavior information. Live body weights will be recorded each week and 12th rib fat thickness and loineye depth will be recorded bi-weekly.
Animal Harvest and Postmortem Data Collection
Once each nutrition management treatment has concluded, a two-day live body weight, final ultrasound measurements, frame size and animal images will be recorded. Final live animal muscle scores will be recorded by two trained evaluators. Animal harvest will occur at a commercial lamb harvest facility under the supervision of a food animal. Animal identification will be maintained throughout the processing facility (live animal to carcass). Carcasses will chill for approximately 24 hours before comprehensive carcass data and yield information is collected. A loin sample will be collected from each carcass, transported to the University of Wyoming Meat Laboratory under refrigerated conditions, aged in vacuum packaging for 7 days, fabricated into 2.54 cm thick loin chops that will be used for sensory and tenderness analysis, pH measurement, proximate (protein, fat, moisture and ash) analysis and fatty acid analysis, and loin chops vacuum packaged and frozen to stop the aging process until analysis occurs.
Chemical Analysis: pH Determination, Proximate and Fatty Acid Analysis
A portion of one loin chop will be homogenized in distilled, deionized water for approximately 1 minute before using an electrode and calibrated tabletop pH meter to record pH three times per sample. Fat and connective tissue from 2-3 loin chops will be removed and the muscle will be frozen in liquid nitrogen and blended into a fine powder for proximate and fatty acid analysis. A chloroform:methanol solution will be used to begin fat extraction from homogenized samples. A series of agitating the sample solution, filtering and adding 0.9% NaCl will be used to extract fat into a low solution phase and drying and weighing will be used to calculate crude fat. Crude protein will be measured using a nitrogen analyzer that combusts a homogenized muscle sample and detects the amount of nitrogen that will be used to calculate protein content. A forced air-drying oven at 100°C will be used to dry homogenized muscle and the difference in pre-drying and post-drying weights will be used to calculate moisture content. and samples reweighed to calculate percent moisture. Similarly, a Thermolyne box furnace at 550°C will be used to heat homogenized muscle and the difference in pre-heating and post-heating weights will be used to calculate ash content. An internal standard will be added to freeze dried homogenized muscle along with chemical reagents (4 mL of 0.2 M Methanolic Potassium Hydroxide, 1 mL of saturated Sodium Chloride and 2 mL of high grade hexane) in a series of incubation, mixing and centrifuging steps to prepare free fatty acids from the muscle samples before separating and detecting fatty acids with a gas chromatograph equipped with a flame ionization detector. Agilent ChemStation software will be used to quantify and identify individual fatty acids. Replicates of each sample will be measured for all proximate and fatty acid anslyses and averaged to account for technical variability.
Cooking and Shear Force
Chops designated for shear force that were previously frozen will be randomly assigned to a cooking day. Steaks will be tempered under refrigeration at 0 to 4°C for 12 h prior to cooking. Tenderness evaluation will be conducted on steaks randomly assigned to sous vide immersion cooking for 3 or 24 hrs. at 60°C, 71°C or 77°C. Thawed steaks will be weighed, weighed after blotting excess moisture and added to a sous vide cook-in bag. Steaks will be cooked in three immersion water temperatures in a water bath with a immersion circulator to achieve 3 degrees of doneness (rare, medium and well) for 2 time durations (3 h or 24 h; time durations selected to mimic realistic cooking approaches that consumers could utilize). Slice Shear Force (SSF) and Warner-Bratzler Shear Force (WBSF) measurements will be obtained from designated shear force chops using procedures described by Lorenzen et al. (2010). For SSF, a 1-cm-thick, 5-cm-long slice will be removed from the steak parallel to the muscle fibers and sheared perpendicular to the muscle fibers, using a shear force testing machine (Tallgrass Solutions, Inc., Manhattan, KS) within 10 min of recording peak internal temperature using a slice shear force shear head. The remaining portion of each chop will be allowed to equilibrate to room temperature (approximately 21°C) and a maximum number of cores (1.2 cm in diam.) will be removed from each steak parallel to the muscle fibers for WBSF. Each core will be sheared once, perpendicular to the muscle fibers, using a shear force testing machine (Tallgrass Solutions, Inc., Manhattan, KS) fitted with a Warner-Bratzler shear head. Maximum peak shear force of each core will be recorded, and the resulting values were averaged to obtain a single shear force value for each steak.
Trained Sensory Analysis
A trained descriptive attribute panel will quantify descriptive sensory attributes of each sample using 15-cm unstructured line scales anchored at both ends with descriptive terms. Before sample evaluation, modified reference samples will be used to train panelists for at least 6 sessions. Sensory analysis will focus on rating tenderness, juiciness, lamb flavor identity (characterizing lamb flavor and aroma), mutton-like flavor (offensive flavor and aroma), fat-like, livery/organy (flavor and aroma associated with cooked liver), green/hay-like (flavor and aroma of meat produced by grass-finished animals), and the basic tastes of salty, sweet, sour, bitter, and umami.
Statistical Modeling
Data obtained from this professional-producer project are being used to predict optimal live animal body weight targets for each participating producer, provide each collaborator a summary of lamb growth performance, live animal composition, feed efficiency, carcass performance and sensory data. All data are being used to develop better prediction equations for optimal finishing body weight by trial (all lambs), producer and by sire. Based on these data, a series of scoring materials and online calculators will be developed for producers. All objective data will be used to develop statistical models to compare diet treatment and to assess prediction models for optimal live weight targets. The ultimate goal of this research is to use this information to accomplish objective 4 to educate, train and evaluate the adoption of this information and developed resources among producers in a field day and/or workshops.
The research for this project is still ongoing. Majority of data for this project are expected to be collected by fall 2024 - early spring 2025. Results from research objectives will be provided in the project update report for year 2.
Research Outcomes
This grant entitled 'Enhancing producer decision making: Lamb feeding strategies and meat quality assessment in the Katahdin sheep breed' was approved and started on September 5, 2023. During the first 7 months of the project, a new M.S. graduate student started her program with a focus on this work. Participating producers have spring lambing dates, so the major research activity for this project has been planned with these producers and the lamb enrollment/feeding trial research will begin in July 2024 under approved IACUC protocol # 20221102CG00576. The research objectives are planned and in progress for Summer 2024 in order to utilize Katahdin lambs at a controlled starting body weight. Through Education Objective 2 that included a comprehensive survey distributed to approximately 400 producers to date, numerous producers have committed interest in enrolling their lambs into the research trial commencing in July 2024.
Education and Outreach
Participation Summary:
Materials and Methods
The overall educational goal of this project are to: 1) provide producers with complete performance data of their lambs in order for each to implement new management strategies best tailored for their operation; 2) evaluate current management and marketing strategies used by producers in the intermountain-west region; and 3) provide effective education utilizing interactive management tools developed through this project 4) pre-and-post assessment of knowledge gained including gauging use and perception of management tools developed.
The overall purpose of this project is to provide Katahdin producers with research results and developed materials to assist their management plans to produce lambs that optimize economic, performance, sensory and marketing objectives. This plan is being accomplished through multiple avenues. Planned educational activities and products are included below.
Engagement with regional and national producer groups (e.g., Rocky Mountain Katahdin Association and Katahdin Hair Sheep International) to maximize survey participation of Katahdin stakeholders. A physical copy of a producer survey was distributed to approximately 400 producers. An electronic survey version was developed and is currently being distributed to producers to expand response rate. This survey was developed to assess current production practices (i.e., diets utilized, live weight of lambs at the time of marketing, dam/sire body weights, and constraints to production and marketing strategies at the beginning of year 1.
For participating producers, performance data for all enrolled lambs will be summarized and shared with producers. Data will include dam and sire information, live lamb growth performance and feed efficiency information, carcass data, sensory performance, and chemical analysis results (i.e., crude protein value, crude fat value, etc.) at the end of year 2.
A regional field day will be organized at the end of year 2 that will include:
- presentation of results from the producer centered research trial,
- topics from the previous survey will be used to develop an interactive needs-based curriculum at the field day,
- demonstrate prediction equations and calculators, followed by an interactive producer session in which a current supply of computer tablets owned by the University of Wyoming Animal Science Department will be distributed to producers for each to enter actual data from their flocks to predict optimal harvest weight using developed prediction equations and calculators,
- a sensory demonstration involving remaining loin samples for producers to actually taste products from producer lambs involved in the research trial,
- producer responses from the sensory demonstration of remaining producer lamb loin chops from each live animal diet will be collected to support additional material development and to support submission of a scientific publication,
- on-campus extension specialists and state-wide or regional-wide extension educators will be incorporated into the field day,
- a pre-post survey and WSARE survey will be distributed at the regional field day event to capture assessment information.
A recorded webinar will be distributed to reach a larger, national Katahdin producer audience to expand impact of the research findings and educational tools developed. As part of the recorded webinar, the project team will highlight successes from the producers that changed management or marketing strategies based on the research and educational components of this project. This webinar will be archived on the University of Wyoming Extension YouTube page and on the University of Wyoming Animal Science Extension Page during year 2.
At least 40 Intermountain West and regional field day attendees will become knowledgeable about best practices for producing harvest Katahdin lambs during year 2 and 3.
Field day attendees will understand, and understand how to use, prediction equation and calculator resources.
Field day attendees will be able to highlight developed materials during the subsequent Rocky Mountain Katahdin Association meeting and/or national Katahdin Association meeting.
During Year 2, participating producers will submit forage and/or feed samples to the research team at the University of Wyoming to organize, send for forage/feed analysis and share results with producers.
During Year 2 and 3, regional and national Katahdin producers will be able to submit management information, live animal performance (ex. harvest weight) and carcass information (ex. carcass weight, final product yield, etc.) to compare to research lamb data from year 1. During Year 2 of the project, producers will submit live animal scores and live body weights for validation of use of online calculators. Data submitted by producers from processing facilities including hot carcass weight and yield of products will be used to evaluate target body weight adoption.
A final survey (post-project survey) will be distributed to producers to evaluate adoption and implementation of materials developed from this project (i.e., harvest weight prediction calculator).
A minimum of 3 factsheets will be developed from this project consisting of:
- Comparison of growth rate and performance information, carcass characteristics and sensory information for Katahdin lambs that were grass-fed, backgrounded (i.e., grass-fed) followed by grain-feeding and grain-fed.
- Prediction equation for optimal harvest lamb weight based on dam and sire information specific to the Katahdin breed.
- Optimizing forage and grazing resources to maximize Katahdin lamb growth.
- Online calculators such as a harvest weight prediction calculator will be developed and housed on the UW-Animal Science-Extension webpages for producers to use.
Recorded webinars will be added to the UW-Animal Science-Extension webpages from topics presented at the field day event.
A manuscript of results from this project will be constructed and submitted to a scientific journal for publication (i.e., Journal of Animal Science or similar scientific journal) during year 3.
Expected outcomes of this producer integrated research and education program include producer adoption of prediction equations and calculators to utilize with actual flock data during years 2 and 3 of the program. An important expected outcome is high regional and national participation from Katahdin producers in field day and webinar events. Research findings from the feeding trial during Year 2 is expected to inform collaborating producers on this project (Fief, Blosser, Norris) to increase future participation in research and extension efforts among more producers. A publication of findings from the research trial is also expected to support management strategies as well as inform future research objectives.
An institutional review board (IRB) exemption protocol (protocol #20240202CG03721) was approved by the University of Wyoming IRB for survey #1 and subsequent approval will occur prior to additional surveys utilized in this project.
Year 1 Accomplishments
This grant entitled 'Enhancing producer decision making: Lamb feeding strategies and meat quality assessment in the Katahdin sheep breed' was approved and started on September 5, 2023. A new M.S. graduate student started her program with a focus on this work. Data from this study will be used in her M.S. Thesis and in publications (scientific journal and extension products). To address Educational Objectives 2 and 3 [2) evaluate current management and marketing strategies used by producers in the intermountain-west region, 3) provide effective education utilizing interactive management tools developed through this project), producer members of this grant were integrated into the project planning and administration of the entire project. Due to the time of the calendar year that lambs are born, substantial planning efforts occurred between the grant start date of 9/5/23 and this spring to secure producer lambs for the research trial occurring during summer-fall 2024. As part of these planning activities, approximately 400 producers have been contacted with information about the research and education objectives of this project along with a comprehensive producer survey (both mailed and electronic versions; IRB protocol #20240202CG03721). Several survey responses have already been returned. In addition, numerous producers in addition to the participating producers on this grant have committed to enrolling lambs for the research objectives of this grant. Upon summarizing final survey results Spring/Summer 2024, informational webinars will be conducted for producers to share results and initial management tools developed. In addition, Katahdin production records are being analyzed to contribute to development management tools.
Since September 2023, we focused on constructing and disseminating the primary producer survey that is being used to develop producer webinars and tailored management tools. Through the producer contact and survey activities, we expanded the number of participating producers that are currently enrolling lambs into the research trial beginning Summer 2024. Through these planning and contact activities, we expanded involvement to a wider, regional and national audience of Katahdin producers. Primary education and outreach activities are being scheduled for online webinar launching during Fall 2024. Multiple phone calls with the planning committee (participating producers on this grant) and expanded producers occurred during Spring 2024. As survey results are summarized, including data from individual producers, educational materials will be developed and provided to producers for initial utilization.
Education and Outreach Outcomes
In the first seven months of the project, we focused on working with our producer partners to plan the educational and research activities as well as construct and disseminate the primary producer survey that is being used to develop producer webinars and tailored management tools. Through our producer contact and survey activity, we expanded the number of participating producers that are currently enrolling lambs into the research trial beginning Summer 2024. These planning and contact activities resulted in expanded involvement to a wider, regional and national audience of Katahdin producers.