University of Wyoming

Recent industry-wide evaluations have identified the critical challenge that over-fat-lambs pose to the industry, but have not to date quantified these losses within the packing sectors. We acknowledge the problem can be attributable to all aspects of the industry (e.g. producer, feedyard, packer), and the inherent seasonality of production in the U.S. Sheep Industry. Nevertheless, these fat-related losses culminate at the packing phase, and thereby provide an opportunity to quantify these losses at that point. Thus, we propose a pilot-study to quantify the economic losses due to overfat lambs at two packing plants in Colorado to provide baseline estimates of losses at the processing phase. We propose to accomplish this objective through within plant survey methods, data collection on the fabrication floor, and economic modeling. Thus, the anticipated outcome of the proposed research is to provide the U.S. sheep industry a quantitative assessment of what over-fat lamb is costing the meat processing sector as a basis for future assessments across other sheep industry sectors.
We propose a “phase 1” pilot-study to quantify the economic losses due to overfat lamb at the two of the major packing plans. To accomplish this objective, we will use survey methods, historical data analysis, and data collection on the fabrication floor. Thus, the anticipated outcome of the proposed research is to provide the U.S. sheep industry a quantitative assessment of what over-fat lamb is costing the meat processing sector. Specific Aims: • Collect carcass measurements to estimate quantity and distribution of yield grades during peak “fat-prone” harvesting periods. • Determine fat losses in cutout data and combined labor hours and other inputs related to trimming and disposing of fat • Economic modeling to determine industry costs and projected improvements

Study logistics and Packing Plant Coordination (Spring 2018): • Integration of research protocol with plant operations will be refined to ensure collection of data according to study design • Evaluation of necessary modeling and statistical components from data available

Packing Plant Data Collection and Analysis (May to September 2018):
Project participants will base research investigations within the Mountain States Rosen plant Greeley, CO, and Superior Farms plant in Denver, CO in coordination with plant personnel.
• Subsample lamb carcasses for objective measurement to accurately estimate distribution of yield grades during the season where harvest of fat lambs is most abundant • Follow a subsample of YG 2-5 through fabrication to determine relative trim loss. • Specifications for trimming primal cuts to determine 1. Labor hours/resources committed to trimming to a specified fat thickness 2. Determine cost of disposing of fat carcasses. 3. Price differentials according to specified levels of trim per cut 4. Analyze (where available) historical information to estimate additional cut out losses

Economic and Statistical Modeling (September 2018 to February 2019):
For all economic modeling a Monte Carlo approach will be utilized to look at a variety of economic scenarios (input/output price combinations) based on historical outcomes to determine the distribution of potential economic outcomes. From this we can look at what cost scenarios exist when distribution of YG 4 and 5’s varies, coupled with varying price structure discounts. Statistical analysis employed will include mixed linear models determine differences in cutout information and any historical data available for analysis. Distribution of actual measured yield grades and their correlation corresponding USDA grading data available will also be analyzed. Reporting-Anticipated Results (March to May 2019):
A technical report with study findings will be generated to discuss project outcomes in addition to a peer reviewed publication. Findings will also be shared with stakeholder audiences and committees at the American Sheep Industry Association meetings, and local state meetings. Once data has been interpreted and summarized for industry, key stakeholders will convene to evaluate future approaches in the lamb feeding and producer sectors.

NSIIC September Progress Report

University of Wyoming- Quantifying the economic impact of excessively fat lambs in U.S. processing


Summer data collection for the “Cost of Over- Fat Lamb Project” is slowing down as the

fall semester at the University of Wyoming starts back up. Since May 24, 2018, we have

collected approximately 7,000 images of carcass rib-eyes that had been ribbed between the 12th

and 13th rib. Luckily, we have reached the downhill slide of picture analysis with 2,009 images

left to be analyzed using Image J software. Throughout the last month, we have had the

opportunity to expand the project onto both the kill floor and fabrication to quantify

inefficiencies caused by overfat lambs.

As our research team became more familiar with the operations of Mountain States

Lamb, we began digging deeper into the fat lamb problem and were informed that the kill floor

also suffers when extremely large lambs are processed. Plant personnel expressed that problems

arise in three major places on the kill floor: the loading chute, the wide to narrow machine, and

the hide pullers. We took initiative to expand the project by collecting timing data from 9 lots

over a two week period. Total kill floor completion time (from the loading chute to the camera

grade), number of re-stuns, number of mistakes by the wide to narrow machine, and number of

mistakes by the hide pullers were recorded. Mountain States mentioned that they would greatly

benefit from this kill floor information, and we are eager to evaluate the data.

On August 2, 2018, Drs. Whit Stewart, Warrie Means, John Ritten, and our student

research team had the opportunity to meet with a variety of personnel at Mountain States to

discuss other areas that face complications with excessively fat lambs including shipping,

maintenance, and human resources. Operational data needed to quantify the economic costs was

also discussed, and we should be receiving that information soon. Cost evaluation will

investigate accounting records, cost fluctuations throughout the year, maintenance records,

human resources statements, and any other data the plants will provide that will give us an

accurate idea of how operations change during “fat-lamb season.” Our meeting revealed how

every aspect of the processing sector faces adversities with excessively large lambs.

August 8-9th and 13-17th we were able to get into Superior Farms to collect both carcass

images and fabrication timing data. Just under 2,000 images of carcasses were recorded as they

moved into the fabrication line throughout the week. Fabrication timing was also evaluated as

planned in the original fabrication timing protocol. Superior Farms was gracious enough to sort

50 heavy weight carcasses (100-150 lb.) and 50 of light weight carcasses (60-80 lb.) to run

through fabrication. Lines were cleared before and after each set of 50. When each group of

carcasses had been fabricated fat and bone waste was weighed to quantify the amount of waste.

Unfortunately, the unpredictable nature of an industry level study posed challenges we had to

overcome. Commercial slaughter plants operations are dynamic in nature and change day to day.

Mechanical malfunctions to operational changes, and ultimately being at the mercy of plant

personnel results in adaptations. We faced some of these challenges while quantifying run time

differences between heavy and light carcass groups. Orders change daily affecting fabrication

specs, which was something that we couldn’t ask them to change. However, we did ask that they

keep the 50 heavy weight carcasses and 50 light weight carcasses similar in fabrication specs for

that day. There were also operational malfunctions that stopped production, but we are confident

that the timing data is still representative of commercial fabrication.

In summary, we are excited for the upcoming analysis, and the mountain of data that we

have compiled thus far. Although the majority of in-plant data collection is winding down, there

is still a large amount of economic data that will be analyzed to begin determining the monetary

cost of “excessively fat lambs.” Plans are currently being made to extend some data collection

into the fall/winter to compare carcass composition and time of fabrication of “current lamb

seasons” to the data collected during “peak over-fat lamb seasons.”

There is still a lot of work to go, but we are confident in our team and the information

that has been gathered. We are extremely appreciative of the plant personnel at Mountain States

Lamb and Superior Farms that have allowed us to work with them, and are enthusiastic to begin

working towards quantifying the cost of excessively fat lambs to the industry.
















Image 1: The protocol for capturing carcass images at the start of the fabrication process: 1) The

carcass tag is pulled and USDA YG from the back of the carcass is written on the tag, and 2) one

researcher captures the image while the other positions the tag on a ribeye grid and steadies the

















Image 2: This was the largest carcass we recorded this summer. It had a hot carcass weight of

188 lbs and USDA yield grade of 5. This lamb had an average rib eye area of 3.5 square inches,

average backfat thickness of 0.57 inches, and average body wall thickness of 1.9 inches (these

measurements are taken in duplicate). Despite having a break joint and being labeled lamb, this

animal has an estimated live weight of 355 lbs.













Image 3: During our roundtable discussion with Mountain States Lamb, we were informed that

their cost analysist found that the most profitable carcass weighs approximately 84 lbs hot

carcass weight and has a yield grade around 3.6. The carcass pictured above meets ideal backfat

measurements of 0.2 inches plus should be the most profitable for the plant as an 84 lb carcass

with a yield grade of 3.5. This carcass also has a ribeye area of 2.8 square inches.