Meat Science Commons^™

2024 Cattlemen's Day Full Report

Kansas Agricultural Experiment Station Research Reports

This report includes research conducted in 2023 on beef cattle management, nutrition, and meat science conducted at Kansas State University. Specific topics include effects of prescribed burning and grazing in the Flint Hills, managing livestock pests with prescribed range burning, feeding techniques and methods in feedlots, nutrition supplements for improved health management, and beef thawing methods and consumer palatability preferences.

The Effects Of Thawing Method On Consumer Palatability Ratings Of Beef Strip Loin Steaks, Stephanie L. Witberler, Lindsey K. Decker, Erin S. Beyer, Morgan D. Zumbaugh, Michael D. Chao, Jessie L. Vipham, Travis G. O'Quinn

Kansas Agricultural Experiment Station Research Reports

Objective:The objective of this study was to determine palatability differences in beef strip loin steaks among various U.S. Department of Agriculture approved thawing methods and those commonly utilized by consumers.

Study Description:Paired Low Choice beef strip loins (n=15) were collected and fabricated into six sections, each section was fabricated into 1-in steaks and assigned one of six thawing methods including: countertop, cook from frozen, cold water, hot water, microwave, and refrigerator. Steaks were cooked to an internal peak temperature of 160°F and consumers were given samples which they evaluated for juiciness, tenderness, flavor liking, overall liking, …

A Novel Approach Of Using Electrostatic Field To Reduce Thawing Time And Improve Frozen Beef Quality, Grace E. Corrette, Haley J. Jeneske, Sara R. Hene, Linnea A. Rimmer, Larissa A. Koulicoff, Morgan D. Zumbaugh, Travis G. O'Quinn, Scott J. Eilert, Bret Flanders, Michael D. Chao

Kansas Agricultural Experiment Station Research Reports

Objective:The objective of this study was to evaluate the impact of applying an electrostatic field (EF) on thawing characteristics, such as thawing speed and purge loss, as well as its impact on quality attributes during subsequent aging and retail display of beef.

Study Description:Striploins from both sides of USDA Choice carcasses (n = 12) were collected and portioned into four equal parts (n = 48). Portions were vacuum packaged and frozen at -40°F for 14 days and randomly assigned to one of four EF thawing treatments: 0 kV (control), 2.5 kV (EF-2.5), 5 kV (EF-5), and 10 kV …

The Effects Of Thawing Methods On Trained Sensory Evaluation Of Beef Palatability Traits And Instrumental Measurements Of Quality, Lindsey K. Decker, Erin S. Beyer, Michael D. Chao, Morgan D. Zumbaugh, Jessie L. Vipham, Travis G. O'Quinn

Kansas Agricultural Experiment Station Research Reports

Objective:Using beef strip loins steaks, evaluate six common thawing methods and assess the quality attributes through a trained panelist evaluation and an array of instrumental quality measures.

Study Description:Paired Low Choice strip loins (n = 15) were collected from a beef packing facility. The paired loins were fabricated into 1-in steaks and blocked into six blocks of four steaks. Each block was assigned a different thawing method, and each steak within the block a test, then aged 21 days and frozen. Thaw methods consisted of the four USDA-approved thaw methods: refrigerator (REF), cold water (CW), microwave (MIC), cooking …

Evaluation Of Thawing Curves Of Beef Strip Loin Steaks Using Various Thawing Methods, Lauren M. Frink, Lindsey K. Decker, Erin S. Beyer, Michael D. Chao, Morgan D. Zumbaugh, Jessie L. Vipham, Travis G. O'Quinn

Kansas Agricultural Experiment Station Research Reports

Objective:The objective of this study was to evaluate and determine thaw rate and time of strip steaks thawed using methods that are recommended by the U.S. Department of Agriculture and those commonly used by consumers.

Study Description:Strip steaks collected from a beef packing facility were randomly assigned a thaw method. Initially, steaks were vacuum packaged and then frozen at -40°F until thawed. Two thawing methods were USDA-approved: thawing in a refrigerator (REF) and in cold water (CW); while the other two methods evaluated are commonly used by consumers: thawing on the countertop (CT) and in hot water (HW). …

The Effects Of Sous Vide Cooking And Cysteine Proteases On Instrumental And Sensory Textural Properties Of Lower Value Cuts Of Beef, Ian Smith

All Theses

Sous vide cooking has the potential to increase the value of lower quality cuts of beef. Understanding the textural properties following a cook-chill sous vide process is crucial to maximizing this potential. The use of enzymes may further increase the value of these products if able to positively alter the texture of the final product.

The first research objective was to use instrumental texture analysis to evaluate potential relationships between enzymatic treatments and sous vide processing time of lower value cuts of beef. Three cuts were evaluated: infraspinatus (top blade), semitendinosus (eye of round), and beef tongue. Infraspinatus and semitendinosus …

Measuring The Phytochemical Richness Of Meat: Effects Of Grass/Grain Finishing Systems And Grapeseed Extract Supplementation On The Fatty Acid And Phytochemical Content Of Beef, Lucas Krusinski, Isabella C. F. Maciel, Stephan Van Vliet, Muhammad Ahsin, Guanqi Lu, Jason E. Rowntree, Jenifer I. Fenton

Nutrition, Dietetics, and Food Sciences Faculty Publications

Grass-finished beef (GFB) can provide beneficial bioactive compounds to healthy diets, including omega-3 polyunsaturated fatty acids (n-3 PUFAs), conjugated linoleic acid (CLA), and secondary bioactive compounds, such as phytochemicals. The objective of this study was to compare fatty acids (FAs), micronutrients, and phytochemicals of beef fed a biodiverse pasture (GRASS), a total mixed ration (GRAIN), or a total mixed ration with 5% grapeseed extract (GRAPE). This was a two-year study involving fifty-four Red Angus steers (n = 54). GFB contained higher levels of n-3 PUFAs, vitamin E, iron, zinc, stachydrine, hippuric acid, citric acid, and succinic …

Texas A&M Beef Cattle Short Course: Program Evaluation, Nicola Oosthuizen, Pedro Fontes, Graham C. Lamb, Jason J. Cleere

The Journal of Extension

Survey results (n = 3,748) collected over a period of 7 years from the Texas A&M Beef Cattle Short Course (BCSC) were analyzed to evaluate course demographics and the impact of the course on attendees. Results of this survey demonstrate that attendee demographics of the BCSC are representative of beef cattle producers in the United States and that the BCSC is effective at delivering information that positively impacts beef production in Texas. Extension professionals can make use of these findings to tailor future education programs to better serve the needs of beef cattle producers nation-wide.

2023 Cattlemen’S Day Full Report, Liz Boyle

Kansas Agricultural Experiment Station Research Reports

This report includes research conducted in 2022 on beef cattle management, reproduction, nutrition, and meat science conducted at Kansas State University.

Consumer Color And Discoloration Thresholds For Purchase Of Retail Ground Beef When Evaluating Packages Of A Single Day Of Display, K. R. Lybarger, E. S. Beyer, K. J. Farmer, L. A. Egger, L. N. Drey, J. L. Vipham, M. D. Zumbaugh, M. D. Chao, T. G. O'Quinn

Kansas Agricultural Experiment Station Research Reports

Objective:This study utilized a simulated retail display to investigate the impact of ground beef color and discoloration on consumer purchase intent, while identifying the best objective measurements to predict consumer preferences of ground beef on the same day of retail display.

Study Description:For this study, 180 1-lb 80% lean/20% fat ground beef loaves were assigned to a specific day of retail display (day 0–9). Consumers (n= 318) and trained descriptive panelists assessed ground beef samples, with a single day of display evaluated per consumer group. Spectral data andL*(lightness),a* (redness), andb* (yellowness) …

Change In Myoglobin Denaturation Among Three Degrees Of Doneness Of Three Muscles, E. S. Beyer, K. J. Farmer, E. G. Kidwell, S. G. Davis, K. M. Harr, K. R. Lybarger, L. A. Egger, M. D. Chao, M. D. Zumbaugh, J. L. Vipham, M. C. Hunt, T. G. O'Quinn

Kansas Agricultural Experiment Station Research Reports

Objective:The objective of this study was to determine the changes in myoglobin denaturation through cooking three different muscles to medium rare, medium, or well-done degrees of doneness.

Study Description:Strip loins (n= 12) and top butts (n= 12) were used to evaluate the physiochemical properties of thelongissimus dorsi, biceps femoris,andgluteus mediusfor three degrees of doneness (DOD; medium rare, medium, and well-done).

The Bottom Line:As expected, the myoglobin denaturation percentage increased with increasing DOD and behaved similarly to changes in the a* values. This research gives more insight into the impacts of cooking …

Effects Of Adding Egg Powder From Hens Immunized Against Phospholipase Α2 On Ground Striploin Shelf Life, C. Velasco Ayala, L. A. Koulicoff, C. K. Chun, T. G. O'Quinn, E. Boyle, M. Richards, C. K. Jones, M. D. Chao

Kansas Agricultural Experiment Station Research Reports

Objective:The present study investigated the effect of incorporating three different levels of dried egg powder (EP) containing antiphospholipase α2 (aPLA2) on lipid oxidation and discoloration for its potential to extend ground striploin shelf life.

Study Description:U.S. Department of Agriculture choice striploins from ten beef carcasses were used. Impacts on beef discoloration, L* (lightness), a* (redness), and b* (yellowness) parameters, and lipid oxidation over a 7-day display period were studied. The fatty acid and phospholipid profiles of the beef patties were also examined.

Results:The EP was confirmed to contain active aPLA2. As expected, a* and b* values decreased …

Consumer Sensory Evaluation Of Ground Beef And Plant-Based Ground Beef Alternatives Used In A Hamburger Application, L. A. Egger, K. J. Farmer, E. S. Beyer, K. R. Lybarger, J. L. Vipham, M. D. Zumbaugh, M. D. Chao, T. G. O'Quinn

Kansas Agricultural Experiment Station Research Reports

Objective:The objective of this study was to evaluate the palatability traits and consumer acceptance of three plant-based ground beef alternatives in comparison to ground beef in a foodservice-like hamburger application.

Study Description:Three popular plant-based ground beef alternatives (GBA) and 80% lean, 20% fat composition ground beef chubs (n = 20) were selected for consumer analysis. Samples were cooked to an internal temperature of 160°F, plated on a bun and served to consumers with the opportunity to apply ketchup, mustard, cheese, lettuce, and pickles. Consumers evaluated the differences in palatability traits and purchase intent for the samples identified as: …

Determination Of Consumer Color And Discoloration Thresholds For Purchase Of Retail Ground Beef When Evaluating Multiple Days Of Display Simultaneously, K. R. Lybarger, E. S. Beyer, K. J. Farmer, L. A. Egger, L. N. Drey, J. L. Vipham, M. D. Zumbaugh, M. D. Chao, T. G. O'Quinn

Kansas Agricultural Experiment Station Research Reports

Objective:The objective of this study was to identify the threshold for color and discoloration for consumers to purchase ground beef in a simulated retail display and to determine the best objective measurement to predict consumer purchase intent.

Study Description:For this study, 180 1-lb 80% lean/20% fat ground beef packages were assigned to a day of retail display (day 0–9). Consumers (n = 216) and trained descriptive panelists evaluated ground beef samples from each day of display simultaneously. InstrumentalL*(lightness), a*(redness),andb*(yellowness) values were collected, and spectral data were recorded. Logistic and simple …

Evaluation Of Kansas Beef Consumers’ Awareness And Understanding Of Business-To-Consumer Marketing, L. K. Decker, K. R. Lybarger, J. Kwon, G. Ibendahl, Y. Teng-Vaughan, D. Kehler, T. G. O'Quinn

Kansas Agricultural Experiment Station Research Reports

Objective:The objective of the study was to determine the understanding and knowledge level of consumers purchasing beef in a business-to-consumer (B2C) format within Kansas.

Study Description:A digital survey was created to evaluate consumers’ familiarity and satisfaction of buying beef in a B2C format. The survey was made available for a two-week period to consumers utilizing the Shop Kansas Farms online social media group.

Results:Results of the survey showed 93% of consumers (n = 174) reported having previously purchased beef products from a local producer or locker. Of these, 63.1% reported that their most recent purchase was their …

Assessment Of Kansas Beef Producers’ Perception And Knowledge Level Of Business-To-Consumer Marketing, K. R. Lybarger, J. Kwon, G. Ibendahl, Y. Teng-Vaughan, D. Kehler, T. G. O'Quinn

Kansas Agricultural Experiment Station Research Reports

Objective:The objective of this study was to assess the perception and knowledge level of Kansas beef producers regarding business-to-consumer marketing.

Study Description:A digital survey was created to assess the perception and knowledge level of business-to-consumer (B2C) marketing of Kansas beef producers. The survey was disseminated to Kansas beef producers utilizing the Shop Kansas Farms online social networking group.

Results:Results from this study showed that 25.5% of beef producer respondents (n = 41) raise another species in addition to beef. It was found that 50.0% of survey respondents sold 20 or fewer head of finished beef cattle in …

Consumer Sensory Evaluation Of Ground Beef And Plant-Based Ground Beef Alternatives Used In A Taco Application, L. A. Egger, K. J. Farmer, E. S. Beyer, K. R. Lybarger, J. L. Vipham, M. D. Zumbaugh, M. D. Chao, T. G. O'Quinn

Kansas Agricultural Experiment Station Research Reports

Objective:The objective of this study was to evaluate consumer preferences for palatability traits and consumer acceptability of three plant-based protein alternatives and ground beef in a taco application.

Study Description:Three commercially available plant-based ground beef alternative (GBA) treatments (n = 20) were selected based upon industry prevalence. The GBAs’ were identified as the most popular in the marketing sectors of foodservice (FGBA), retail (RGBA), and traditional (TGBA). One ground beef (80% lean; 20% fat) treatment (n = 20) was selected. Samples were crumbled into a skillet and cooked to a surface temperature of 180°F. Following cooking, a generic …

Establishing Spoilage Thresholds Of Ground Beef In A Traditional Retail Case Scenario, G. E. Corrette, E. S. Beyer, E. A. Mendez, V. Hay, T. G. O'Quinn, M. D. Chao, J. L. Vipham

Kansas Agricultural Experiment Station Research Reports

Objective:The objective of this study was to determine spoilage in fresh ground beef and the perception of consumers regarding alteration of sensory characteristics, as well as the acceptability at different days of shelf-life.

Study Description:Ground beef loaves (n= 84) of 80% lean, 20% fat composition and aerobically packaged were stored in a simulated refrigerated retail case for 6 days. Consumers evaluated visual color, odor, touch, and taste. Instrumental color, lipid oxidation, aerobic plate count, andEnterobacteriaceaecount were determined.

The Bottom Line:In this study, color was shown to be the important product characteristic of spoilage to …

Evaluating The Effect Of Accelerated Aging At Different Temperature And Time Points On Beef Quality And Enzyme Activity Of Lower Quality Beef Cuts, H. Jeneske, C. K. Chun, S. Hene, L. A. Koulicoff, H. Aufdemberge, J. L. Vipham, T. G. O'Quinn, M. D. Chao

Kansas Agricultural Experiment Station Research Reports

Objective:This study aimed to explore the effects of four accelerated aging (AA) methods at different temperature and time points on meat quality and enzymatic activity of two lower quality beef cuts.

Study Description:Shoulder clod and top round were collected from 10 U.S. Department of Agriculture choice beef carcasses, fabricated into steaks, and assigned to one of six treatments: 3 days postmortem (control), cooler aged for 21 days, AA 120°F for 2 h, AA 120°F for 3 h, AA 130°F for 2 h, and AA 130°F for 3 h. Yield was calculated based on loss during AA and cooking …

Evaluation Of Bovine Myosin Heavy Chain Isoforms And Muscle Fiber Cross-Sectional Area On The Eating Quality Of 11 Different Beef Muscles, S. Hene, H. Ness, E. Verrill, P. A. Hammond, C. K. Chun, T. G. O'Quinn, M. D. Chao

Kansas Agricultural Experiment Station Research Reports

Objective:The objective of this study was to investigate the contribution of muscle fiber type and size on the eating quality of 11 different beef muscles.

Study Description:Eleven different beef muscles were utilized from two separate studies. In study 1, shoulder clod, flank, knuckle, mock tender, top sirloin butt, brisket, eye of round, and ribeye were collected from 10 U.S. Department of Agriculture choice carcasses (n = 80), and each muscle was fabricated into steaks at 2 days postmortem. In study 2, strip loin, tri-tip, and heel were collected from 10 USDA low choice carcasses (n = 30). Myofibrillar …

Consumer Sensory Evaluation Of The Impact Of Bone-In Versus Boneless Cuts On Beef Palatability, K. J. Farmer, E. S. Beyer, S. G. Davis, K. M. Harr, M. D. Chao, J. L. Vipham, M. D. Zumbaugh, T. G. O'Quinn

Kansas Agricultural Experiment Station Research Reports

Objective:The objective of this study was to determine palatability traits of beef cuts of differing bone status and quality grade.

Study Description:Paired (n = 12 pairs; 24 total/cut/grade) boneless and bone-in ribeye rolls, and short loins were procured. Short loins were fabricated into boneless strip loins with corresponding bone-in tenderloins or bone-in strip loins with boneless tenderloins. Post aging, subprimal cuts were fabricated into steaks that were randomly selected for further analysis. Consumer sensory panelists (n = 144) were recruited from Manhattan, KS, and the surrounding area and paid for their participation in the study. Panels were conducted …

Microbial Community Structure From Southern High Plains Beef Cattle Feedyard Manure And Relationship With Nitrous Oxide Emissions, Heidi Waldrip, David Parker, Sierra Miller, Lisa M. Durso, Byeng R. Min, Daniel N. Miller, Kenneth Casey, Bryan Woodbury, Mindy J. Spiehs

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Modern molecular techniques enable characterization of the microbial biome in livestock manure, from which there is particular concern over emission of greenhouse gases. This study evaluated how sampling depth, time, temperature, and artificial rainfall affected microbial community structure in feedyard manure, and relationships between the manure biome and known parameters related to nitrous oxide (N₂O) emissions. In three large incubation chambers, maintained at different temperatures that received two applications of artificial rainfall, we evaluated manure microbiome composition and abundance of N₂O-producing enzymes (nirK and nirS) using quantitative polymerase chain reaction (qPCR). These data were …

Inosine 5’- Monophosphate Derived Umami Flavor Intensity Of Beef Determination By Electrochemistry And Chromatography, Kezia Virellia To

Theses and Dissertations

The umami sensation contributes to beef flavor and acceptability. Inosine 5’- monophosphate (IMP) was the most abundant nucleotide in meat known to impart umami taste which thus far had been overlooked in meat flavor studies. The objectives of this study were to determine the umami taste threshold of inosine 5'-monophosphate (IMP), the effects of spiking IMP on the sensory descriptive attributes of various USDA graded beef strip steaks, and to differentiate beef by IMP content using electrochemistry. USDA Prime, Choice, and Select steaks were spiked with 0.3 and 0.6 mM IMP and analyzed chemically and organoleptically. Liquid chromatography-mass spectrometry and …

Evaluating The Shelf Life And Sensory Properties Of Beef Steaks From Cattle Raised On Different Grass Feeding Systems In The Western United States, Toni L. Duarte, Bakytzhan Bolkenov, Sarah C. Klopatek, James W. Oltjen, D. Andy King, Steven D. Shackelford, Tommy L. Wheeler, Xiang Yang

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Consumer interest in grass-fed beef has been steadily rising due to consumer perception of its potential benefits. This interest has led to a growing demand for niche market beef, particularly in the western United States. Therefore, the objective of this study was to assess the impact of feeding systems on the change in microbial counts, color, and lipid oxidation of steaks during retail display, and on their sensory attributes. The systems included: conventional grain-fed (CON), 20 months-grass-fed (20GF), 25-months-grass-fed (25GF) and 20-months-grass-fed + 45-day-grain-fed (45GR). The results indicate that steaks in the 20GF group displayed a darker lean and fat …

Genes Involved In Feed Efficiency Identified In A Meta-Analysis Of Rumen Tissue From Two Populations Of Beef Steers, Amanda K. Lindholm-Perry, Allison M. Meyer, Rebecca J. Kern-Lunbery, Hannah C. Cunningham-Hollinger, Taran H. Funk, Brittney N. Keel

Roman L. Hruska U.S. Meat Animal Research Center: Reports

In cattle, the rumen is an important site for the absorption of feed by-products released by bacterial fermentation, and variation in ruminal function plays a role in cattle feed efficiency. Studies evaluating gene expression in the rumen tissue have been performed prior to this. However, validating the expression of genes identified in additional cattle populations has been challenging. The purpose of this study was to perform a meta-analysis of the ruminal transcriptome of two unrelated populations of animals to identify genes that are involved in feed efficiency across populations. RNAseq data from animals with high and low residual feed intake …

Prenatal Transportation Stress Did Not Impact Ovarian Follicle Count For Three Generations Of Female Brahman Offspring, Lacey K. Quail, Ronald D. Randel, Thomas H. Welsh Jr., Robert A. Cushman, Hannah K. Yake, Rui A. D'Orey Branco, Donald A. Neuendorff, Charles R. Long, George A. Perry

Roman L. Hruska U.S. Meat Animal Research Center: Reports

As prenatal transportation stress altered behavior and adrenal glucocorticoid secretion of calves, we hypothesized that prenatal transportation stress would decrease ovarian reserve size and negatively impact female offspring fertility. The impact of prenatal transportation stress on ovarian follicle numbers in female offspring for three generations was studied. Brahman cows were transported for 2 h on day 60 ± 5, 80 ± 5, 100 ± 5, 120 ± 5, and 140 ± 5 of gestation. Ovaries were collected from offspring of transported or non-transported dams at multiple ages. Primordial, primary, secondary, and antral follicles were histologically analyzed. Antral follicle numbers were …

Efficacy Of Antimicrobial Interventions Used In Meat Processing Plants Against Antimicrobial Tolerant Non–Antibiotic-Resistant And Antibiotic-Resistant Salmonella On Fresh Beef, Norasak Kalchayanand, Sapna Chitlapilly Dass, Yangjunna Zhang, Eric L. Oliver, Bing Wang, Tommy L. Wheeler

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Salmonella is a common cause of foodborne illness in the United States, and several strains of Salmonella have been identified as resistant to antibiotics. It is not known whether strains that are antibiotic resistant (ABR) and that have some tolerance to antimicrobial compounds are also able to resist the inactivation effects of antimicrobial interventions used in fresh meat processing. Sixty-eight Salmonella isolates (non-ABR and ABR strains) were treated with half concentrations of lactic acid (LA), peracetic acid (PAA), and cetylpyridinium chloride (CPC), which are used in beef processing plants to screen for tolerant strains. Six strains each from non-ABR and …

Effects Of Administration Of A Growth Promoting Implant During The Suckling Phase Or At Weaning On Growth, Reproduction, And Ovarian Development In Replacement Heifers Grazing Native Range, Shelby L. Rosasco, Emily A. Melchior-Tiffany, Cierrah J. Kassetas, Shad H. Cox, Richard L. Dunlap, Jennifer A. Hernandez Gifford, Eric J. Scholljegerdes, Robert A. Cushman, Adam F. Summers

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Management strategies utilized during pre-breeding development of replacement heifers can impact fertility and the ovarian reserve. Angus- Hereford crossbred heifers (n = 233) were utilized over a 3-yr period to determine the effects of administration of a growth promoting implant at either branding or weaning on growth, reproduction, and ovarian development. Heifer calves were randomly assigned to one of three treatments: 1) nonimplanted controls (CON; n = 79), 2) implanted at approximately 2 mo of age (average calf age = 58 d) with Synovex-C (BIMP, n = 82), or 3) implanted at approximately 7 mo of age (average calf …

Interaction Of Replacing Corn Silage With Soyhulls As A Roughage Source With Or Without 3% Added Wheat Straw In The Diet: Impacts On Intake, Digestibility, And Ruminal Fermentation In Steers Fed High-Concentrate Diets, Bryan W. Neville, Wayde J. Pickinpaugh, Lea J. Mittleider, Rebecca L. Moore, Kendall C. Swanson, Joel S. Caton

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Six ruminally cannulated steers [475.0 ± 49.6 kg initial body weight (BW)] were used in a 6 × 3 incomplete Latin square design (six treatments and three periods), to evaluate the impacts replacing of corn silage with pelleted soyhulls as roughage in high-concentrate finishing diets containing 30% modified distillers grains with solubles. Treatments were based on increasing dietary inclusion of soyhulls and consisted of: (1) Control (0), roughage supplied by dietary inclusion of 20% corn silage [dry matter (DM) basis]; (2) 50% replacement of corn silage with soyhulls (50); (3) 100% replacement of corn silage with soyhulls (100), and the …

Development And Validation Of High-Resolution Melting Assays For The Detection Of Potentially Virulent Strains Of Escherichia Coli O103 And O121, Frank J. Velez, Joseph M. Bosilevac, Sabine Delannoy, Patrick Fach, Ravinder Nagpal, Prashant Singh

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Virulent strains of Shiga toxin-producing Escherichia coli (STEC) serogroups O103 and O121 are considered adulterants in beef. Two high-resolution melting (HRM) real-time PCR assays were standardized for the specific detection and discrimination of potentially virulent and avirulent strains of E. coli O103 and O121. The O103 HRM assay offered the possibility to distinguish clearly STEC O103:H2 from STEC O103:H25. The two standardized assays were extensively validated using 215 pure culture strains, laboratory inoculated food samples, and naturally contaminated beef (n = 84) and pork (n = 84) enrichments collected from the red meat surveillance program. Both HRM assays showed 100% …