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The objective of this study was to evaluate the effects of methionine supplementation prior to and during a lipopolysaccharide (LPS) challenge on the performance and inflammatory biomarkers of receiving beef steers. Steers ( n  = 65; 295.8 ± 46.5 kg) were randomly assigned to 3 treatment groups: L0 = Control, receiving no supplement; L1 = 10 g/hd/d rumen-protected methionine (MetaSmart, Adisseo USA Inc., Alpharetta, GA); and L2 = 20 g/hd/d rumen-protected methionine and fed for 40 d at the West Texas A&M University Research Feedlot. On day 40, a subset of steers ( n  = 32; L0 = 10; L1 = 11; L2 = 11) were transported to the USDA Livestock Issues Research Unit, and on day 41 steers were weighed and fitted with indwelling rectal thermometers and jugular catheters. On day 42, steers were challenged i.v. with LPS (0.25 µg/kg BW). Blood samples were collected at -2, 0, 2, 4, 6, 8, 10, 12, 18, 24, 36, and 48 h relative to the LPS administration at 0 h. Serum was isolated to determine serum chemistry and inflammatory marker concentrations. Whole blood was used for hematology analysis. There were no differences in DMI or ADG ( P  ≥ 0.75) during 35 d of supplementation. A treatment × time interaction ( P  = 0.01) occurred for rectal temperature, where L2 steers had the greatest temperature following the challenge ( P  ≤ 0.05) compared to L1 and L0 steers. There was a treatment × time interaction ( P  = 0.03) for the change in white blood cells where L0 steers had the greatest change compared to L1 and L2 steers at various timepoints. There was a treatment × time interaction ( P  = 0.02) for the change in tumor necrosis factor-α concentration, where there was a greater increase in concentration in L0 compared to L1 and L2 steers. Additionally, there was a treatment × time interaction ( P  < 0.01) for Macrophage Inflammatory Protein-1β (MIP-1β) concentrations, where concentrations were greater in L0 compared with L1 and L2 steers from 2 to 4 h post-challenge. There was a treatment × time interaction for plasma total protein concentration ( P  < 0.01) where L0 steers had less plasma total protein compared with L1 and L2 steers, while L1 steers had less plasma total protein than L2 steers at -2 h prior to LPS challenge. These data suggest that methionine supplementation may have an immunomodulatory effect in beef steers that may improve response to pathogens., (Published by Oxford University Press for the American Society of Animal Science 2024.)

Nutrient composition data that accurately represent available beef products are critical to understanding beef's role in healthy dietary patterns. The quality of beef products has changed over the past several decades, and updated nutrient data are warranted as USDA Prime beef cuts become more available. In an effort to provide a complete nutrient profile for frequently purchased USDA Prime beef cuts, five USDA Prime cuts; strip loin steak, tenderloin steak, ribeye steak, top sirloin steak, and rib roast were collected from retail stores in six geographical locations over three collections for macro- and micronutrient analysis in both the raw and cooked state. The separable lean portion of all analyzed USDA Prime cuts qualified as a good or excellent source, providing 10-19% or at least 20% of the daily value, respectively, for protein, niacin, vitamin B12, selenium, phosphorus, and zinc per FDA labeling claim standards. There was not a significant difference in cholesterol content between any of the cuts, raw or cooked ( p ≥ 0.44 and 0.34, respectively). The percent lipid in raw, separable lean portions of the rib roast and strip loin steak was significantly greater than the lipid portion in tenderloin and top sirloin steaks ( p ≤ 0.01). Per USDA standards, the separable lean portions of tenderloin steak and top sirloin steak qualify as lean beef, containing less than 10 g total fat, less than 4.5 g saturated fat, and less than or equal to 95 mg cholesterol. The current study provides the most up-to-date nutrient analysis for USDA Prime beef cuts, helping consumers and health professionals better identify the role of high-quality beef cuts in healthy dietary patterns.

Forty castrated Holstein calves underwent an adrenocorticotropic hormone (ACTH) challenge to assess the effects of premortem stress on the longissimus lumborum (LL) following harvest. LL biopsies were collected before the challenge, at different harvest times (2, 12, 24, and 48 h; n = 10), and after 14 d aging. The expression of small heat shock proteins (SHSPs), deglycase 1 (DJ-1), and troponin were analyzed. Blood was analyzed throughout the ACTH challenge and at harvest for cortisol, oxidative stress, and complete blood count (CBC). Color and myofibrillar fragmentation index (MFI) were measured in aged samples. Unexpectedly, calves from different harvest times differed ( p = 0.05) in cortisol response. Calves were divided into two different cortisol response groups (high or low; n = 20). Statistical analysis assessed the effects of cortisol response ( n = 20), harvest time ( n = 10), and their interaction. Harvest time altered SHSPs ( p = 0.03), DJ-1 ( p = 0.002), and troponin ( p = 0.02) expression. Harvest time and cortisol response impacted steak color ( p < 0.05), and harvest time altered steak pH ( p < 0.0001). Additionally, various CBCs were changed ( p < 0.05) by harvest time. Harvest time changed ( p = 0.02) MFI. These data demonstrate that the protein expression, color, and MFI of the LL may be influenced by premortem stress.

Historically, consumer acceptance of beef was determined by tenderness. Developments in genetics and management over the last couple of decades have improved tenderness to the point that it is secondary to other factors in beef's taste. Flavor, however, is an extraordinarily complex taste attribute dependent on biological sensors in the mouth, sinus cavity, and jaws. The culinary industry has recently focused on innovative ways to give consumers new products satisfying their curiosity about different foods, especially proteins. Competition from plant-based, cell-based, and even other animal-based proteins provides diversity in consumers' ability to select a protein that satisfies their desire to include unique products in their diet. Consequently, the beef industry has focused on flavor for the last 10 to 15 years to determine whether it can provide the guardrails for beef consumption in the future. The U.S. beef industry formed a Flavor Working Group in 2012 composed of the authors listed here to investigate new and innovative ways to manage and measure beef flavor. The results of this working group have resulted in dozens of papers, presentations, abstracts, and symposia. The objective of this manuscript is to summarize the research developed by this working group and by others worldwide that have investigated methodologies that measure beef flavor. This paper will describe the strengths of the research in beef flavor measurement and point out future needs that might be identified as technology advances., Competing Interests: Declaration of competing interest None., (Copyright © 2024. Published by Elsevier Ltd.)

The objective of this study was to evaluate the viability and performance of nitric oxide modified-atmosphere packaging (MAP) as a novel alternative to high oxygen and carbon monoxide MAP for ground beef. Packages of ground beef under high oxygen (HI-OX), carbon monoxide (CO), and nitric oxide (NO) atmospheres were evaluated for descriptive and instrumental color every 12 h during a 120 h display period. Surface myoglobin percentages, internal cooked color, thiobarbituric acid reactive substances (TBARS), and residual nitrite and nitrate were also evaluated. There were gas × time interactions for descriptive color, discoloration, a* values, b* values, deoxymyoglobin percentages, and metmyoglobin percentages ( p < 0.05). There were also gas-type main effects for cooked color and TBARS ( p < 0.05). Carbon monoxide maintained the most redness and least discoloration throughout the display period, while HI-OX started with a bright red color but rapidly browned ( p < 0.05). Nitric oxide started as dark red to tannish-red but transitioned to a dull red ( p < 0.05). However, NO had increased redness and a* values for internal cooked color ( p < 0.05). Although CO outperformed NO packages, NO exhibited a unique color cycle warranting further research to optimize its use.

Beef flavor continues to be one of the largest drivers of beef demand and a differentiation point of beef from other competing proteins. Tenderness has long been identified as the most important palatability trait for consumer satisfaction. However, as technological advancements and industry practices evolve and improve in response to tenderness management, flavor has emerged as a key driver of consumer satisfaction. In response, the beef industry has recently invested in research focused on beef flavor development, measurement, and management to better understand the factors impacting flavor and help beef maintain this advantage. The current review paper is the second of two such papers focused on summarizing the present knowledge and identifying knowledge gaps. While the other review focuses on current practices related to beef flavor measurement, this review will cover research findings related to beef flavor management. Numerous production and product management factors influence beef flavor. Pre-harvest factors including marbling level, animal genetics/cattle type, diet, and animal age, can influence beef flavor. Moreover, numerous post-harvest product management factors, including product type, aging length and conditions, cookery methods, product enhancement, muscle-specific factors, packaging, retail display factors, and antimicrobial interventions, have all been evaluated for their impact on beef flavor characteristics. Results from numerous studies evaluating many of these factors will be outlined within this review in order to present management and production chain factors that can influence beef flavor., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Multidrug resistant (MDR) Escherichia coli threaten the preservation of antimicrobials to treat infections in humans and livestock. Thus, it is important to understand where antimicrobial-resistant E. coli persist and factors that contribute to its their development. Crossbred cattle ( n  = 249; body weight = 244 kg ±25 kg standard deviation) were blocked by arrival date and assigned metaphylactic antimicrobial treatments of sterile saline control, tulathromycin (TUL), ceftiofur, or florfenicol at random. Trimethoprim-sulfamethoxazole (COT R ) and third-generation cephalosporin (CTX R )-resistant E. coli were isolated from fecal samples on days 0, 28, 56, 112, 182, and study END (day 252 for block 1 and day 242 for block 2). Then, susceptibility testing was conducted on all confirmed isolates. MDR was detected in both COT R and CTX R E. coli isolates. In COT R isolates, the number of antimicrobials each isolate was resistant to and the minimum inhibitory concentration (MIC) for amoxicillin-clavulanic acid, ceftriaxone, and gentamicin was greatest on day 28 compared with all other days ( p  ≤ 0.04). Similarly, chloramphenicol MIC was greater on day 28 than on day 0 ( p  < 0.01). Overall, sulfisoxazole MIC was less for TUL than all other treatments ( p  ≤ 0.02), and trimethoprim-sulfamethoxazole MIC was greater for TUL than all other treatments ( p  ≤ 0.03). Finally, there was no effect of treatment, day, or treatment × day for tetracycline or meropenem MIC ( p  ≥ 0.07). In CTX R isolates, there was an effect of day for all antimicrobials tested except ampicillin and meropenem ( p  ≤ 0.06). In conclusion, administering a metaphylactic antimicrobial at feedlot arrival did influence the susceptibility of COT R and CTX R E. coli . However, MDR E. coli are widely distributed, and the MIC for most antimicrobials was not different from the initial value upon completion of the feeding period.

The objective of this study was to characterize descriptive sensory attributes and volatile compounds among ground beef (GB) and plant-based meat alternatives (PBMA). The Beyond Burger, Impossible Burger, a third brand of PBMA, regular GB, and lean GB were collected from local and national chain grocery stores. Patties were formed and cooked on an enamel-lined cast iron skillet to an internal temperature of 71 °C. A trained descriptive sensory panel evaluated patties for 17 flavor attributes and 4 texture attributes. Volatile compounds were extracted using solid phase microextraction and analyzed via gas chromatography-mass spectrometry. Distinct differences in sensory and volatile profiles were elucidated ( p < 0.05). PBMA possessed decreased beef flavor intensity and increased umami, nutty, smokey-charcoal, and musty/earthy flavor compared to GB. Sensory differences corresponded with pyrazine, furan, ketone, alcohol, and aldehyde concentration differences between products. These data support the conclusion that ground beef and PBMA possess different flavor and texture characteristics. Furthermore, the flavor of PBMA varied among available retail brands.

The objective of this study was to evaluate the food safety efficacy of common antimicrobial interventions at and above required uptake levels for processing aids on the reduction of Shiga-toxin producing E. coli (STEC) and Salmonella spp. through spray and dip applications. Beef trim was inoculated with specific isolates of STEC or Salmonella strains. Trim was intervened with peracetic or lactic acid through spray or dip application. Meat rinses were serially diluted and plated following the drop dilution method; an enumerable range of 2-30 colonies was used to report results before log transformation. The combination of all treatments exhibits an average reduction rate of 0.16 LogCFU/g for STEC and Salmonella spp., suggesting that for every 1% increase in uptake there is an increase of 0.16 LogCFU/g of reduction rate. There is a statistical significance in the reduction rate of Shiga-toxin producing Escherichia coli in relation to the uptake percentage ( p < 0.01). The addition of explanatory variables increases the R 2 of the regression for STEC, where all the additional explanatory variables are statistically significant for reduction ( p < 0.01). The addition of explanatory variables increases the R 2 of the regression for Salmonella spp., but only trim type is statistically significant for reduction rate ( p < 0.01). An increase in uptake percentages showed a significant increase in reduction rate of pathogens on beef trimmings.

The objectives of this study were to evaluate the growth rates, carcass quality, shelf-life, tenderness, sensory characteristics, volatile compounds, and fatty acid composition of wool, hair, and composite (wool × hair) lambs. Twenty-one wether lambs [wool (Suffolk × Polypay/Targhee; n = 7), hair (Dorper × Dorper; n = 7), and composite (Dorper × Polypay/Targhee; n = 7)] were fed from weaning to finishing at the University of Idaho Sheep Center and subsequently harvested under United States Department of Agriculture inspection at the University of Idaho Meat Lab. At 48 h postmortem, carcass measurements were taken to determine the percent boneless closely trimmed retail cuts, yield grade, and quality grade. Loins were fabricated from each carcass and wet-aged at 0°C until 10-d postmortem. Following aging, 2.54-cm bone-in loin chops were cut and randomly assigned to 4 d of retail display, Warner-Bratzler Shear Force (WBSF), or sensory analyses. Thiobarbituric acid reactive substances were analyzed on days 0 and 4 of retail display while subjective and objective color measurements were observed once daily. Samples (24 g) were also collected for volatile compound and fatty acid analysis. A mixed model analysis of variance was used to assess breed differences. Discernable effects were considered at P < 0.05. Wool lambs had heavier hot carcass weights (P < 0.001), larger rib-eye area (P = 0.015), and higher dressing percent (P < 0.001) than the other breeds. There was an interaction observed between breed and days of retail display for browning (P = 0.006). On day 1 chops from the composite breed had more browning than chops from the wool breed. No differences were observed between groups for lean muscle L* values (P = 0.432), a* values (P = 0.757), and b* values (P = 0.615). Differences were not observed in lipid oxidation (P = 0.159), WBSF (P = 0.540), or consumer acceptability (P = 0.295). There were differences found for 7 of the 45 fatty acids detected and in 3 of the 67 volatile compounds detected. In conclusion, wool lambs were heavier and had a greater carcass yield than the hair lamb carcasses. Regardless of breed, consumers did not detect sensory traits that would impact their eating experience., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Rapid Evaporative Ionization Mass Spectrometry (REIMS) is a type of ambient ionization mass spectrometry, which enables real-time evaluation of several complex traits from a single measurement. The objective of this study was to evaluate the capability of REIMS analysis of raw samples coupled with chemometrics to accurately identify and predict cooked beef palatability. REIMS analysis and consumer sensory evaluation were conducted for beef arm center roasts (n = 20), top loin steaks (n = 20), top sirloin steaks (n = 20), and 20% lipid ground beef (n = 20). These data were used to train predictive models for six classification sets representing different sensory traits. The maximum prediction accuracies achieved (from high to low): beefy flavor acceptance (86.25%), juiciness acceptance (83.75%), overall acceptance (81.25%), overall flavor acceptance (81.25%), grilled flavor acceptance (78.75%), and tenderness acceptance (75%). The current study demonstrates that REIMS analysis of raw meat has the potential to predict and classify cooked beef palatability., Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05562-6., Competing Interests: Conflict of interestAuthors declare that there is no conflict of interest., (© Association of Food Scientists & Technologists (India) 2022.)

This study assessed how fresh beef tumbling without brine inclusion combined with aging would affect quality, biochemical attributes, and descriptive sensory scores of sirloin muscles. Paired gluteus medius (GM), biceps femoris (BF), and tensor fasciae latae (TFL) muscles from beef carcasses (n = 16) at 5 days postmortem were assigned to 0 or 120 min of tumbling, after which sections were aged 0 or 10 days. Tumbled GM (p < 0.001) and TFL (p < 0.01) muscles had increased objective tenderness compared to respective controls. Greater cook and initial purge losses were induced in all muscles with tumbling (p < 0.05), while thawing loss and purge loss with aging were similar (p > 0.05). Fragmentation of myofibrils was increased with tumbling and aging main effects (p < 0.001), although degradation of troponin T and desmin were primarily affected by aging only. In general, neither tumbling nor aging affected properties of collagen. Trained panelists assessed muscles aged 10 days for descriptive sensory scores including tenderness (myofibrillar, connective tissue, and overall), flavor (beef flavor identity, bloody/serumy, fat-like, liver-like, oxidized, umami, metallic, and sour), and juiciness (overall). Tumbled GM had greater myofibrillar tenderness than the control group (p < 0.05). Most sensory scores were unaffected by tumbling; however, tumbling increased oxidized and liver-like flavors of GM and TFL, respectively, as well as decreased overall juiciness of BF (p < 0.05). These findings indicate tumbling combined with postmortem aging can improve tenderness of certain sirloin muscles like GM, although some impairments to flavor and juiciness could also occur. PRACTICAL APPLICATION: The findings of this study are applicable to the beef industry to develop postharvest strategies to ensure sufficient tenderization of fresh beef sirloin muscles is achieved. However, the effectiveness of this process would differ between individual cuts, and minimizing possible impairments to flavor and juiciness would be critical., (© 2022 Institute of Food Technologists®.)

Aims: Our objective was to determine how injectable antimicrobials affected populations of Salmonella enterica, Escherichia coli and Enterococcus spp. in feedlot cattle., Methods and Results: Two arrival date blocks of high-risk crossbred beef cattle (n = 249; mean BW = 244 kg) were randomly assigned one of four antimicrobial treatments administered on day 0: sterile saline control (CON), tulathromycin (TUL), ceftiofur (CEF) or florfenicol (FLR). Faecal samples were collected on days 0, 28, 56, 112, 182 and study end (day 252 for block 1 and day 242 for block 2). Hide swabs and subiliac lymph nodes were collected the day before and the day of harvest. Samples were cultured for antimicrobial-resistant Salmonella, Escherichia coli and Enterococcus spp. The effect of treatment varied by day across all targeted bacterial populations (p ≤ 0.01) except total E. coli. Total E. coli counts were greatest on days 112, 182 and study end (p ≤ 0.01). Tulathromycin resulted in greater counts and prevalence of Salmonella from faeces than CON at study end (p ≤ 0.01). Tulathromycin and CEF yielded greater Salmonella hide prevalence and greater counts of 128ERY R E. coli at study end than CON (p ≤ 0.01). No faecal Salmonella resistant to tetracyclines or third-generation cephalosporins were detected. Ceftiofur was associated with greater counts of 8ERY R Enterococcus spp. at study end (p ≤ 0.03). By the day before harvest, antimicrobial use did not increase prevalence or counts for all other bacterial populations compared with CON (p ≥ 0.13)., Conclusions: Antimicrobial resistance (AMR) in feedlot cattle is not caused solely by using a metaphylactic antimicrobial on arrival, but more likely a multitude of environmental and management factors., (© 2022 The Authors. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of Society for Applied Microbiology.)

The objective of this study was to characterize and compare the dry-aging flavor precursors and their liberation mechanisms in beef aged with different methods. Thirteen paired loins were collected at 5 days postmortem, divided into four sections, and randomly assigned into four aging methods (wet-aging (WA), conventional dry-aging (DA), dry-aging in a water-permeable bag (DWA), and UV-light dry-aging (UDA)). All sections were aged for 28 days at 2 °C, 65% RH, and a 0.8 m/s airflow before trimming and sample collection for chemical, metabolomics, and microbiome analyses. Higher concentrations of free amino acids and reducing sugars were observed in all dry-aging samples (p < 0.05). Similarly, metabolomics revealed greater short-chain peptides in the dry-aged beef (p < 0.05). The DWA samples had an increase in polyunsaturated free fatty acids (C18:2trans, C18:3n3, C20:2, and C20:5; p < 0.05) along with higher volatile compound concentrations compared to other aging methods (aldehyde, nonanal, octanal, octanol, and carbon disulfide; p < 0.05). Microbiome profiling identified a clear separation in beta diversity between dry and wet aging methods. The Pseudomonas spp. are the most prominent bacterial species in dry-aged meat, potentially contributing to the greater accumulation of flavor precursor concentrations in addition to the dehydration process during the dry-aging. Minor microbial species involvement, such as Bacillus spp., could potentially liberate unique and potent flavor precursors.

The objective of this research was to investigate the influence of maternal prepartum dietary carbohydrate source on growth performance, carcass characteristics, and meat quality of offspring. Angus-based cows were assigned to either a concentrate-based diet or forage-based diet during mid- and late-gestation. A subset of calves was selected for evaluation of progeny performance. Dry matter intake (DMI), body weight (BW), average daily gain (ADG), gain to feed (G:F), and ultrasound measurements (muscle depth, back fat thickness, and intramuscular fat) were assessed during the feeding period. Carcass measurements were recorded, and striploins were collected for Warner-Bratzler shear force (WBSF), trained sensory panel, crude fat determination and fatty acid profile. Maternal dietary treatment did not influence ( p > 0.05) offspring BW, DMI, ultrasound measurements, percent moisture, crude fat, WBSF, or consumer sensory responses. The forage treatment tended to have decreased ( p = 0.06) 12th rib backfat compared to the concentrate treatment and tended to have lower ( p = 0.08) yield grades. The concentrate treatment had increased ( p < 0.05) a * and b * values compared to the forage treatment. These data suggest variation in maternal diets applied in this study during mid- and late-gestation has limited influence on progeny performance.

This study aimed to evaluate the sensory and physical characteristics of zingibain-injected meat combined with sous vide cooking. M. biceps femoris (BF; n = 12) acquired from 6-7 year old Angus cows were cooked using the sous vide method at 65 °C, for 8 h or 12 h, either with ginger powder (GP) injected in a 2 g/L solution in water (treatment) or un-injected (control). The sensory attributes included flavour, juiciness, tenderness, and physicochemical characteristics were Warner-Bratzler shear (WBSF), hardness, total water content (TWC), cooking loss (CL) and collagen content. A significant improvement in tenderness with injection treatment and cooking time was observed, as evaluated through trained sensory panellists, and reduced WBSF and hardness ( p < 0.05 for all). The flavour of the meat was not affected by injection treatment or cooking time ( p > 0.05), but juiciness and TWC were reduced with longer cooking times ( p < 0.01 for both). Soluble collagen increased with injection treatment and cooking time (both p < 0.05). Moderate to high correlations were found between sensory and physical measurements for tenderness and juiciness. The longer cooking time (12 h) with GP injection treatment caused over tenderization of the meat. The soft texture associated with over-tenderization may be suitable for some specialised consumer markets, for instance, the elderly population with chewing difficulties. Improving the eating quality of low-quality meat from old animals through sous vide cooking and the use of ginger proteases may increase the acceptability of lower value beef, potentially enhancing the commercial value of carcasses typically produced in the beef industry.

Plant extracts have been widely used in animal production systems due to the benefits promoted by their bioactive components, mainly through their antioxidant effects and positive effects on animal growth, health, and meat quality. We determined whether bioactive compounds (BC) from grape (Vitis vinifera), olive (Olea europaea), and pomegranate (Punica granatum) have beneficial effects on lamb growth while controlling gastrointestinal parasitism and reducing skeletal lipid peroxidation in muscle. Fourteen lambs (4 to 5 mo of age) were housed in individual pens and assigned to two treatment groups (seven animals/group), where they received: 1) a basal diet of beet pulp:soybean meal (90:10) (CONTROL) and 2) the same diet, but containing 0.3% of BC extracted from grape, olive, and pomegranate (BNP). After 21 d of consuming their respective rations (period 1), all lambs were dosed with 10,000 L3 stage larvae of Haemonchus contortus. Intake, production, and physiological parameters were determined before infection (period 1), after oral dosage with L3 (period 2), and during early (period 3) and later (period 4) developmental stages of infection. Groups of animals did not differ in their ration intake or average daily gain, either before or after the infection, or in their parasitic burdens estimated through fecal egg counts (P > 0.05). Lambs under BNP showed greater feed efficiency before infection (P < 0.001), but the pattern reversed after infection. In addition, the inclusion of plant bioactives to the diet did not have an effect (P > 0.05) on blood or lipid peroxidation in muscle or on hemogram, serum concentration of haptoglobin, and immunoglobulin E. These results could be explained by low dietary doses and constrained absorption or ruminal inactivation of these compounds. Changes in feed efficiencies suggest a negative interaction between BC in the diet and parasitism, which warrants further research., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The present study was conducted to identify flavor-related chemical compounds and to elucidate beef flavor development in response to dry-aging. Paired grass-fed beef loins (n = 18) were obtained at 7 d postmortem, cut into two sections and assigned to 3 aging methods: conventional dry-aging (DA), vacuum packaged wet-aging (WA) and dry-aging in a bag (DW) for 28 days. Following aging, samples were analyzed for UPLC-MS metabolomics, volatile, fatty acid profiling, and consumer sensory comment analysis. Greater number of proteins and nucleotides derived metabolites were liberated in dry-aged samples compared to WA (P < 0.05). In particular, the liberation of gammaglutmayl peptides and glutamine metabolites through the glutathione metabolism were identified. While fatty acid profile was not affected by treatments (P > 0.05), higher concentrations of volatile compounds were found in the dry-aged (P < 0.05). Dry-aging process decreased the presence of terpenoid and steroid lipid group, which could possibly result in reducing undesirable flavor of grass-fed beef., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Our objective was to investigate possible differences in muscle fiber characteristics of beef longissimus lumborum (LL) steaks varying in tenderness (very tender vs. intermediate tender). Therefore, the relative abundance of myosin heavy chain (MHC) isoforms and activity/abundance of several glycolytic and oxidative enzymes were compared between the two steak groups. Greater (P < 0.05) content of MHC type IIa (MHC-IIa) and activities of phosphofructokinase (PFK) and glycogen phosphorylase (GP) were observed in the very tender steaks. Conversely, intermediate tender steaks had greater (P < 0.05) contents of MHC type I (MHC-I) and succinate dehydrogenase (SDH) and greater citrate synthase (CS) activity. Increased tenderness in the very tender steaks was associated with greater (P < 0.05) proteolysis as evaluated by desmin and troponin-T degradation. Further, mitochondrial calcium uniporter (MCU) was lower (P < 0.05) in the very tender steaks than steaks of intermediate tenderness. Collectively, shifting muscle characteristics toward a more glycolytic type appears to positively impact postmortem proteolysis and tenderization., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

To evaluate the effects of a patented Bacillus subtilis probiotic, weaned Holstein steers, not shedding Salmonella ( n  = 40; ∼90 kg), were supplemented (CLO) or not (CON) with CLOSTAT ® (13 g/hd per day; Kemin Industries, Des Moines, IA) in a starter ration for 35 d. The calves were assigned to one of four treatments in a 2 × 2 factorial design with CLO and CON calves that were orally administered Salmonella (STM) or not (NoSTM). Calves were challenged with 1.6 × 10 6 colony-forming unit (CFU) Salmonella Typhimurium (resistant to 50 μg/mL nalidixic acid) in 1 L of milk replacer on day 0. Blood samples were collected through jugular catheters every 6 h for 96 h, and body temperature was measured every 5 min through indwelling rectal temperature recording devices. Five calves from each treatment were harvested 48 h postchallenge, and the remaining calves were harvested 96 h postchallenge. During necropsy, tissues were collected for the isolation and quantification of the inoculated STM from various tissues. The CLOSTM group had reduced STM concentrations in the jejunum, ileum, and transverse colon 48 h after the challenge ( p  ≤ 0.03), but were not different 96 h postchallenge ( p  > 0.05). Decreased ( p  < 0.01) pyrexia was observed after the challenge in CLOSTM calves when compared with CONSTM calves. White blood cells and lymphocyte counts were increased ( p  ≤ 0.05) in CLOSTM calves after the challenge in comparison with other treatments. In calves given STM, the CLO group had greater feed intake before and after the challenge ( p  < 0.01) compared with the CON group. Increased serum IL-6 and IFN-γ concentrations were observed in the CONSTM group compared with other treatments. Overall, CLO reduced Salmonella presence and concentrations in gastrointestinal tissues while simultaneously reducing the severity of the challenge as indicated by blood parameters and the reduced febrile response.

The utility and attractiveness of adipose tissue within meat products vary based on species, cut, and consumer preference. In beef, producers are rewarded for producing carcasses with greater visual marbling at the 12th and 13th rib juncture, while pork producers are either not rewarded or penalized for producing carcasses with too much adipose tissue. Some consumers prefer to purchase leaner meat cuts, while other consumers pay premiums to consume products with elevated fat content. While no clear consumer adipose tissue preference standard exists, advances in beef and swine nutrition have enabled producers to target markets that enable them to maximize profits. One niche market that has increased in popularity over the last decade is manipulating the fatty acid profile, specifically increasing omega-3 fatty acid content, of beef and pork products to increase their appeal in a healthy diet. While much research has documented the ability of preharvest diet to alter the fatty acid profile of beef and pork, the same studies have indicated both the color and palatability of these products were negatively affected if preharvest diets were not managed properly. The following review discusses the biology of adipose tissue and lipid accumulation, altering the omega-3 fatty acid profile of beef and pork, negative fresh meat color and palatability associated with these studies, and strategies to mitigate the negative effects of increased omega-3 fatty acid content., (© The Author(s) 2020. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The objective of this study was to evaluate the influence of metabolizable protein (MP) restriction in mid- and/or late-gestation on meat quality characteristics of progeny. Heifers were assigned to 2 levels of dietary protein (control [CON], 102% of MP requirements; or restricted [RES], 80% of MP requirements) at 2 stages of gestation (mid-gestation [MID] and late-gestation [LATE]) in a Balaam's Design crossover treatment structure resulting in 4 treatment combinations (CON-CON, CON-RES, RES-CON, RES-RES). A carryover effect of MID MP treatment on LATE CON indicated CON-CON steaks were more tender (P < .001) than RES CON. Mid-gestation restriction resulted in progeny with increased (P < .05) carcass water, soft tissue moisture, and decreased soft tissue fat percentage compared with progeny from dams receiving MID CON. Reduced maternal MP also differentially influenced the fatty acid profiles of progeny. Results suggest it is possible for progeny to overcome a moderate gestational MP restriction with minimal impacts on carcass composition or meat characteristics., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The objective of the current study was to determine the effects of three USDA quality grades and cooking on the water-soluble flavor precursors of beef Longissimus lumborum. Raw and cooked steaks from beef strip loins of USDA Prime (PR; n = 8), Low-Choice (LC; n = 8), and Standard (ST; n = 8) were analyzed for extractable free amino acids, reducing sugars, and other nitrogenous organic compounds (NOCs). Overall, two-way quality grade × cooking interactions were found for the contents of most water-soluble precursors (P quality grade × cooking  < 0.05), which were greater in raw LC and ST and were changed more in ST and LC steaks by cooking. The magnitude of those changes suggested that cystine, a dimer of cysteine, glucose, and glucose 6-phosphate might play more important roles in beef flavor development than previously thought., (Published by Elsevier Ltd.)

The objective of this study was to evaluate the effect of dry-aging on meat quality and microbiological properties of grass-fed beef loins. At 7 d postmortem, eighteen bone-in loins (M. longissimus lumborum) from 9 beef carcasses (USDA Select) were obtained. Each loin was cut in half yielding a total of 36 sections, which were assigned to three aging methods: wet-aging (WA); dry-aging (DA); and dry-aging in a water permeable bag (DW). DA resulted in greater shrink and trim loss compared to WA (P < 0.05). However, DW minimized moisture and trim loss resulting in an increase in total saleable yield up to 4%. DA samples were lowest in both aerobic/anaerobic bacteria (P < 0.05). DA steaks had significantly higher flavor and tenderness preferences compared to WA counterparts. Consumers determined DW to have greater juiciness compared with WA (P < 0.05). Our findings indicate that dry-aging could improve eating quality attributes of low marbled grass-fed beef without adversely affecting microbial characteristics., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Plant bioactives can potentially benefit herbivores through their effects on health and nutrition. The objective of this study was to determine the importance of polyphenols and terpenes on the ability of lambs to self-select these compounds when challenged by a parasitic infection and the subsequent impact on their health and productivity. Thirty-five lambs were housed in individual pens and assigned to five treatment groups (7 animals/group), where they received: 1) A basal diet of beet pulp:soybean meal (90:10) (CONTROL); 2) The same diet, but containing 0.3% of bioactive natural plant compounds extracted from grape, olive and pomegranate (BNP); 3) A simultaneous offer of the diets offered to the Control and BNP groups (Choice-Parasitized; CHP-1); 4) The Control diet, and when lambs developed a parasitic infection, the choice described for CHP-1 (CHP-2); and 5) The same choice as CHP-1, but animals did not experience a parasitic burden (Choice-Non-Parasitized; CHNP). Lambs, except CHNP, were dosed with 10,000 L 3 stage larvae of Haemonchus contortus. Infected lambs under choice treatments (CHP-1 and CHP-2) modified their feeding behavior in relation to the CHNP group as they increased their preference for the feed containing polyphenols and terpenes, interpreted as a behavior aimed at increasing the likelihood of encountering medicinal compounds and nutrients in the environment that restore health. This change in behavior corresponded with an improvement in feed conversion efficiency. However, an increased preference for the diet with added plant bioactives did not have an effect on parasitic burdens, hematological parameters, blood oxidation, or serum concentration of IgE., (Copyright © 2018 Elsevier Inc. All rights reserved.)

This study aimed to determine how quality grade and degree of doneness (DOD) influence the development of volatile compounds among beef whole muscle and ground patties. Volatile compounds were quantified via head space solid phase microextraction from samples tempered in refrigerated temperatures (3 to 5 °C), room temperature (24 to 26 °C), or cooked on an electric clamshell-style grill to an endpoint temperature of 55, 60, 71, or 77 °C. Collected samples were subsequently determined by gas chromatography mass spectrometry. Prominent compounds known to be the result of the Maillard reaction or lipid degradation were retained for comparison. Four Strecker aldehydes, 4 pyrazines, and one ester had a 3-way interaction between quality grade, DOD, and product type (each P < 0.001). Pyrazine concentrations did not differ (P > 0.05) in ground patties and was comparably greater (P < 0.05) in steaks; in Prime and Low Choice steaks, pyrazine concentration increased (P < 0.05) as DOD increased. A 2-way interaction between quality grade and product type was observed for acetaldehyde, dimethyl disulfide, 1-penten-3-ol, butanoic acid, hexanal, octanal, nonanal, and 2-heptanone. Among which, octanal and nonanal were greater (P < 0.05) in Prime steaks compared with ground patties. Another 2-way interaction, quality grade and DOD, was observed in 2 ketones, an alcohol, 2 esters, and 2 aldehydes. For example, 2,3-butanedione was greater (P < 0.05) in concentration in Prime 4 °C samples compared with Low Choice and Standard. The final 2-way interaction of DOD and product type was observed in 3 ketones, 2 sulfur compounds, 2 esters, 5 aldehydes, 2 carboxylic acids, and a ketone. For example, 2-heptanone was greater (P < 0.05) in concentration in ground patties compared to steaks in all degrees of doneness except 4 °C. Overall, these results indicate that the volatile flavor profile of beef is greatly influenced by product type and DOD. Generally, consumers select beef based on product type and determine their cookery approach. Therefore, consumers may greatly influence final beef flavor profile.

The objective of this study was to determine the palatability of various beef cuts from 3 USDA quality grades. Five different beef subprimals from USDA Prime, Choice, and Select (n = 10/quality grade) carcasses were utilized for the study, including: strip loins, inside rounds, bottom rounds, shoulder clods, and chuck rolls. Subprimals were fabricated into 9 retail cuts, which contained the following beef muscles: longissimus lumborum (LL); longissimus thoracis, complexus, and spinalis dorsi (LCS); infraspinatus (IF); serratus ventralis (SV); triceps brachii (TB); teres major (TM); adductor (AD); semimembranosus (SM); and biceps femoris (BF). The pH and percentage of fat, moisture, protein, and collagen was determined for each muscle on a raw basis. Additionally, cooked steak measurements included Warner-Bratzler shear force (WBSF) and slice shear force (SSF). Consumer and trained sensory panelists evaluated palatability traits of each cut and quality grade combination. A quality grade × muscle interaction was determined for trained panelists assessment of overall tenderness (P = 0.03), SSF (P = 0.02), proximate composition (P < 0.01), and pH (P < 0.01). In all objective and subjective measurements of tenderness, the LCS was the most tender (P < 0.05), while cuts from the round (BF, AD, and SM) were among the toughest and least juicy (P < 0.05). Conversely, consumers and trained sensory panelists identified the LCS, IF, and SV to be juicier (P < 0.05) than all others. The TB, TM, and LL were perceived by consumers most often as being everyday quality. The LCS was found by consumers to be the most acceptable (P < 0.05) across all attributes, with the SM being the least (P < 0.05) acceptable muscle. For each muscle, fat percentage was the greatest (P < 0.05) in Prime cuts. Slice shear force determined Prime IF, LL, and SV to be more tender (P < 0.05) than Choice and Select. No SSF differences (P > 0.05) were found among quality grades for the AD, BF, and SM. The WBSF values decreased (P < 0.05) across all muscles, as quality grade increased (Prime < Choice < Select). The results of this study indicate that muscles from the chuck may be utilized to provide consumers with a positive eating experience. Meanwhile, muscles from the round are likely to provide consumers with a lower quality eating experience.

This study aimed to determine the influence of finishing diet on beef appearance and lipid oxidation of three beef muscles. A total of 18 Angus steers were selected from three diet treatments: grass-finished (USUGrass), legume-finished (USUBFT), and grain-finished (USUGrain). After processing, longissimus thoracis (LT), triceps brachii (TB), and gluteus medius (GM) steaks were evaluated over a 7-d display period. A muscle × diet interaction was observed for instrumental lightness (L*) and redness (a*) (P ≤ 0.001). Within each combination, USUGrass was considered darker with lower (P < 0.05) L* compared with USUGrain. For USUBFT, L* was similar to USUGrain for the TB and LT, while the L* of USUBFT and USUGrain GM differed (P < 0.05). In terms of redness, LT a* values were elevated (P < 0.05) in USUGrass compared with USUBFT and USUGrain. For GM steaks, a* of USUBFT and USUGrass were each greater (P < 0.05) than USUGrain. Surface a* of TB steaks were greatest (P < 0.05) for USUGrass followed by USUBFT, and with USUGrain, being lowest (P < 0.05). An overall increase in L* was observed throughout display dependent on diet (P = 0.013). During display, USUGrain steaks had the greatest (P < 0.05) L* followed by USUBFT and USUGrass. Additionally, a day × muscle interaction was observed for a* (P = 0.009). Initially, TB steaks had the greatest (P < 0.05) a* values. However, at day 3, a* values were similar (P > 0.05) among muscles. Visual color scores were in agreement with loss of redness (a*) during display, dependent on diet and muscle type (P < 0.001). Similarly, a day × diet × muscle interaction was observed for visual discoloration (P < 0.001). Day and diet interacted to influence thiobarbituric acid reactive substances (TBARS) (P < 0.001). Initial values did not differ (P > 0.05) between USUGrain and USUBFT; however, USUGrass had lower initial (P < 0.05) TBARS than both USUGrain and USUBFT. At days 3 and 7, TBARS were greatest (P < 0.05) in USUGrain steaks, followed by USUBFT, which was greater (P < 0.05) than USUGrass. A diet × muscle interaction was observed for 10 volatile compounds originating from lipid degradation (P ≤ 0.013). These compounds were less (P < 0.05) abundant in USUGrass compared to TB or GM of USUGrain. This study determined grass-finished beef to have a darker more red color and less lipid oxidation in multiple muscles. Possible mechanisms for this may include an increase in endogenous antioxidants in grass-finished beef.

The objectives of this study were to evaluate the contribution of tenderness, juiciness, and flavor to the overall consumer beef eating experience and to evaluate the risk of overall palatability failure due to the unacceptable level of one or more of these traits. Data from 11 previously conducted studies representing a wide range of treatments and levels of eating quality that included more than 1,500 beef samples and 1,800 consumers were compiled and analyzed for this study. Results of a multivariate regression indicated that tenderness, flavor, and juiciness accounted for 43.4%, 49.4%, and 7.4%, respectively, of overall palatability ( P < 0.05; R 2 > 0.99). Additionally, the odds of a steak being rated unacceptable overall when tenderness, juiciness, or flavor were rated unacceptable were 2.2 to 1 (69%), 1.9 to 1 (66%), and 3.3 to 1 (77%), respectively. This indicated overall palatability was 7.2, 6.5, and 12.3 times more likely to be rated unacceptable if tenderness, juiciness, or flavor, respectively, was also rated unacceptable. Additionally, the percentage of samples rated acceptable for each palatability trait increased ( P < 0.05) as quality grade increased. More than 88% of USDA Prime samples were rated acceptable for each palatability trait, whereas only 74.8-77.3% of USDA Select samples were rated acceptable for each palatability trait. Marbling score accounted for 14-16% of the variation ( P < 0.01) in consumer palatability scores for each trait and intramuscular fat percentage accounted for 17-21% of the variation in each trait ( P < 0.01). Logistic equation models for the predicted probability of an acceptable rating for each palatability trait based on intramuscular fat percentage accounted for only a minimal amount of variation ( P < 0.01; R 2 ≤ 0.09). Results of this study indicate the relative contribution of tenderness, juiciness, and flavor to overall beef palatability. They provide evidence that the failure of even a single palatability trait dramatically increases the likelihood of overall palatability failure, indicating that no single palatability trait is most important, as beef palatability is dependent upon the acceptance of all three traits: tenderness, juiciness, and flavor., (© The Author(s) 2018. Published by Oxford University Press on behalf of American Society of Animal Science.)

The objective of this study was to evaluate multiple instrumental measures of beef juiciness and determine their relationships with sensory panel juiciness ratings. Treatments were selected to maximize variation in juiciness and included 5 USDA quality grades (Prime, upper two-thirds Choice, lower one-third Choice, Select, and Standard) as well as 2 enhanced Select treatments (112 and 107% of the initial raw weight) and were prepared to 3 degrees of doneness (DOD; rare [66°C], medium [71°C], and well done [77°C]). A total of 21 objective measures of raw samples were evaluated and included marbling level, CIE color values, pH, water activity, proximate composition, and multiple measures of water-holding capacity. Also, 17 objective measures were evaluated for cooked beef samples and included cooking loss, drip loss, and compression-based methods used to quantify expressible moisture. These measures were compared with results from a previous sensory study to evaluate the relationship between the various objective measures and sensory panel juiciness ratings. Differences ( < 0.05) were found among quality treatments for many of the measures evaluated, with the greatest differences occurring for many of the measures among samples cooked to different DOD. Of all the objective measures evaluated, protein percentage, cooking loss, and pressed juice percentage (PJP) were most closely associated ( < 0.05) with consumer juiciness ratings ( = -0.55, = -0.51, and = 0.45, respectively). Additionally, cooking loss and PJP were more closely associated ( < 0.05) with trained sensory panel initial and sustained juiciness ratings than all other measures evaluated. Regression analysis revealed that PJP explained ( < 0.05) 20, 48, and 45% of the variation in consumer, trained panel initial, and trained panel sustained juiciness scores, respectively. This was a greater percentage of the variation than slice shear force explained ( < 0.05) in trained sensory panel initial (39%) and sustained tenderness ratings (40%) and similar to the amount explained (26%) in consumer tenderness ratings. These results indicate PJP was a better predictor of sensory panel juiciness scores than all traits evaluated other than the cooking loss of steaks evaluated by sensory panelists. Pressed juice percentage explained a similar or greater amount of variation in sensory panel scores as slice shear force, indicating PJP as a potential industry standard for objective juiciness evaluation.

The objective of this study was to assess the impact of cattle finishing diet and muscle type on meat quality. Consumer sensory response, proximate composition, Warner-Bratzler shear force (WBSF), fatty acid composition, and volatile compounds were assessed from the gluteus medius (GM) and triceps brachii (TB) muscles of cattle ( = 6 per diet) which were grain-finished (USUGrain) on conventional feedlot or 2 forage diets, a perennial legume, birdsfoot trefoil-finished (USUBFT; ), and grass-finished (USUGrass; ). Diet had an interacting effect with muscle for all sensory attributes ( ≤ 0.002), except aroma and flavor ( ≥ 0.078). In forage-finished beef, tenderness, fattiness, overall liking, and WBSF tenderness of GM was greater ( < 0.05) than TB, whereas for USUGrain, the tenderness, fattiness, overall liking, and WBSF tenderness of both muscles were similar ( > 0.05) but the juiciness of TB was more liked than USUGrain GM ( < 0.05). The juiciness of forage-finished beef did not differ ( > 0.05) between GM and TB. Lower ( < 0.05) intramuscular fat (IMF) percent was determined for USUGrass beef in comparison with USUGrain beef. The IMF percent of USUBFT beef was similar ( > 0.05) to both USUGrass and USUGrain beef. However, IMF percent was not impacted by muscle type ( = 0.092). The ratio of -6:-3 fatty acids was affected by muscle dependent on diet ( = 0.016). The ratio of -6:-3 fatty acids was affected by the interaction of muscle × diet ( = 0.016). Between forage diets (USUGrass and USUBFT), -6:-3 ratios were similar ( > 0.05) between GM and TB, whereas within USUGrain, the GM was greater ( < 0.05) than the TB. Cumulative MUFA was greater ( < 0.05) in USUGrain compared with both USUGrass and USUBFT, which were similar ( > 0.05). Strecker aldehydes, ketones, pyrazines, and methional were affected ( ≤ 0.036) by muscle and found to have a greater concentration in GM compared with TB. Overall, consumers determined that USUGrain GM and TB had similar ( > 0.05) quality ratings. However, within forage-finished beef, the GM was perceived more frequently ( < 0.05) to be of premium quality and the forage-finished TB was more frequently ( < 0.05) rated as having unsatisfactory quality. These findings were in agreement with ratings of tenderness and overall liking. Therefore, in the context of our consumer group grilled GM and TB steaks, grain-finished beef provided more uniform quality and eating experience compared with forage-finished beef.

The palatability of USDA graded beef strip loins of seven treatments [High Enhanced (HE: 112% of raw weight) Select, Low Enhanced (LE: 107% of raw weight) Select, Prime, upper 2/3 Choice (Top Choice), lower 1/3 Choice (Low Choice), Select, and Standard] cooked to three degrees of doneness [DOD; rare (60°C), medium (71°C), or well-done (77°C)] was evaluated by consumer and trained sensory panelists. For consumers, Select HE steaks rated higher (P<0.05) for juiciness, tenderness, flavor identity, flavor liking, and overall liking than all non-enhanced treatments other than Prime. No differences (P>0.05) were observed between Select LE and Prime samples for most traits evaluated. The effect of USDA grade and enhancement on trained panel palatability scores was independent of DOD for all traits other than juiciness, with the role of marbling in juiciness increasing as DOD increased from rare to well-done. These results indicate enhancement as an effective method to improve the palatability of lower grading beef., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Providing cattle a more bioavailable zinc (Zn) source prior to administering a beta adrenergic agonist (βAA) may enhance the metabolic pool of primary nutrients that will influence the magnitude of the βAA response. Calf-fed Holstein steers were supplemented with a Zn methionine supplement (ZnMet; ZINPRO(®); Zinpro Corporation, Eden Prairie, MN) for 115 ± 5 days prior to harvest along with zilpaterol hydrochloride (ZH; Zilmax(®); Merck Animal Health, Summit, NJ) for the last 20 days with a 3-day withdrawal to evaluate the effects on growth and carcass performance together with gene and protein expression of skeletal muscle, adipose tissue, and fatty acid composition of polar and neutral lipid depots. Steers (n = 1296; initial weight = 468.5 ± 0.5 kg) were sorted by weight, blocked by harvest date, and randomly assigned to pens (n = 12) and treatments: control (90 ppm Zn from ZnSO4) and ZnMet (Control plus 720 mg Zn from ZnMet/hd/d). There were no differences (P > 0.05) in growth performance or carcass characteristics. The ZnMet-fed cattle had reduced (P < 0.05) abundance of myosin heavy chain (MHC)-IIX, β1-adrenergic receptor (βAR), peroxisome proliferator-activated receptor gamma, and stearoyl-CoA desaturase mRNA in skeletal muscle tissue. The ZnMet cattle had greater (P < 0.05) abundance of MHC-II protein, increased MHC-IIA and IIX cross-sectional areas (P < 0.05), an increased percentage of MHC-I fibers (P < 0.05), and a decreased percentage of MHC-IIX fibers (P < 0.05). The combination of ZnMet and ZH had positive biological effects on musculoskeletal tissue; however, these molecular effects were not significant enough to impact overall feedlot and carcass performance.

Fatty acids (FA) in neutral and polar lipids (NL and PL) and volatile compounds were determined in Gluteus medius (GM), Longissimus lumborum (LL), Serratus ventralis (SV), and Semimembranosus (SM) muscles from upper 2/3 USDA Choice and Select quality grades (QG). Concentrations of NL FA (mg/g) were influenced by intramuscular fat (IMF) content being greater in upper 2/3 Choice compared with Select. The SV contained greater concentrations of NL FA; meanwhile, the SM contained the lowest quantities of NL FA. Percentages (g/100g of total FA) of NL SFA and MUFA were increased in beef with greater IMF content. Concentrations and percentages of PL FA had muscle specific differences between QG. Volatile compounds were primarily affected by muscle. Increases in SFA and MUFA were related with consumer liking, regardless of lipid fraction. Overall the influence of QG on SFA and MUFA was muscle specific. Therefore, each muscle may require specific considerations when considering FA, volatile compounds, and ultimately consumer liking., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Consumer liking, proximate composition, pH, Warner-Bratzler shear force, fatty acid composition, and volatile compounds were determined from the LM (longissimus thoracis) of cattle ( = 6 per diet) finished on conventional feedlot (USUGrain), legume, and grass forage diets. Forage diets included a condensed tannin-containing perennial legume, birdsfoot trefoil (; USUBFT), and a grass, meadow brome ( Rehmann; USUGrass). Moreover, representative retail forage (USDA Certified Organic Grass-fed [OrgGrass]) and conventional beef (USDA Choice, Grain-fed; ChGrain) were investigated ( = 6 per retail type). The ChGrain had the greatest ( < 0.05) intramuscular fat (IMF) percentage followed by USUGrain, the IMF percentage of which was greater ( < 0.05) than that of USUGrass and OrgGrass. The IMF content of USUBFT was similar ( > 0.05) to that of both USUGrain and USUGrass. Both grain-finished beef treatments were rated greater ( < 0.05) for flavor, tenderness, fattiness, juiciness, and overall liking compared with USUGrass and OrgGrass. Consumer liking of USUBFT beef tenderness, fattiness, and overall liking were comparable ( > 0.05) with that of USUGrain and ChGrain. Flavor liking was rated greatest ( < 0.05) for USUGrain and ChGrain, and that of USUBFT was intermediate ( > 0.05) to those of ChGrain, USUGrass, and OrgGrass. Cumulative SFA and MUFA concentrations were greatest ( < 0.05) in ChGrain and USUGrain, whereas USUGrass and OrgGrass had lower ( < 0.05) concentrations. Concentrations of cumulative SFA and MUFA in USUBFT were intermediate and similar ( > 0.05) to those of USUGrain and USUGrass. Each forage-finished beef treatment, USUGrass, OrgGrass, and USUBFT, had lower ( < 0.001) ratios of -6:-3 fatty acids. Hexanal was the most numerically abundant volatile compound. The concentration of hexanal increased with increasing concentrations of total PUFA. Among all the lipid degradation products (aldehydes, alcohols, furans, carboxylic acids, and ketones) measured in this study, there was an overall trend toward greater quantities in grain-finished products, lower quantities in USUGrass and OrgGrass, and intermediate quantities in USUBFT. This trend was in agreement with IMF content, fatty acid concentrations, and sensory attributes. These results suggest an opportunity for a birdsfoot trefoil finishing program, which results in beef comparable in sensory quality with grain-finished beef but with reduced -6 and SFA, similar to grass-finished beef.

Sensory analysis of ground LL samples representing 12 beef product categories was conducted in 3 different regions of the U.S. to identify flavor preferences of beef consumers. Treatments characterized production-related flavor differences associated with USDA grade, cattle type, finishing diet, growth enhancement, and postmortem aging method. Consumers (N=307) rated cooked samples for 12 flavors and overall flavor desirability. Samples were analyzed to determine fatty acid content. Volatile compounds produced by cooking were extracted and quantified. Overall, consumers preferred beef that rated high for beefy/brothy, buttery/beef fat, and sweet flavors and disliked beef with fishy, livery, gamey, and sour flavors. Flavor attributes of samples higher in intramuscular fat with greater amounts of monounsaturated fatty acids and lesser proportions of saturated, odd-chain, omega-3, and trans fatty acids were preferred by consumers. Of the volatiles identified, diacetyl and acetoin were most closely correlated with desirable ratings for overall flavor and dimethyl sulfide was associated with an undesirable sour flavor., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Consumer palatability scores, sensory descriptive attributes, and volatile compounds were assessed for beef Longissimus lumborum steaks of USDA Prime, Low Choice, and Standard grades. Overall and flavor liking was greater (P<0.05) for Prime and Low Choice. Initial flavor impact and fat-like attributes were greater (P<0.05) among Prime and Low Choice. Prime had greater (P<0.05) brown/roasted, beef identity, overall sweetness, and umami. Cardboard was greater (P<0.05) in Standard. Volatile compounds representing flavor development pathways were varied with quality grade. Standard had greater (P<0.05) abundances of n-aldehydes. Phenylacetaldehyde was greater (P<0.05) in Prime and Low Choice. Both 2,3-butanedione and 3-hydroxy-2-butanone were greatest (P<0.05) in Prime. Overall liking was positively correlated with many descriptive attributes, 3-hydroxy-2-butanone, and phenylacetaldehyde, and negatively correlated with cardboard, green, and n-aldehydes. While the measured attributes and volatiles may not be causative of flavor, this data indicates potential for prediction of flavor through their measurement., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The effects of USDA beef quality grade (QG; Prime, Low Choice, and Standard; n=8) and cooking (RC) on fatty acid (FA) concentrations (mg/g dry matter) and percentages of neutral and polar lipid fractions (NL and PL, respectively)from strip steaks were explored. An increase in QG led to an accumulation of most FA, especially in the NL fraction (P < 0.001). Common effects on FA percentages were two-way interactions of either QG or RC with LF (P ≤ 0.019). Fatty acids were affected differently by QG and RC depending on their originating LF. Monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) percentages of the PL were dependent on QG (P ≤ 0.014). Cooking and QG had minimal impact on FA percentages of the NL, however, greatly influenced PL MUFA and PUFA percentages (P b 0.001). There was evidence indicating that dry heat cookery affected not only PUFA, as generally thought, but also the MUFA of PL fraction.

Proximate data, consumer palatability scores and volatile compounds were investigated for four beef muscles (Longissimus lumborum, Psoas major, Semimembranosus and Gluteus medius) and five USDA quality grades(Prime, Upper 2/3 Choice, Low Choice, Select, and Standard). Quality grade did not directly affect consumer scores or volatiles but interactions (P < 0.05) between muscle and grade were determined. Consumer scores and volatiles differed (P < 0.05) between muscles. Consumers scored Psoas major highest for tenderness, juiciness, flavor liking and overall liking, followed by Longissimus lumborum, Gluteus medius, and Semimembranosus (P < 0.05). Principal component analysis revealed clustering of compound classes, formed by related mechanisms. Volatile n-aldehydes were inversely related to percent fat. Increases in lipid oxidation compounds were associated with Gluteus medius and Semimembranosus, while greater quantities of sulfur-containing compounds were associated with Psoas major. Relationships between palatability scores and volatile compound classes suggest that differences in the pattern of volatile compounds may play a valuable role in explaining consumer liking.

The palatability of tender [Warner-Bratzler shear force values <33.34N (3.4kg)] beef strip loins of 10 different treatments [USDA Prime, High Choice (upper 1/3 Choice), Low Choice (lower 1/3 Choice), Select, Standard, Australian Wagyu, American Wagyu, Holstein Select, Holstein Top Choice (upper 2/3 Choice) and Grass-finished] was evaluated by consumers and a trained flavor panel. In general, tenderness, juiciness, flavor, and overall liking ratings as well as acceptability percentage for each trait, increased with increased fat levels. Moreover, overall liking was highly correlated (P<0.01) with flavor liking (r=0.96) as well as fat percentage (r=0.79). Beef flavor scores were positively associated (P<0.01) with fat-like (r=0.67) and umami (r=0.59) flavors. Fat level was the primary driver of beef flavor acceptability in all samples when no undesirable off-flavors were present., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Consumer sensory analysis was conducted to determine differences in beef palatability between two quality grade categories [Upper 2/3 (Top) Choice and Select] and four muscles [longissimus lumborum (LL), gluteus medius (GM), serratus ventralis (SV), and semimembranosus (SM)]. Generally, tenderness, flavor, and overall liking scores were more desirable for Top Choice compared to Select, regardless of muscle. Consumers rated LL as more tender (P<0.05) than SV and SM, but similar to GM (P=0.52). Overall and flavor acceptability were similar (P>0.05) between LL, GM, and SV, regardless of quality grade. Consumer overall liking was most highly correlated with flavor liking (r=0.85). When tenderness was acceptable, flavor and juiciness played a major role in determining overall acceptability. Overall liking of GM and SV from Top Choice carcasses was superior to LL from Select carcasses and comparable to LL from Top Choice carcasses., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The effect of storage length and temperature on the shelf life of three ground beef formulations (lean:fat: 73:27, 81:19 and 91:9) was investigated. Coarsely ground beef was stored at -1.7 or 2.3°C for up to 28d. Traditional overwrap packages were produced every 7d prior to retail display for 24h. Lipid oxidation (TBARS), subjective color, instrumental color, and aerobic bacteria were evaluated after 0 and 24h of display. Formulation influenced initial L* and subjective color values (P<0.05). Storage temperature did not affect initial color, but product stored at 2.3°C was more discolored after 24h (P<0.05). Aerobic bacteria increased as storage d and temperature increased (P<0.05). Initial TBARS increased through d 21, but were lower after 28d. Overall, initial characteristics depended on formulation; however, ground beef shelf-life and stability were largely influenced by storage length and storage temperature., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Beef nutrition is important to the worldwide beef industry. The objective of this study was to analyze proximate composition of eight beef rib and plate cuts to update the USDA National Nutrient Database for Standard Reference (SR). Furthermore, this study aimed to determine the influence of USDA Quality Grade on the separable components and proximate composition of the examined retail cuts. Carcasses (n=72) representing a composite of Yield Grade, Quality Grade, gender and genetic type were identified from six regions across the U.S. Beef plates and ribs (IMPS #109 and 121C and D) were collected from the selected carcasses and shipped to three university meat laboratories for storage, retail fabrication, cooking, and dissection and analysis of proximate composition. These data provide updated information regarding the nutrient content of beef and emphasize the influence of common classification systems (Yield Grade and Quality Grade) on the separable components, cooking yield, and proximate composition of retail beef cuts., (Copyright © 2013 Elsevier Ltd. All rights reserved.)