Introduction
The environmental impact of livestock production is a concern of consumers, and therefore, the beef industry (Liu et al., 2023). There is evidence from the National Emissions Inventory Program that indicates livestock production accounts for 59% of total agricultural ammonia emissions into the atmosphere (EPA, 2023). Therefore, attention to the development of new technologies to decrease the environmental impact of livestock production has increased significantly.
Beta-agonists (β-A) have been used for decades for increased rate of weight gain, improved feed efficiency, and increased carcass leanness in beef cattle. The FDA has approved 3 molecules for use in beef cattle: ractopamine hydrochloride (RH; FDA, 2003), zilpaterol hydrochloride (ZH; FDA, 2006), and lubabegron fumarate (LUB; FDA, 2018; Experior®, Elanco Animal Health, Indianapolis, IN). Both RH and ZH were approved for the increase in carcass yield, average daily gain, and improved feed efficiency (FDA, 2003, 2006). However, LUB was approved for the decrease of NH3 emissions per unit live weight and carcass weight (FDA, 2018).
The LUB compound functions differently from RH and ZH. It is classified as a “beta-adrenergic agonist/antagonist” (FDA, 2018), as it has antagonistic properties at the β1 and β2 receptor subtypes and agonistic properties at the β3 receptor subtype (Dilger et al., 2021). Previously approved β-A RH and ZH behave oppositely, with agonistic properties at β1 and β2 receptor subtypes only. Moreover, LUB selectively binds to β-adrenergic receptors, with low affinity for binding to non-β-adrenergic receptors, making it a selective β-agonist/antagonist, more accurately referred to as a β-modulator, rather than a β-A (Dilger et al., 2021).
The decrease of total ammonia emissions per unit of body weight by LUB is accounted for by both a decrease in total NH3 emissions and increased final body weight (Teeter et al., 2021; Vogel et al., 2023). Moreover, Kube et al. (2021), Teeter et al. (2021), and Vogel et al. (2023) reported that LUB had a positive effect on dressing percentage, hot carcass weight, and ribeye area, while not affecting mobility score. The decrease in NH3 emissions and increase in yield by LUB does not come without affecting carcass quality. Previous research has shown that cattle fed ZH and RH result in a decrease in tenderness (Garmyn et al., 2010; Arp et al., 2013; Martin et al., 2014). Moreover, LUB has been shown to decrease marbling score and increase Warner-Bratzler Shear force compared to cattle not fed a β-A (FDA, 2018; Kube et al., 2021). Previous literature evaluating meat quality has thoroughly investigated RH and ZH; however, LUB has been less thoroughly investigated. Wendler et al. (2025) and Corona et al (2025) resulted in increasing shear force values of striploin steaks from LUB-fed steers, paired with decreases in tenderness and juiciness (Corona et al., 2025). Therefore, the objective of this study was to evaluate the effect of lubabegron in beef heifers on steak dimensionality, shear force, and trained sensory analysis of beef strip loin steaks.
Materials and Methods
Sample collection & processing
Continental and British type heifers were sourced from a LUB dose and duration study in the Pacific Northwest investigating the effects of LUB on performance and ammonia gas emissions. Feeding and treatment methodologies are presented briefly here. Heifers were screened for eligibility, then stratified by initial weight and breed type before assignment to treatments in a randomized complete block design. Data utilized in the present study were derived from a single cycle of the larger 5-cycle experiment, with the single cycle consisting of 438 heifers housed in soil-surfaced pens with ad libitum access to feed and water. Treatments followed a 4 × 3 factorial arrangement evaluating 4 doses of lubabegron (0, 1.5, 3.5, or 5.5 mg/kg dry matter) across 3 feeding durations (28, 56, or 84 d before harvest). Feed intake was monitored daily, and diet composition and LUB concentrations were verified through routine sampling and laboratory analysis to ensure treatment accuracy and consistency. Lubabegron treatment was ceased 4 d before harvest for withdrawal.
Over 2 separate days, heifers were harvested and chilled for 24 h in a commercial processing facility. USDA Choice strip loins (Small00 to Moderate100, IMPS # 180, North American Meat Institute, 2014) were collected from the LUB (n = 54) and the control (CON) (n = 52) carcasses. Treated animals were sourced only from heifers fed LUB for 56 d before harvest at a dose of 3.5 mg per kg of dry matter intake. Subprimals were vacuum packaged, boxed, and shipped via commercial reefer truck under refrigerated conditions to the Gordon W. Davis Meat Laboratory at Texas Tech University, Lubbock, TX., and stored at 0 to 4°C until fabrication.
At 7 d postmortem, loins were fabricated into 2.54-cm steaks and measured for dimensionality as described by Foraker et al. (2022). In short, steaks were assigned an identification number, with 1 representing the most anterior steak, and 11 representing the most posterior steak. Steaks were pictured using a DSLR camera (Model D7100, Nikon Corp., Thailand) with a fixed-zoom lens (Model DXSWMVREDIF, Nikon Corp., Thailand), with a ruler placed approximately 2.54 cm above the steak. Steaks were measured in duplicate from the medial to lateral end for width at 25%, 50%, 75%, and 87.5% using Image J (version 2.0.0, National Institute of Health, Bethesda, MD). Measurement locations for dimensionality are illustrated in Figure 1. When the gluteus medius was present, in the more posterior steaks, only the longissimus dorsi was utilized for measurement. Following picturing, steaks were assigned an aging period: 7, 14, 21, 28, or 35 d, and specific assay: trained sensory analysis, slice shear force (SSF). Steaks were individually vacuum packaged (MULTIVAC, F 100, Multivac Inc., Kansas City, MO, USA) with 422 mm × 609 m transparent forming web (forming film; T6035B, CRYOVAV, Sealed Air Corporation, Charlotte, NC, USA). Steaks were aged in the dark at 0°C to 4°C for their prescribed aging period, then frozen and stored at −20°C.
Dimension criteria for steak dimensionality measurements.
Cooking procedure
Steaks designated for trained sensory analysis and SSF were thawed for 24 to 48 h at 2°C to attain an internal temperature of 0 to 4°C at the time of cooking. Steaks were cooked in a protocol similar to Frink (2021). In short, steaks were cooked at 204°C, 0% relative humidity, at default fan speed in a combi-oven (Model SCC WE 61 E; Rational, Landberg am Lech, Germany) on a grill grate (Rational 60.73.314; Rational, Landberg am Lech, Germany). Internal temperature monitored throughout the cooking process using a temperature probe (Rational 40.04.506; Rational, Landberg am Lech, Germany). Steaks were cooked to a peak internal temperature of 71°C, using a calibrated, type K thermocouple thermometer (AccuTuff 340, model 34040, Cooper-Atkins Corporation, Middlefield, CT, USA) placed in the geometric center of each steak.
Trained sensory analysis
Sensory panelists were trained for approximately 20 h to objectively identify flavor intensities according to the Research Guidelines for Cookery, Sensory Evaluation, and Instrumental Tenderness Measurements of Meat (Miller et al. 2026). Each panel consisted of 6 panelists evaluating 12 samples, equally representing LUB and CON steaks aged 14 and 28 d. Descriptive trained sensory analysis was conducted with methods and procedures outlined in Foraker et al. (2022). Briefly, cooked steaks were trimmed of subcutaneous fat and connective tissue, cut into 1-cm cubes, and immediately served to panelists in individual cubicles under red incandescent lighting. Attributes outlined in Table 1 were rated on a 100-point scale, with 0 = extremely dry/tough/not detectable and 100 = extremely juicy/tender/intense. Panelist responses were recorded on an electronic ballot generated by an online survey software (Version 2417833; Qualtrics Software, Provo, UT, USA), on electronic tablets (iPad, Apple Inc., Cupertino, CA, USA), and ratings for each sample were averaged among panelists.
Definitions and references for beef flavor attributes and intensities1
| Attribute | Definition |
|---|---|
| Beef flavor | Amount of beef flavor identity in the sample: Swanson’s beef broth |
| Fat-like | Aromatics associated with cooked animal fat: Hillshire Farms Lit’l Beef Smokies |
| Brown | A round, full aromatic generally associated with beef suet that has been broiled, caramelized: broiled beef suet |
| Roasted | Flavor associated with beef that has been roasted: broiled beef suet |
| Metallic | The impression of slightly oxidized metal, such as iron, copper, and silver spoons: Dole canned pineapple juice |
| Oxidized | Aromatic associated with oxidized fat and oils. These aromatics may include cardboard, painty, varnish, and fishy: microwaved vegetable oil |
| Liver-like | Aromatics associated with cooked organ meat/liver: beef liver |
| Sour | Fundamental taste factor associated with citric acid: 0.050% citric acid solution |
| Umami | Flat, salty, somewhat brothy; taste of glutamate, salts of amino acids, and other molecules called nucleotides: 0.035% accent flavor enhancer solution |
Adapted from Adhikari et al. (2011) and Foraker et al. (2022).
Slice shear force
Steaks were grouped by similar weight, size, and shape and thawed and cooked according to the procedures previously outlined. The raw internal temperature was recorded before cooking, and the peak temperature was recorded post-cooking (AccuTuff 340, model 34040, Cooper-Atkins Corporation, Middlefield, CT, USA). Slice shear force measurements were obtained from each strip loin, and each aging period within each strip loin, using procedures described in Shackelford et al. (1999). In brief, immediately after recording peak temperature, one cut was made 2 cm from the lateral end, followed by another slice 5 cm from the original cut. The slice was sheared perpendicular to the muscle fibers using a slice shear force machine (Model GR-152, Tallgrass Solutions, Inc., Manhattan, KS, USA), and peak force was recorded.
Statistical analysis
All data were analyzed using R statistical software version 1.4.1717 (RStudio, PBC) with a significance level of α = 0.05 for all analyses. Data were analyzed as a split plot, with LUB treatment serving as the main plot factor, and aging period as the subplot factor. An analysis of variance was computed for trained sensory analysis, SSF, and steak dimensionality. The aging period, LUB treatment, and their interactions served as fixed effects for SSF and sensory analysis. The LUB treatment and steak position served as the fixed effect for steak dimensionality analysis. However, given that the interaction of LUB treatment and steak position was not statistically significant for any attribute, and the interest in how LUB changes muscle deposition across the loin, LUB treatment was tested at each steak location. In order to decrease the chance of comparison-wise error rate, a stringent Bonferroni adjustment was utilized. Peak temperature was included as a covariate to account for variation caused by differences in peak temperature in trained sensory and SSF analyses when significant, and shear day was included as a random effect for SSF.
Results
Steak dimensionality
Estimated marginal means of dimensionality measurements for steak length and steak area are summarized in Table 2. In terms of steak length from medial to lateral end, LUB steaks measured longer than CON steaks at locations 2, 3, and 4 (P = 0.02), while there were no differences among treatments at all other locations (P > 0.10). Conversely, LUB steaks had a larger surface area than CON steaks at 7 of the 11 steak locations across the loin (P ≤ 0.05), excluding the 2 most anterior locations, the most posterior location, and steak location 7, which were not different (P ≥ 0.07).
Estimated marginal means of USDA Choice strip steak length (cm) and steak area (cm2) aged for 7 d from lubabegron (LUB) or control heifers (no LUB)
| Length | Area | |||||||
|---|---|---|---|---|---|---|---|---|
| Steak Number1 | Control | LUB2 | SEM3 | P Value | Control | LUB | SEM | P Value |
| 1 | 14.3 | 14.5 | 0.13 | 0.34 | 87.0 | 89.1 | 1.37 | 0.27 |
| 2 | 13.5 | 14.0 | 0.13 | 0.02 | 83.3 | 86.3 | 1.48 | 0.16 |
| 3 | 13.0 | 13.5 | 0.15 | 0.02 | 80.7 | 85.2 | 1.27 | 0.01 |
| 4 | 13.1 | 13.4 | 0.11 | 0.04 | 79.5 | 83.8 | 1.21 | 0.01 |
| 5 | 13.3 | 13.5 | 0.17 | 0.41 | 76.9 | 80.5 | 1.35 | 0.05 |
| 6 | 13.7 | 13.9 | 0.14 | 0.23 | 75.3 | 78.7 | 1.33 | 0.07 |
| 7 | 14.3 | 14.5 | 0.20 | 0.60 | 75.1 | 79.2 | 1.35 | 0.03 |
| 8 | 15.4 | 15.9 | 0.20 | 0.10 | 77.1 | 81.6 | 1.41 | 0.03 |
| 9 | 16.4 | 16.5 | 0.22 | 0.76 | 79.5 | 83.7 | 1.51 | 0.05 |
| 10 | 17.3 | 17.6 | 0.19 | 0.29 | 80.0 | 84.0 | 1.24 | 0.02 |
| 11 | 18.3 | 18.2 | 0.19 | 0.75 | 81.2 | 83.0 | 1.31 | 0.33 |
Steaks were numbered beginning at the anterior end, with 1 being the most anterior steak and 11 being the most posterior.
Lubabegron fed for 56 d before harvest.
Standard error measure (largest) of the estimated marginal means.
Estimated marginal means of steak width measurements are summarized in Table 3. Steaks from heifers fed LUB were wider than CON steaks measured at 25% from the dorsal end at positions 9, 10, and 11 (P < 0.05); but were not different at all other positions (P > 0.08). At 50% the length, LUB steaks measured wider at 7 of the 11 positions (P < 0.04). Additionally, at 75% steak length, LUB steaks were not different than CON steaks at 9 of 11 locations (P < 0.05). Lastly, at 87.5% steak length, LUB steaks were wider than CON from steak 4 to steak 10 (P ≤ 0.05).
Estimated marginal means of USDA Choice strip steak width1 (cm) at 25%, 50%, 75%, and 87.5% of steak length of beef strip steaks from heifers fed lubabegron (LUB) or control heifers (no LUB)
| Width at 25% | Width at 50 % | Width at 75 % | Width at 87.5 % | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Steak Number2 | Control | LUB3 | SEM4 | P Value | Control | LUB | SEM | P Value | Control | LUB | SEM | P Value | Control | LUB | SEM | P Value |
| 1 | 6.40 | 6.40 | 0.10 | 0.95 | 6.75 | 6.84 | 0.11 | 0.55 | 6.43 | 6.57 | 0.10 | 0.32 | 5.59 | 5.86 | 0.10 | 0.05 |
| 2 | 6.66 | 6.63 | 0.09 | 0.81 | 7.09 | 7.17 | 0.10 | 0.57 | 6.50 | 6.57 | 0.10 | 0.63 | 5.46 | 5.67 | 0.10 | 0.13 |
| 3 | 6.78 | 6.80 | 0.10 | 0.91 | 6.95 | 7.25 | 0.10 | 0.03 | 6.55 | 6.69 | 0.09 | 0.29 | 5.53 | 5.72 | 0.10 | 0.20 |
| 4 | 6.55 | 6.67 | 0.09 | 0.32 | 6.60 | 6.95 | 0.10 | 0.01 | 6.47 | 6.67 | 0.09 | 0.13 | 5.55 | 5.92 | 0.10 | 0.01 |
| 5 | 6.35 | 6.56 | 0.11 | 0.17 | 6.23 | 6.52 | 0.10 | 0.17 | 6.11 | 6.33 | 0.10 | 0.10 | 5.36 | 5.63 | 0.10 | 0.05 |
| 6 | 6.01 | 6.09 | 0.09 | 0.56 | 5.84 | 6.10 | 0.09 | 0.04 | 5.77 | 5.99 | 0.09 | 0.08 | 5.02 | 5.38 | 0.10 | 0.01 |
| 7 | 5.77 | 5.96 | 0.11 | 0.21 | 5.72 | 6.06 | 0.09 | 0.01 | 5.50 | 5.76 | 0.10 | 0.06 | 4.64 | 5.05 | 0.10 | <0.01 |
| 8 | 5.59 | 5.73 | 0.09 | 0.09 | 5.42 | 5.80 | 0.09 | <0.01 | 5.03 | 5.40 | 0.09 | <0.01 | 4.39 | 4.70 | 0.10 | 0.02 |
| 9 | 5.27 | 5.61 | 0.10 | 0.02 | 5.31 | 5.60 | 0.08 | 0.02 | 4.85 | 5.06 | 0.09 | 0.11 | 4.19 | 4.71 | 0.19 | 0.05 |
| 10 | 5.05 | 5.40 | 0.10 | 0.01 | 5.05 | 5.31 | 0.09 | 0.04 | 4.55 | 4.65 | 0.09 | 0.45 | 3.96 | 4.21 | 0.09 | 0.03 |
| 11 | 4.88 | 5.17 | 0.10 | 0.05 | 4.79 | 4.80 | 0.11 | 0.97 | 4.42 | 4.56 | 0.10 | 0.29 | 3.94 | 4.15 | 0.10 | 0.14 |
Steak width measured from the medial end of the strip loin steak.
Steak 1 being the anterior end of the strip loin, and steak 11 being the posterior end.
Lubabegron fed for 56 d before harvest.
Standard error (largest) of the estimated marginal means.
Trained sensory evaluation
Trained panelist evaluation estimated marginal means are presented in Table 4. There was no interaction of treatment × aging period (P ≥ 0.78). Moreover, there were no meaningful differences between LUB and CON steaks for all flavor and quality attributes (P ≥ 0.11). Additionally, there were no differences among the 14-d and 28-d aged samples (P ≥ 0.07) within the trained panelist evaluation.
Estimated marginal means of main effects1 of trained panelist evaluation of age and lubabegron supplementation of strip steaks aged 14 or 28 d from conventional heifers
| Treatment | Aging Period | |||||||
|---|---|---|---|---|---|---|---|---|
| Attribute | Control | LUB2 | SEM3 | P Value | 14 D | 28 D | SEM | P Value |
| Beef flavor4 | 52.8 | 53.7 | 0.28 | 0.30 | 53.9 | 52.6 | 0.28 | 0.17 |
| Tenderness | 58.7 | 60.0 | 1.02 | 0.39 | 59.7 | 59.1 | 1.02 | 0.67 |
| Juiciness | 53.6 | 54.7 | 0.87 | 0.37 | 54.5 | 53.8 | 0.87 | 0.56 |
| Browned | 50.8 | 51.5 | 0.77 | 0.47 | 51.7 | 50.6 | 0.77 | 0.31 |
| Roasted | 52.8 | 53.7 | 0.79 | 0.41 | 53.9 | 52.7 | 0.80 | 0.27 |
| Fat-like | 12.7 | 13.3 | 0.27 | 0.11 | 13.1 | 13.0 | 0.27 | 0.69 |
| Umami | 16.0 | 16.5 | 0.28 | 0.30 | 16.5 | 16.0 | 0.28 | 0.17 |
| Buttery | 0.7 | 0.5 | 0.09 | 0.28 | 0.5 | 0.7 | 0.09 | 0.07 |
| Oxidized | 1.6 | 1.7 | 0.16 | 0.90 | 1.7 | 1.6 | 0.16 | 0.35 |
| Liver | 2.3 | 2.3 | 0.20 | 0.89 | 2.3 | 2.3 | 0.21 | 0.90 |
| Metallic | 3.1 | 3.3 | 0.20 | 0.57 | 3.2 | 3.2 | 0.20 | 0.67 |
| Sour | 1.8 | 2.2 | 0.19 | 0.19 | 2.1 | 1.9 | 0.19 | 0.40 |
Interaction of age × lubabegron supplementation P ≥ 0.78.
Lubabegron fed for 56 d before harvest.
Standard error (largest) of the estimated marginal means.
Sensory scores: 0 = extremely dry/tough/none/bland; 50 neither dry nor juicy/neither tough nor tender; 100 = extremely juicy/tender/abundant/ intense.
Slice shear force
Slice shear force results are presented in Figure 2. A treatment × aging period interaction (P < 0.01) was detected in which CON had lesser SSF values than LUB at days 7, 14, and 21 postmortem (P ≤ 0.05), whereas there were no differences between treatments at 28 and 35 d postmortem (P = 0.17).
Interaction of slice shear force values (SSFV) of steaks from conventional heifers fed lubabegron or not over 35 d postmortem aging. Standard error of the mean (largest) = 0.42, P < 0.01.
Discussion
Although no prior research has evaluated steak dimensionality in relation to LUB supplementation, there is overwhelming evidence that supplementation with β-A increases the Longissimus muscle area. It has been previously shown that LUB supplementation increased loineye size in comparison to a control (Kube et al., 2021; Teeter et al., 2021; Vogel et al., 2023). Arp et al. (2014) and Garmyn et al. (2010) reported supplementation with RH and ZH increased loineye area in comparison to a control diet. Martin et al. (2014) reported that RH and ZH increased the Longissimus muscle area, although they observed no changes in steak length. While previous studies have quantified loin eye area from a single rib interface, typically the 12th–13th rib, this approach overlooks potential variation in muscle shape and size along the length of the longissimus. The current study extends these findings by quantifying both cross-sectional area and linear widths and length across the entire strip loin, providing a more comprehensive assessment of β-agonist effects on muscle morphology. The longissimus dorsi is not uniform; cross-sectional dimensions typically decrease toward the anterior and posterior ends of the loin. Measuring multiple positions captures these changes, allowing for more nuanced interpretation of growth patterns and potential redistribution of muscle deposition along the carcass. This design provides insight into whether LUB’s repartitioning effects are localized or consistent throughout the muscle. The increase in longissimus area observed in LUB-supplemented cattle appears to result primarily from greater dorsal–ventral muscle depth rather than anterior-posterior elongation, aligning with the β-A mode of action characterized by increased protein accretion and decreased protein degradation.
In general, the current study demonstrates that LUB exerts different effects on meat quality characteristics than those reported for RH and ZH. Previous studies reporting trained sensory and shear force have reported differences between β-A-treated and control samples. Howard et al. (2014) reported a decrease in overall tenderness for RH and ZH steaks. Similarly, Arp et al. (2013) reported increased overall tenderness in control samples compared to ZH and RH at doses of 300 and 400 mg*steer. Hilton et al. (2009) reported ZH to decrease initial and sustained juiciness, myofibrillar tenderness, overall tenderness, and overall beef flavor. Gruber et al. (2007) reported that RH supplementation decreased tenderness and juiciness by trained panelists. Moreover, RH or ZH supplementation increased SSF and Warner-Bratzler Shear force (Gruber et al., 2007; Hilton et al., 2009; Garmyn et al., 2010; Arp et al., 2013). Additionally, Wendler et al. (2025) saw increases in shear force values by LUB compared to a control, only when fed an additional 14 d on feed. At equal days on feed, no differences in shear force occurred between LUB, RH, and control. Collectively, these findings further establish that β-agonists often negatively impact palatability, likely through increases in muscle deposition and increasing cross-sectional area of muscle fibers.
In contrast, the present study did not identify differences in trained sensory tenderness or juiciness between control and LUB-supplemented samples, despite observing differences in instrumental shear force. This divergence among objective and sensory measures of tenderness could be driven by the magnitude of shear force difference, being less than 2 kg force beyond 14 d of aging. This pattern is partly consistent with Corona et al. (2025), who reported no increase in individual fiber cross-sectional area in the strip loin by LUB treatment, yet observed greater shear force values through 21 d of aging and reduced tenderness scores by trained sensory panelists. Together, these findings suggest that changes in tenderness by LUB may be caused by postmortem proteolytic processes rather than muscle fiber hypertrophy alone. Because LUB likely acts in part by decreasing protein degradation (Dilger et al., 2021), this reduction may extend into the postmortem period by suppressing proteolytic enzyme activity, thereby slowing the degradation of myofibrillar proteins during aging. Beta-agonists have been known to alter calpastatin activity in living and postmortem muscle. In a review, all studies evaluating calpastatin expression and enzyme activity showed an increase, whereas calpains showed more inconsistent results (Cruz et al., 2019). Increased calpastatin activity can reduce the development of postmortem tenderness by reducing calpain-associated proteolysis. This change in postmortem tenderness development supports the current study’s interaction between aging time and LUB treatment, where shear force differences among treatments are overcome by aging of 28 d or greater, likely due to proteolytic mechanisms outside the calpain system.
When interpreted alongside the steak’s dimensionality data, a consistent pattern emerges. LUB increased longissimus muscle area and width without changing steak length, suggesting that muscle growth occurred through increased overall muscling rather than elongation. The expansion in loin area, in the absence of measurable fiber hypertrophy, points to subtle changes in muscle composition or organization that enhance carcass size without negatively impacting palatability. This response contradicts prior work with RH and ZH, documenting increases in fiber cross-sectional area and decreased tenderness (Ebarb et al., 2016; Ebarb et al., 2017). Collectively, these results demonstrate that LUB elicits a distinct β-agonist response, one characterized by increased loin muscle size and modest increases in shear force, without altering palatability and sensory analysis.
Conclusions
Supplementation with LUB increased longissimus muscle area and width without affecting steak length, indicating enhanced muscling deposition across the loin. Although shear force values were greater for LUB-treated steaks, trained sensory panelists detected no differences in tenderness or juiciness, suggesting that these structural changes were not perceptible during eating. Combined with previous reports of increased carcass weight but no evidence of muscle fiber hypertrophy, the current results indicate that LUB promotes muscle growth through mechanisms distinct from previously approved β-agonists. Overall, LUB may offer an avenue to improve carcass yield while maintaining, or with minimal impact on, palatability.
Contributions
Lindsey K. Decker: data curation, validation, writing original draft, writing, reviewing, and editing.
Tayler M. Hayes: data curation, methodology, writing original draft.
Blake A. Foraker: validation, writing, reviewing, and editing.
Bradley J. Johnson: conceptualization, writing, reviewing, and editing.
Justin Homm: conceptualization, funding acquisition, writing, reviewing, and editing.
Phillip J. Rincker: conceptualization, funding acquisition, writing, reviewing, and editing.
Dale R. Woerner: project administration, conceptualization, funding acquisition, writing, reviewing, and editing.
Declaration of Competing Interest
Two of the authors were employed by Elanco Animal Health, which provided funding for this study, at the time this research was conducted.
Acknowledgements
This project was funded by Elanco Animal Health.
References
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