USDA Quality Research Articles

PSV-5 Influence of an oregano-based essential oil on growth performance and carcass traits of beef steers

Abstract The objective of this study was to determine the influence of an oregano-based essential oil on growth performance, health outcomes, and carcass characteristics of yearling beef steers finished in an all-natural program. Single-sourced yearling steers [n = 128; initial body weight (BW) = 335 ± 7.98 kg] were allotted to 16 pens (n = 8 pens/treatment with 8 steers/pen). Steers were blocked by initial BW grouping in a Randomized Complete Block Design (n = 8 blocks total). Groups consisted of 1) control group fed no oregano-based essential oil product (CON) and 2) group fed 4 g/steer daily of By-O-Reg+ Beef (Advanced Ag Products, Canton, SD; OEO). Steers were individually weighed on d 0 (arrival), d 38, d 66, d 108, and d 149 for growth performance measures. Steers were transitioned from a 70% concentrate diet to a diet that contained 90% concentrate over 14 d and remained on the finishing diet until harvest on d 149. The finishing diet provided 1.37 Mcal/kg of NEg. Steers were evaluated daily for indications of disease or visible digestive disorders by a trained technician blinded to the treatments. Steers were fed until visually assessed to have 1.27 cm rib fat and were shipped for harvest at a commercial processing facility. Liver scores and hot carcass weights were recorded at the time of harvest and steer identity was maintained throughout the harvest process. Following an approximately 24 h chilling period, carcass data were recorded, and USDA Yield and Quality Grade were determined. Health outcomes were not influenced by dietary treatment (P ≥ 0.18). Inclusion of OEO did not influence (P ≥ 0.73) carcass-adjusted final BW, DMI, average daily gain (ADG), gain:feed, observed dietary NEm or NEg, observed-to-expected dietary NEm or NEg. In addition, no differences (P ≥ 0.30) were observed between treatment groups for hot carcass weight, dressing percentage, ribeye area, rib fat thickness, calculated yield grade, marbling score, estimated empty body fat percentage, or distribution of USDA Yield and Quality Grades. The OEO treatment tended (P = 0.11) to have a decreased percentage of normal liver scores compared with CON. Collectively, growth performance and carcass traits of yearling steers finished in an all-natural program in this experiment were not influenced by dietary inclusion of an oregano-based essential oil.

PSV-7 greatOPlus (extruded blend of flaxseed and Nannochloropsis oculata biomass) improves finishing cattle performance and carcass characteristics

Abstract Our objective was to investigate impact of feeding greatOPlus (GOP), an extruded mixture of flaxseed and Nannochloropsis microalgae biomass (NBO3 Technologies LLC; Manhattan, KS) on feedlot cattle performance and carcass characteristics. Yearling steers (n = 700; 374 ± 8.2 kg initial body weight) were blocked by initial body weight and assigned randomly, within block, to 28 feedlot pens containing 25 animals/pen. Cattle were vaccinated against viral and clostridial pathogens and treated for internal and external parasites (Bovishield Gold 5, Ultrabac 7 Somubac, and Dectomax injectable; Zoetis Animal Health), and implanted with a combination implant (Component TE-200; Elanco USA). The control diet (CON) consisted of 58.3% steam-flaked corn, 20% wet corn gluten feed, 2.56% soybean meal, and 4.17% vitamin/mineral/feed additive premix. For the GOP diet, a portion of the corn and all of the soybean meal were replaced with 10% GOP (dry basis) to create isonitrogenous diets. Cattle were fed once daily, ad libitum. After 175 d on feed, animals were weighed and transported to a commercial abattoir for harvest. Animal performance measurements included average daily gain (ADG), dry matter intake (DMI), and gain to feed ratio (G:F). Hot carcass weight (HCW) and incidence of abscessed livers were assessed on the day of harvest, and marbling score, 12th rib fat thickness, longissimus muscle area, and USDA yield and quality grades were determined following 48 hours of refrigeration. Cattle fed GOP had greater DMI and ADG (P< 0.05) compared with cattle fed CON, but G:F was not affected by treatment (P > 0.10). Cattle fed GOP had greater HCW compared with those fed CON (422.8 vs 409.5 kg; P < 0.01) and tended to produce more Prime and Choice carcasses (87.4 vs 83.0%; P = 0.11) with greater 12th rib backfat (1.55 vs 1.49 cm; P < 0.02) and greater yield grades (2.91 vs 2.75; P < 0.01). Marbling score (488 vs 491), longissimus muscle area (94.1 vs 93.4 cm2) and liver abscess incidence (12 vs 16% for CON and GOP, respectively) were unaffected by treatment (P > 0.10). Carcass values were calculated using base prices, premiums, and discounts published by USDA, and were greater for cattle fed GOP compared with cattle fed the control diet ($2,122 vs $2,059; P < 0.01). Including greatOPlus at 10% of the diet dry matter improved cattle performance, largely as a result of its impact on DMI and ADG.

60 Effects of phase feeding rolled hybrid rye on feedlot performance in backgrounded beef steers

Abstract The objective of this study was to evaluate the effects of phase-fed rolled hybrid rye on feedlot performance and carcass characteristics of finishing steers. Backgrounded steers [n = 110; initial shrunk (4% of body weight; BW) = 391 ± 1.3 kg] were assigned to 1 of 14 pens at the Southeast Research Farm, Beresford, SD in a randomized complete block design. Pens were blocked by location with four blocks of dirt-surfaced, outside pens (8 pens; 10 steers/pen) and three blocks of concrete-surfaced, partially covered pens (6 pens; 5 steers/pen). Pens were randomly assigned to one of two dietary treatments (7 pens/treatment): dry rolled corn (DRC) included at 66% diet dry matter (DM) or rolled hybrid rye (RRYE) included at 66% diet DM for the initial 46 d of the experiment followed by the DRC diet from d 47 to trial completion on d 144. One steer was removed from the study because of lameness. During the rye feeding period (d1 to d 46), RRYE decreased average daily gain (ADG) by 13% (P = 0.01; 1.59 and 1.83 kg, respectively) and DMI by 18% (P = 0.01; 8.45 and 10.30 kg, respectively) with no effect (P = 0.15) on gain to feed ratio (G:F) compared with DRC. Negative effects of RRYE were more pronounced during the first 20 d of the experiment with ADG reduced by 29% (P = 0.01; 1.13 and 1.60 kg, respectively), DMI by 15% (P = 0.01; 8.20 and 9.61 kg, respectively), and G:F by 17% (P = 0.01; 0.139 and 0.167, respectively). Dietary net energy values for RRYE were increased (P ≤ 0.03) from d 1 to 46. Feeding rye reduced BW on d 46 by 10 kg compared with DRC (P = 0.01; 474 and 464 kg, respectively). From d 47 to 144 when all steers were fed a common diet there were no differences (P ≥ 0.38) in any growth performance responses or measures of dietary net energy utilization. When measured over the entire experiment, DMI tended to be less (P = 0.08) for RRYE compared with DRC with no effect on ADG or G:F (P ≥ 0.19). Final BW was numerically reduced in the RRYE treatment compared with DRC (P = 0.21; 614 and 623 kg, respectively). Cumulative observed-to-expected ratios for NEm and NEg were increased (P = 0.05) for RRYE compared with DRC. Dietary treatments did not affect (P ≥ 0.29) carcass characteristics, distribution of USDA yield or quality grades, or liver abscess incidence or severity. Feeding rolled rye decreased ADG, DMI, and G:F during the first 46 DOF with similar growth performance when fed a DRC-based diet for the final 98 d.

65 Effect of two different implant programs on growth performance and carcass characteristics in beef steers fed to three differing harvest endpoints

Abstract Two implant programs (Merck Animal Health, DeSoto, KS and Zoetis, Parsippany, NJ) and 3 d on feed (DOF) endpoints were used to evaluate growth performance and carcass characteristics of finishing beef steers. Beef steers [n = 480; initial body weight (BW) = 402; SEM = 2.4 kg] were assigned to treatment pens (10 steers/pen) with pen (n = 48 pens total) as the experimental unit. Treatments were arranged as a 2 x 3 factorial including implant program: 1) a single Revalor-XS (200 mg trenbolone acetate and 40 mg estradiol-17β total) on d 0 (XS) compared with 2) Synovex-Choice (100 mg trenbolone acetate and 14 mg estradiol benzoate) on d 0 and re-implanted with a Synovex-ONE Feedlot (200 mg trenbolone acetate and 28 mg estradiol benzoate) 70 d later (CHSOF) and harvest endpoint: 1) 162 DOF, 2) 183 DOF, or 3) 204 DOF. Both implant groups were removed from their pens on the day of reimplantation. Data were analyzed as a RCBD. Final BW was calculated as HCW/0.625. An implant × DOF (P ≤ 0.04) interaction was noted for gain to feed ratio (G:F), REA, final BW adjusted to 28% estimated empty body fatness (AFBW), and USDA quality grade distribution, a tendency for an interaction was observed for final BW, average daily gain (ADG), HCW, and dressing percentage (P ≤ 0.09), no other interactions were noted for any traits evaluated (P ≥ 0.17). Steers from CHSOF/162 had increased G:F by 4.1 to 6.5% compared with others (P ≤ 0.05). Steers from XS/204 had greater REA by 3% to 10% (P ≤ 0.05) compared with all other treatments and greater AFBW by 3% to 7% (P ≤ 0.05), compared with all other treatments except CHSOF/204. Steers from XS had a greater proportion of carcasses grading USDA Prime at 162 and 183 DOF compared with CHSOF. As a result of increased DOF, the XS/204 and CHSOF/204 steers had greater final BW and HCW compared with all other treatments (P ≤ 0.05), steers from XS/183 had greater HCW than XS/162 and CHSOF/162; however, CHSOF/183 did not differ from CHSOF/162 (P ≤ 0.05). Steers from CHSOF/162 had greater ADG by 5.8% compared with CHSOF/183 (P = 0.05), while all others were intermediate. Dressing percentage was the greatest for XS/204 and least for CHSOF/183 (P ≤ 0.05). Cattle from XS had increased (P < 0.01) DMI by 2.6%. As DOF increased, carcass-adjusted final BW increased while ADG decreased (linear; P = 0.05). As DOF increased, REA and AFBW increased (P < 0.01). Increasing DOF, increased (P < 0.01) USDA yield grade 4 and 5 carcasses and decreased yield grade 2 and 3 carcasses. Implant strategy had a marginal influence on growth performance and carcass characteristics; however, as DOF increased carcass weights, rib fat, and ribeye area increased.

103 Effects of partial or total replacement of dried distiller’s grain with soybean meal on growth performance, carcass characteristics, sera urea nitrogen, and net energy utilization in finishing beef steers

Abstract The objective of this study was to determine if partial or complete replacement of dried distiller’s grains plus solubles (DDGS) with solvent-extracted soybean meal (SBM) influences growth performance, efficiency of dietary net energy utilization, sera urea-N (SUN) concentrations, or carcass traits in finishing beef steers. Continental × British steers [initial shrunk body weight (BW) = 382 ± 37 kg] were used in a 139-d experiment. Treatments included: DDGS fed at 20% DM (13.4% CP; DDGS), SBM replacing 50% of DDGS (14.4% CP; SBM50), and SBM replacing 100% of DDGS (15.4% CP; SBM100). Steers (n = 189) were weighed and allotted to 1 of 24 pens (n = 8 steers per pen; 8 pens per treatment) at the Ruminant Nutrition Center near Brookings, SD. Whole blood was collected and harvested as sera on d 77, 105, and 139 to determine SUN concentration. Growth and carcass data were analyzed as a randomized complete block design using the GLIMMIX procedure of SAS 9.4 with treatment and block (initial BW grouping) as fixed effects; SUN data were analyzed using repeated measures, pen was the experimental unit. Inclusion level was evaluated for linear and quadratic components by the method of orthogonal polynomials. Final BW was calculated by dividing hot carcass weight (HCW) by 0.625. No differences were noted (P ≥ 0.18) for final BW, average daily gain, dry matter intake, or feed efficiency. Dietary treatment tended to affect gain to feed ratio (G:F; quadratic; P = 0.10) and SBM increased the apparent efficiency of energy capture. Treatment had no effect (P ≥ 0.22) on HCW, rib fat, marbling score, USDA yield grade, or final BW adjusted to 28% empty body fat. Complete replacement of DDGS with SBM increased rib eye area by 1% (linear; P = 0.02), but decreased dressing percentage (linear, P = 0.03). Distribution of USDA quality or yield grades were unaffected by treatment (P ≥ 0.36). No treatment × day interaction was observed for SUN (P = 0.20). However, day (P < 0.01) and treatment (P < 0.01) effects were observed. Initial samples (d 77) differed between DDGS and SBM treatments, with the latter having greater SUN values (P < 0.01). On d 105, the SBM100 treatment had greater SUN than DDGS, and SBM50 was intermediate (P < 0.01). On d 139, steers from SBM100 had elevated increased SUN compared with SBM50 and DDGS treatments (P < 0.01). Net energy values calculated from animal performance for DDGS agreed closely with tabular estimates. In this experiment, replacement of DDGS with SBM increased the observed to expected ratio of dietary NE, increased muscularity and tended to decrease DP with no other observed effects on growth performance or carcass traits.

59 Effects of serial harvest on growth and carcass characteristics of beef x dairy crossbred steers

Abstract Beef x dairy crossbred feedlot steers [n = 707; body weight (BW) at initial processing = 148 kg] were utilized in a randomized complete block design to evaluate effects of three serial harvest endpoints on growth performance and carcass characteristics. Allocation to treatment occurred after 204 d-on-feed (DOF), at which point steers weighed 484 kg (SEM = 3.2 kg). Treatments consisted of three serial harvest endpoints: 326, 347, and 368 DOF, as measured from initial processing at 148 kg. Twelve pens, with approximately 59 steers/pen and four pens/treatment were utilized. Final BW measured 696, 730, and 744 kg at 326, 347, and 368 DOF, and increased (P < 0.01) with DOF. Dry matter intake (DMI) from allocation to harvest did not differ among treatments (11.4 kg/d; P = 0.36). Average daily gain (ADG) from allocation to harvest measured 1.82, 1.79, and 1.64 kg at 326, 347, and 368 DOF, respectively and was greater (P < 0.01) at 326 and 347 DOF than at 368 DOF. Feed efficiency (FE) from allocation to harvest measured 0.162, 0.151, and 0.143 at 326, 347, and 368 DOF, respectively and was greater (P < 0.01) at 326 and 347 DOF than at 368 DOF. Hot carcass weight (HCW) measured 438, 459, and 472 kg at 326, 347, and 368 DOF, respectively and increased (P < 0.01) with DOF. Across the 42-d serial harvest period live and carcass ADG averaged 1.09 and 0.78 kg, respectively, with a carcass transfer of 71.6%. Backfat thickness measured 1.35, 1.63, and 1.47 cm at 326, 347, and 368 d, respectively and was greater (P < 0.01) at 347 and 368 d than at 326 d. Marbling score measured 508, 529, and 550 at 326, 347, and 368 DOF, respectively and was greater (P = 0.03) at 368 and 347 DOF than at 326 DOF. Distribution of USDA quality grades (QG) did not differ (P = 0.45) among treatments and averaged 6.3% Prime and 83.1% Choice. Ribeye area and dressing percentage (P = 0.11) did not differ among treatments. Distribution of USDA yield grades (YG) was affected by treatment (P < 0.01), with a shift toward more YG 4 and 5 carcasses with increasing DOF. Liver abscess occurrence averaged 62.9% and did not differ (P = 0.61) among treatments. Results from this experiment indicate a BW gain of 1.09 kg/d and a HCW gain of 0.78 kg/d across the 42-d serial harvest period. There were no differences in DMI as DOF progressed but ADG and FE decreased in the longest-fed cattle. Distribution of QG was not affected by DOF, but YG increased with increasing DOF.

Influence of Beef Hot Carcass Weight on Sensory Characteristics of Strip Loin, Eye of Round, and Denver Cut Steaks.

The objective of this research was to investigate the influence of beef hot carcass weight (HCW) on consumer sensory attributes. Beef carcasses (n = 116) were selected based on the USDA quality grade and HCW. Lightweight (LW; 296-341 kg), middleweight (MW; 386-432 kg), or heavyweight (HW; 466-524 kg) carcasses with USDA Choice (LC) or USDA Select (SEL) quality grades were used in this study. Carcasses were tracked through fabrication and the semitendinosus, chuck roll, and strip loin were collected and fabricated into eye of round, Denver cut, and strip loin steaks, respectively, for consumer sensory evaluation. USDA Select MW Denver cut steaks had increased overall liking and texture liking scores and were more tender and juicier than the SEL LW steaks (p ≤ 0.02). USDA Select MW strip loin steaks had increased overall and flavor liking scores and were more tender than the SEL LW steaks (p ≤ 0.02). USDA Choice MW eye of round steaks had increased overall, flavor, and texture liking scores and were juicier than the LW eye of round steaks (p ≤ 0.04). The steaks evaluated in this study were differentially impacted by HCW and little to no clear pattern of effects could be determined across cut or quality grade. Additional research is needed to determine the most acceptable HCW from a consumer perspective.

Flavor Development of Ground Beef from 3 Muscles, 3 USDA Quality Grades, and 2 Wet-Aging Durations

The objective of this study was to understand the influence of USDA quality grade, muscle, and aging duration on ground beef flavor development. Prime (PR), Low Choice, and Standard quality grade beef subprimals were collected and aged for either 21 or 42 d. Following aging, subprimals were fabricated into gluteus medius (GM), biceps femoris (BF),and serratus ventralis (SV) then ground and formed into patties. Raw patties were designated for proximate composition, fractionated fatty acids, and thiobarbituric acid reactive substances (TBARS). Cooked patties were designated for consumer sensory analysis, volatile compound analysis, and TBARS. Patties were cooked on a preheated griddle to 72°C. All data were analyzed as split-split plot where quality grade served as the whole plot factor, muscle as the subplot factor, and aging duration as the sub-subplot factor. Significance was determined at P<0.05. A quality grade×muscle interaction was observed for moisture, where regardless of muscle, PR subprimals had the lowest moisture percentage (P<0.05). Raw TBARS was not influenced by any interactions or main effects (P>0.05). Individually, the BF and 42 d aged subprimals had the greatest cooked malondialdehyde concentration (P<0.05). Patties from GM aged for 21 d were rated higher for flavor liking compared to GM aged for 42 d and SV aged for 21 and 42 d (P<0.05). GM patties aged for 21 d were rated higher for overall liking compared to GM patties aged for 42 d (P<0.05). Quality grade did not influence any lipid-derived volatile compounds (P>0.05). The SV produced less Maillard reaction products (P<0.05). Aging for 42 d increased lipid-derived volatiles (P<0.05). Consumer liking of aged product is dependent on muscle. Aging recommendations should be muscle-specific to maximize beef eating experience.

National Beef Tenderness Survey—2022: Consumer Sensory Panel Evaluations and Warner-Bratzler Shear Force of Beef Steaks From Retail and Foodservice

Beef retail steaks from establishments across 11 US cities and beef foodservice steaks from establishments in 6 US cities were evaluated by consumer sensory evaluations and Warner-Bratzler shear (WBS) force analyses. The retail tenderloin had the lowest (P<0.05) WBS force value compared to other retail cuts. The retail steak with the greatest (P<0.05) WBS force value was the top sirloin. Foodservice ribeye and top loin steaks had greater (P<0.05) WBS force values compared to the tenderloin. All retail top blade, bone-in ribeye, Porterhouse, and tenderloin steaks were categorized as“very tender” (<31.4 N). There were no (P>0.05) differences in WBS force values among USDA quality grade groups for foodservice steaks. Retail tenderloin steaks received the highest (P<0.05) consumer rating for overall like/dislike, tenderness like/dislike,tenderness level, flavor like/dislike, and juiciness like/dislike compared to all other retail cuts. There were no (P>0.05)differences among the 4 foodservice cuts for consumer sensory ratings of overall like/dislike, tenderness like/dislike, tenderness level, flavor like/dislike, and juiciness like/dislike. There were no (P>0.05) USDA quality grade differences for ribeye, top loin, top sirloin, and tenderloin foodservice steaks for overall like/dislike, tenderness like/dislike, tenderness level, flavor like/dislike, and juiciness like/dislike. Regardless of source (foodservice or retail), USDA grade group, or beef cut, measures of tenderness in this survey reveal ratings and values that should meet most consumer expectations in the marketplace.

Dose effects of encapsulated butyric acid and zinc on beef feedlot steer growth performance, dietary net energy utilization, rumen morphometrics, small intestine histology, and carcass characteristics.

The objective of this study was to determine the effects that increasing doses of encapsulated butyric acid and zinc (BZ) have on feedlot steer growth performance, rumen morphometrics and small intestine histology (data not statistically analyzed), dietary net energy utilization, and carcass characteristics. Steers [n = 272; shrunk body weight (BW) = 360 kg ± 74 kg] were assigned to dietary treatments [0 (CON), 1, 2, or 3g BZ/kg diet dry matter] in a randomized complete block design (RCBD) with pen (n = 32 total; n = 8 per treatment) as experimental unit. Pens were blocked by cattle source and location within the feedyard. Cattle were fed until visually assessed to have 1.27cm rib-fat and were shipped for harvest at a commercial beef abattoir. Carcass and liver health data were recorded. A subset of steers (n = 8 total; n = 2 per treatment) was harvested at the SDSU Meat Laboratory to collect empty body measurements, rumen samples for morphometric analysis, and duodenal and ileal samples for histological analysis to provide context to feeding trial outcomes. Feedlot growth performance data was calculated on a carcass-adjusted basis: hot carcass weight (HCW)/0.625. Data were analyzed as a RCBD with fixed effects of BZ inclusion level and block was considered a random effect; pre-planned contrasts for CON vs. BZ, plus linear, and quadratic responses were tested. No differences (P ≥ 0.11) were observed for final BW, dry matter intake, average daily gain (ADG), feed conversion efficiency (G:F), performance calculated dietary net energy, HCW, ribeye area, rib-fat thickness, marbling score, estimated empty body fat, or distribution of USDA yield grade (YG) 1, 3, 4, 5, and USDA quality grade among treatments. A tendency (P = 0.10) was observed for CON vs. BZ for calculated YG. Tendencies were detected for USDA YG 2 carcass distribution (linear; P = 0.07) and for normal and abscessed liver prevalence (quadratic; P = 0.08). Dressed yield tended to be greater (P = 0.08) for BZ vs. CON and increased with dose (linear; P = 0.05). Receiving period shrunk BW, ADG, and G:F was improved (P ≤ 0.02) for BZ-supplemented steers compared to CON. Data from this study suggests that the addition of BZ to feedlot finishing diets to improve receiving period growth performance and decreasing the prevalence of abscessed livers should be further investigated.

National Beef Quality Audit-2022: in-plant assessments of quality and yield determining carcass characteristics of fed steers and heifers.

The National Beef Quality Audit -2022 serves as a benchmark of the current fed steer and heifer population of the U.S. beef industry and allows comparison to previous audits as a method of monitoring industry progress. In-plant cooler assessments and collections of beef carcass data took place from July 2021 to November 2022. During in-plant evaluations, 10% of 1-d production was surveyed for quality and yield indicating characteristics of fed beef carcasses (n = 9,746 beef carcasses). Distributions of sex classes among sampled carcasses were steer (65.0%) and heifer (35.0%), whereas distributions of breed type were native (87.7%), dairy (11.3%), and Bos indicus (0.9%). Mean values were observed for USDA Yield Grades (YG; 3.3), USDA Quality Grade (QG;Choice16), marbling score (Small98), ribeye area (91.0cm2), adjusted fat thickness (1.49cm), hot carcass weight (401.9kg), and KPH (2.5%). Mean overall maturity was A66, with a mean lean maturity of A56 and mean skeletal maturity of A72. There were 28.1% of carcasses identified for use in a USDA-certified beef G-Schedule Program. Defects, such as dark cutting and blood splash, were observed at 1.8% and 0.5%, respectively. Distributions of USDA YG were YG 1 (8.2%), YG 2 (30.7%), YG 3 (40.2%), YG 4 (16.6%), and YG 5 (4.3%). USDA QGs were observed at 7.5% Prime, 69.2% Choice, 16.4% Select, and 6.8% other. The results of this study provide an updated look at the current grading trends of beef carcasses in the United States to drive progress in the fed beef industry.

PSVII-19 Evaluation of Live and Carcass Performance of Holstein Steers Fed Lubabegron During the Finishing Period

Abstract The objective of this study was to evaluate the effect of duration of lubabegron supplementation on live and carcass performance of Holstein steers. Holstein steers (n = 330) were enrolled in a feeding program supplementing lubabegron daily into a total mixed ration (TMR) at 3.2 g/ton for 0 (control) 28, 56, or 84 d. Steers were stratified by initial body weight (BW = 538 ± 37 kg) and then randomly assigned to treatments and pens. There were 8 pens total with approximately 40 head per pen. A GrowSafe feed intake recording system was used for the duration of the study to collect daily feed intake and feeding behavior on individual animals. Samples of premix were taken weekly for treatments to ensure nutrient requirements were being met and lubabegron concentration was accurate. Prior to departure from the feedlot and immediately upon arrival at the harvest facility, mobility of all animals was assessed. Individual IDs were matched with carcass identification and used throughout the harvest process to ensure the integrity of individual data. Carcasses were chilled for 48 hours and then went through USDA quality and yield grading protocols. Cattle fed lubabegron for 28 and 56 d had the greatest (P ≤ 0.01) average daily gain, total gain, as well as the least feed to gain ratio (P = 0.01) as compared with control steers and those fed lubabegron for 84 d. Conversely, control steers had the greatest (P < 0.05) feed-to-gain ratio. No differences (P ≥ 0.08) were observed between supplementation time for initial body weight, final body weight, and dry matter intake. Additionally, mobility scores were not different among supplementation protocols, neither at the feed yard, nor the harvest facility (P ≥ 0.64). Steers within the 28 d and 56 d treatments had among the greatest (P = 0.02) hot carcass weight. Ribeye area was increased (P = 0.01) by at least 3.87 cm2, when the cattle were fed lubabegron for any period of time. Cattle fed lubabegron for 56 and 84 d had an increased (P = 0.01) dressing percentage compared with 28 d and controls. While overall marbling scores were decreased (P = 0.04), the percentage of carcasses receiving USDA Prime, Choice, or Select quality grades were not different for animals receiving supplementation (P ≥ 0.31). The data suggest that lubabegron can positively influence live growth attributes; thus, translating to increased carcass yield, without sacrificing animal mobility or carcass quality.

172 Effects of Anesthetic and Analgesic Administration at Castration on the Dry Matter and Water Intake, Growth, Feed Efficiency, and Carcass Characteristics of Beef Steers

Abstract The objective of this study was to determine the effects of anesthetic and analgesic administration at castration on the dry matter and water intake, growth, feed efficiency, and carcass characteristics of beef steers. Angus (n = 14) and Simmental x Angus (n = 12) bulls (200 to 278 days of age) were randomly assigned to 2 treatments by breed. Control (CON) bulls were castrated by elastration with no pain management. Pain managed (PM) bulls were castrated by elastration, but also received an anesthetic (lidocaine + 10% sodium bicarbonate; 15 to 20 mL) injection and an oral analgesic (meloxicam; 0.992 mg per kg BW). Initial BW = 325.4 ± 36.9 kg and 299.3 ± 48.2 kg for CON and PM bulls, respectively. Steers were provided with ad libitum access to feed and water using an Insentec RIC system (Hokofarm, Marknesse, Netherlands). Beginning 2 weeks after castration, steers received 2 diets containing increasing energy concentrations at weekly intervals until reaching a finishing diet. Steers were implanted 28 d after castration. Dry matter intake (DMI), diet water intake (DWI), liquid water intake (LWI), and total water intake (TWI) were collected from d -7 to d 195. Depression scores were determined at 6, 18, and 30 h after castration. Body weights were collected on d -7, d 0, d 7, d 14, d 21, d 28, and d 195. Camera carcass data and USDA Yield and Quality Grades were collected at slaughter. Data were analyzed using the PROC MIXED procedure of SAS and significance was declared at P < 0.05. Dry matter intake, water intake, and BW were analyzed by periods beginning 1 week before castration (d -7 to d -1). Periods 2, 3, and 4 were the weeks following castration (d 0 to d 6, d 7 to d 13, and d 14 to d 20, respectively). Period 5 was from d 21 to d 195 and overall was from d 0 to d 195. Dry matter intake, DWI, LWI and TWI were unaffected by treatment. Average daily gain (P = 0.0178) and G:F (P = 0.0130) were influenced by treatment x period interactions. Pain managed steers gained faster (ADG: 1.26 vs 0.48 kg/d; P = 0.0069) and more efficiently (G:F: 0.148 vs 0.051; P = 0.0032) than CON cattle in the week following castration. Depression scores, carcass characteristics, overall ADG, and overall feed and water intake were not different. Pain management at time of castration improves ADG and G:F in the short term; however, the effects are not different over the duration of the feeding period. Further research is needed to determine the best method of castration pain management for beef cattle.

346 Substitution of Modified Distillers Grains with Soybean Meal with Or Without Hulls Had Negligible Effect on Growth Performance, Efficiency and Carcass Traits in Yearling Steers

Abstract Changes to the fuel landscape in the United States have resulted in changes in long-held supplemental protein price relationships. The objective of this study was to evaluate substituting oilseed meal for corn processing co-products. Predominately Angus steers [initial shrunk body weight (BW) = 435 ± 23.6 kg] were used in a 118-d experiment using three treatments: modified distillers grains (MDGS)fed at 15% diet DM (MDGS) replaced by either soybean meal and corn (9 and 6% of DM, respectively; SBM), or soybean meal and soyhull pellets (9 and 6% of DM, respectively; SBM-SBH). Steers (n = 240) were individually weighed and allotted to one of 24 pens (n = 10 steers per pen; 8 pens per treatment) at the Southeast Research Farm located near Beresford, SD. Dietary concentrations of crude protein and neutral detergent fiber based on tabular values and weekly batching records were 12.3 and 17.6%, 12.8 and 14.5%, and 12.8 and 17.8% for MDGS, SBM, and SBM-SBH, respectively. Data were analyzed as a randomized complete block design using the GLIMMIX procedure of SAS 9.4 with treatment and block as fixed effects; pen was the experimental unit. Pen conditions were wet and muddy during the final weeks of this experiment; consequently, final BW was calculated by dividing hot carcass weight (HCW) by a common dressing percentage of 62.5. No differences amongst treatments (P ≥ 0.11) were found for carcass-adjusted final BW, dry matter intake (DMI), average daily gain (ADG), or feed efficiency. Dietary treatment had no effect (P ≥ 0.11) on HCW, dressing percentage, ribeye area, rib fat, marbling score, USDA Yield Grade, percent empty body fat (EBF), or final BW adjusted to 28% EBF. Distribution of USDA Quality and Yield grades were unaffected by treatment (P ≥ 0.39). Dietary treatment did not affect liver abscess incidence and severity (P = 11). Net energy values calculated from animal performance agreed closely with tabular estimates with observed to expected ratios for net energy equaling one. In this experiment, feeding supplemental protein sources with enhanced diet conditioning attributes and greater concentrations of ruminally undegradable protein provided no advantage to cattle performance. These results indicate that protein source decisions can be based upon price per unit of delivered crude protein.

PSXII-14 Effects of Feeding 10-G on Performance and Carcass Quality of Yearling Beef Steers

Abstract Life Products’ direct fed microbial, 10-G, is a lipid-coated and heat protected mixed culture containing Lactobacillus acidophilus, Enterococcus faecium, Pediococcus pentosaceus, Lactobacillus brevis, and Lactobacillus plantarum. Previous small-pen research has reported inconsistent benefits to performance and carcass characteristics from feeding 10-G. The objective of this trial was to evaluate the effects of feeding 10-G on growth performance and carcass quality in yearling steers. In this randomized complete block design, 6,400 yearling steers were allocated to treatment (10-G or control) within a block (n = 16), where pen served as experiment unit. Trial diets were composed of steam-flaked corn, wheat silage, corn silage, and Sweet Bran Plus. The addition of 10-G within the treatment diet was at an inclusion of 2 g·animal-1·day-1 to provide 1x109 cfu for approximately 170 days. Mean initial body weight was 358 kg and cattle were on feed for an average of 182 days. No differences (P > 0.10) were observed between treatments for dry matter intake (control: 9.75 vs 10-G: 9.80 kg), final body weight (control: 641vs 10-G: 641 kg), average daily gain (control: 1.55 vs 10-G: 1.55 kg/d), or feed efficiency (control: 2.85 vs 10-G: 2.87). When evaluating carcass characteristics, there were no differences (P > 0.10) for hot carcass weight (control: 415 vs 10-G: 413 kg) or liver abscess prevalence (control: 17.4 vs 10-G: 18.2%). However, dressed carcass yield was decreased (P = 0.05) by 0.17% for cattle fed 10-G (control: 64.51 vs 10-G: 64.34%). No differences (P > 0.10) were observed for marbling score (control: Small29 vs 10-G: Small27), ribeye area (control: 100.00 vs 10-G: 100.00 cm2), backfat thickness (control: 1.30 vs 10-G: 1.30 cm). USDA quality grade outcomes. In conclusion, the supplementation of 10-G direct fed microbial did not influence live or carcass performance within this trial.

365 Effects of Supplementing Carinata Meal Compared with Cottonseed Meal on Performance, Carcass Characteristics, and Sensory Attributes in Beef Steers Consuming a Finish Diet

Abstract The value of carinata, a non-food oilseed crop, has been demonstrated as a high-quality jet fuel alternative and successful cover crop in the southeastern U.S.; however, research is limited regarding carinata as an alternative for commonly used protein sources in livestock. Thirty-two Angus crossbred steers were used in a generalized randomized block design to evaluate the effects of supplementing carinata meal compared with cottonseed meal on performance, carcass characteristics, and meat sensory attributes in a finishing diet. Treatments included: either 90% basal diet + 10% inclusion of Brassica carinata meal (BCM) or 90% basal diet + 10% inclusion of cottonseed meal (CSM), on a dry matter (DM) basis. The basal diet consisted of 40% cracked corn, 35% soyhull pellets, 5% gin trash, 5% bermudagrass hay, and 5% vitamin-mineral supplement. Treatments were premixed before delivery and provided ad libitum, with individual intake measured using the GrowSafe system. Data were analyzed using Proc Glimmix of SAS. Protein source did not affect (P > 0.05) final body weight, dry matter intake, average daily gain, gain to feed ratio, or residual feed intake. Protein supplementation did not affect (P > 0.05) initial or final evaluations of longissimus muscle area (LMA), rib fat thickness (RF), and intramuscular fat performed via ultrasound during the performance portion of the experiment. Hot carcass weight (P = 0.10) dressing percentage (P = 0.61), LMA (P = 0.33), RF (P = 0.42), yield grade (P = 0.47), and marbling score (P = 0.89) were not affected by protein source. No effect of protein source was observed (P > 0.05) on slice shear force, juiciness, beef flavor, tenderness, connective tissue, off-flavor, crude fat, thaw loss, cook loss, lightness, redness, or yellowness. The frequency of Prime (P = 0.76), upper 2/3 Choice (P = 0.71), low Choice (P = 0.46), and Select (P = 0.34) USDA quality grades did not differ with protein source. carinata meal inclusion at 10% of the diet DM performed similarly to cottonseed meal in steers fed a finishing diet, thereby enhancing its value in the southeastern U.S.

311 Evaluation of Rumen Protected B-Vitamin Blend on Finishing Steer Growth Performance, Efficiency of Dietary net Energy Utilization, Carcass Trait Responses, and Liver Abscess Prevalence and Severity

Abstract The objective of this study was to determine the influence that a rumen-protected B-vitamin (RPBV) blend (containing pantothenic acid, pyridoxine, folic acid, biotin, and cyanocobalamin; Vivalto, Trouw Nutrition, Isola Vicentina, Italy) had on growth performance, efficiency of dietary net energy utilization, carcass trait responses, and liver abscess severity and prevalence in beef steers fed a finishing diet. Steers (n = 246; initial shrunk body weight (BW) = 411 ± 25.8 kg) from two sources, were used in a 126-d randomized complete block design experiment. Within 48 h after arrival, steers were individually weighed and allotted to one of 24 pens (n = 10 to 12 steers; 8 pens/treatment) and randomly assigned to 1 of 3 treatments: 1) No RPBV; 2) RPBV1 at 1 g/hd/d; 3) RPBV2 at 2 g∙animal-1∙d-1/. During the first 14 d cattle received two transition diets. From d 15 to d 126 cattle were fed the final diet containing 53% dry-rolled corn; 23% corn silage; 20% MDGS; and 4% suspended supplement. Data were analyzed using the GLIMMIX procedure of SAS 9.4 with treatment as the fixed effect and block (Pen location) as the random effect; pen was considered the experimental unit. No differences (P ≥ 0.13) were found for dry matter intake, final live BW, average daily gain (ADG), or feed efficiency (G:F) among treatments. Carcass-adjusted final BW, ADG, and G:F were not influenced by treatment (P ≥ 0.59). Hot carcass weight, dressing percentage, marbling score, kidney-pelvic-heart fat, or BW at 28% empty body fat did not differ among treatments (P ≥ 0.11). Rib eye area (REA) was altered (quadratic effect, P = 0.02) by treatment; steers from RPBV 1g had decreased REA compared with others. Additionally, calculated yield grade (YG) and calculated retail yield (RY) were altered (quadratic effect, P ≤ 0.01) by treatment; steers from RPBV 1 g had increased YG and decreased RY compared with others. Estimated empty body fatness tended (P = 0.06) to be greater from steers fed RPBV compared with control. Overall USDA YG distribution was altered by dietary treatment (P = 0.01). The proportions of YG1 and YG5 carcasses were unaffected by treatment, but there was a shift in the proportion of carcasses that graded YG2, YG3, and YG4 among treatments. Distribution of USDA Quality Grade was not altered by treatment (P = 0.53). No differences were observed on liver abscesses among treatments. The use of RPBV altered carcass muscularity and rib fat accumulation which impacted the overall YG distribution. However, RPBV did not appreciably influence any cumulative growth performance measures liver abscess incidence or severity.

164 Effect of Processing Method of Hybrid rye on Growth Performance, Efficiency of Dietary net Energy Utilization, and Carcass Characteristics of Yearling Steers fed a Finishing Diet

Abstract Predominantly Angus steers were used in a 147-day randomized complete block design experiment (RCBD) to evaluate the effects of rye processing method on growth performance, feed efficiency, and carcass characteristics. Steers [n = 192, initial body weight (BW) = 410 ± 20.9 kg] were individually weighed and allotted to 1 of 24 pens (n = 8 steers/pen; 6 pens/treatment). Four treatments were used where hybrid rye grain (total ergot alkaloid concentration = 1,007 ppb, DM basis) was processed using three different methods [unprocessed (UP); dry-rolled (DR); or hammer-milled (HM)] fed at 17% of diet DM along with 43% dry-rolled corn (DRC) compared with a control diet containing 60% DRC on a DM basis (CON). Data were analyzed as an RCBD using the GLIMMIX procedure of SAS with treatment as the fixed effect and block (Pen location) as the random effect; pen was the experimental unit. No differences (P ≥ 0.44) were observed among treatments for live final BW or average daily gain (ADG). Dry matter intake (DMI) was greater for HM (12.27 kg) compared with CON and DR (11.84 and 11.48 kg, respectively) with DR having 4.9% less DMI compared with UP (P = 0.01; SEM = 0.200). UP and HM treatments tended to have 4.8% poorer G:F compared with CON and DR (P = 0.07). Dietary treatments did not affect carcass traits, percent empty body fatness (EBF), or final BW at 28% EBF (P ≥ 0.23). Distributions of USDA Quality or Yield grades were unaffected by treatment (P ≥ 0.23), nor was the incidence or severity of liver abscesses (P = 0.25). Estimated NEm and NEg values of the diet for UP (1.90 and 1.26 Mcal/kg, respectively) were reduced compared with CON and DR (1.98 and 1.32 Mcal/kg, respectively), with HM intermediate (P = 0.05, SEM = 0.033 and 0.029 for NEm and NEg, respectively). Net energy values for UP and HM rye were within 7% of current feeding standards when calculated using the substitution method. Rolling increased apparent ingredient NEg for rye by 30.1% compared with UP or HM rye. Processing rye grain by dry-rolling increased dietary net energy values and tended to improve gain efficiency compared with not processing or using a hammer mill. Rye grain can be partially substituted for DRC with negligible impact on growth performance or carcass measures.

312 Evaluation of Dietary Roughage Manipulation During the Feeding of Ractopamine Hydrochloride as a Method to Improve Ruminal Health and Control Liver Abscess Severity in Feedlot Steers

Abstract The objective of this study was to determine if additional roughage inclusion to feedlot steer finishing diets during the feeding of ractopamine hydrochloride (RH) is an effective method to improve rumen health and control liver abscess severity. Steers [n = 64; initial shrunk body weight (SBW) = 633 kg ± 35.1 kg] were sourced from an unrelated trial and remained in their previous study pens; pens (n = 8) were assigned to dietary treatment in a completely randomized design. All steers on trial were fed a common 7% [dry matter (DM) basis] roughage equivalent (RE) finishing diet composed of dry-rolled corn, dried distillers grains plus solubles, corn silage, and grass hay for the 58 d preceding study initiation. Steers were fitted with rumination tags to track daily rumination. Dietary treatments were CON: no diet change; and 12R: 5% (DM basis) RE addition to diet via grass hay during the feeding of RH. Steers were fed RH (300 mg/steer/d), finished on treatment diets for 28 d, and harvested at a commercial beef processor. Growth performance, efficiency of dietary net energy (NE) utilization, and continuous carcass data were analyzed with pen as the experimental unit (EU) and fixed effect of treatment. Minutes ruminating was analyzed as an analysis of covariance with individual animal as the EU, fixed effects of treatment, days on feed (DOF) and their interaction, and baseline minutes ruminating as a covariate in the model. Liver abscess prevalence, rumen health, and categorical carcass data were analyzed with the Fisher’s exact test to determine differences between treatments. No difference (P ≥ 0.19) was observed for final SBW, average daily gain, dry matter intake, feed conversion efficiency, dressing percentage, hot carcass weight, calculated yield grade, marbling score, 12th rib fat thickness, calculated empty body fat, observed dietary NE for maintenance and gain, observed-to-expected dietary NE for maintenance and gain, or distribution of liver abscess prevalence, ruminitis score, or USDA yield grade. Ribeye area tended (P = 0.10) to differ between treatments with 12R steers exhibiting a 3.5% larger ribeye. Distribution of USDA quality grade differed (P = 0.003) between treatments with 12R steers having 25% more carcasses grading USDA average choice or better. A treatment × DOF interaction (P = 0.045) was observed for minutes ruminating per day. Daily minutes ruminating was increased (P ≤ 0.05) for 12R on d 1, 2, and 20 and tended to be increased (P ≤ 0.10) for 12R on days 10, 13, 24, and 25. Inclusion of an additional 5% RE to finishing cattle diets during a 28 d RH feeding period can be a management strategy to decrease risk of digestive upsets without sacrificing growth performance or carcass quality.

41 Growth Performance and Carcass Characteristics of Beef-Sired Steers Born to Holstein Dams

Abstract The objective of this study was to compare feedlot growth performance and carcass characteristics of F1 beef × Holstein steers (n = 124) sired by commercially available Angus (n = 19 from 7 sires), Charolais (n = 79 from 3 sires), SimAngus (n = 16 from 3 sires), or Wagyu (n = 10 from 2 sires) bulls. Male calves born from May to August of 2021, were sourced from 8 Pennsylvania dairy herds. Steers were raised by a commercial calf grower until April of 2021 (10.5 ± 1.5 months of age). Steers were then moved to the PA Department of Agriculture’s Livestock Evaluation Center (LEC) and transitioned to a high-energy ration. Individual feed intake was monitored using the GrowSafe Feed Intake Monitoring System (Model 4000E, Vytelle, Calgary AB, Canada). Steers were slaughtered after 90, 118, or 153 days on feed at the LEC. Pulls were based on a combination of visual appraisal and body weight. Linear models of growth performance traits and carcass characteristics included the fixed effects of sire breed, herd of origin, and birthdate. Binomial models of USDA Quality Grades and Yield Grades included a fixed effect of sire breed. Angus-sired steers were heaviest at feedlot entry (P < 0.01) and were on feed for the fewest days (P < 0.01). Angus × Holstein steers were heavier at slaughter (P < 0.01) than SimAngus and Wagyu-sired steers. Wagyu-sired steers had the least dry matter intake (DMI), average daily gain (ADG), and carcass ADG (P < 0.01) when compared with progeny of other sire breeds. No differences in gain to feed intake (G:F(; P = 0.90), back-calculated carcass G:F (P = 0.62), net energy of metabolism (P = 0.70) and net energy of gain (P = 0.70), nor hip height at harvest (P = 0.14) were detected between sire breeds. Wagyu × Holstein carcasses were the lightest (P < 0.01) and had the least amount of backfat (P = 0.01). Dressing percentage tended to be least (P = 0.10) in Charolais × Holstein carcasses (60.5%) and greatest in SimAngus × Holstein carcasses (61.7%); carcasses from Angus and Wagyu-sired steers were intermediate and not different. About 84% of Angus × Holstein carcasses graded Choice while only 31% of SimAngus × Holstein carcasses graded Choice (P = 0.03). However, there were no differences in called marbling scores between sire breeds (P = 0.15). Charolais × Holstein tended to have the lowest proportion (4%) of Yield Grade 1 carcasses (P = 0.05). Angus-sired steers were on feed for the fewest days when compared with steers sired by other beef breeds. Wagyu × Holstein steers had reduced ADG, DMI, and subsequent carcass weight in comparison with compared steers of other sire breeds.