ObjectivesThe National Beef Quality Audit (NBQA)– 2016 instrument-grading assessment evaluated beef carcass traits over the course of a year from selected beef processors. The objective of this study was to determine frequency distributions of ribeye areas within USDA quality grades. Materials and MethodsThere were 4,544,635 beef carcasses represented in the NBQA–2016 instrument-grading assessment. These data were collected from 18 federally-inspected processing facilities owned by 5 major beef processors over a 12-mo period (January 2016 through December 2016). Information was recorded during 1 wk of production each month at each facility. A variety of carcass trait information was collected at each facility including hot carcass weight, ribeye area, and marbling score, from which quality grades were determined. In an effort to create uniform ribeye area categories, ribeye area measurements were rounded down to a whole figure (i.e., 13.0 to 13.9 in² rounded down to 13.0 in²) and then were converted to metric units after data analysis. ResultsAnalysis of the NBQA–2016 data revealed ribeye area frequency within USDA Prime, Choice, and Select quality grades reached its highest rate in the 83.9 cm² category, at 23.2, 22.4, and 20.1%, respectively. Of the 183,856 Prime carcasses evaluated, over two-thirds (67.7%) were recorded in the 4 smallest ribeye area categories, ranging from 64.5 cm² to 83.9 cm². For Select, 30.1% of the 960,157 carcasses possessed a ribeye area falling into 1 of the 4 largest categories between 96.8 cm² to 116.1 cm² compared to 24.1% Choice and 12.7% Prime. Additionally, evaluation of all 4484,420 carcasses from NBQA–2016 found that the majority of each quality grade, 62.4% Prime, 60.4% Choice, and 55.2% Select, yielded a ribeye area between 77.4 cm² and 90.3 cm². The mean ribeye area for all carcasses recorded was 88.9 cm², an increase in area from 88.45 cm² in the NBQA–2011. When considering USDA Certified Programs, ribeye area mean was within qualification parameters with 86.2% of carcasses evaluated meeting the ribeye area specification for Certified Angus Beef (not considering additional specification requirements). Notably for Prime, 92.5% of the carcasses met the ribeye area specifications for Certified Angus Beef. Moreover, the NBQA–2016 demonstrated an increase in hot carcass weight when compared to the previous study, at 393.6 kg and 371.28 kg, for NBQA–2016 and NBQA–2011, respectively. The correlation between ribeye area and hot carcass weight (r = 0.40) is indicative of a moderate, positive relationship, meaning a heavier carcass weight tends to result in a greater ribeye area. ConclusionThese results show the relationship between ribeye area and USDA quality grade that can be considered in future industry specification and/or sorting programs.

ObjectivesThe National Beef Quality Audit (NBQA) has been an integral information source for the beef industry for almost 3 decades. The NBQA–2016 surveyed both fed steers/heifers and market cows/bulls, and one objective was to compare condemnation rates for by-products between these 2 sectors. With this knowledge, strategies may be developed to reduce economic losses related to by-product condemnations.Materials and MethodsData were collected with the assistance of USDA-Food Safety and Inspection Service personnel. By-products from fed steers/heifers (livers, lungs, and viscera: n = 24,940; heads and tongues: n = 26,657) and from market cows/bulls (livers, lungs, and viscera: n = 4800; heads and tongues: n = 5720) were assessed for condemnations, and when available, reasons for condemnation were recorded. Data were analyzed using JMP Pro, Version 12.0.1 (SAS Inst. Inc., Cary, NC). Frequency distributions were evaluated using the distribution function of JMP for condemnation traits assessed. Tests of hypotheses regarding differences in prevalence of by-product condemnations between NBQA-2016 fed steers/heifers and market cows/bulls were conducted at P = 0.05 using Chi-square analysis.ResultsBy-product condemnations tended to be higher for market cows/bulls than fed steers/heifers for livers, lungs, viscera, heads, and tongues. For liver condemnations, market cows/bulls had a higher incidence (P < 0.0001) of flukes (3.2% versus 1.1%), abscesses (20.7% versus 17.8%), and total condemnations (44.6% versus 30.8%), whereas fed steers/heifers had a greater incidence (P < 0.0001) of contamination (10.1% versus 7.8%). However, both cattle populations showed a high frequency of liver condemnations, with nearly a third (fed steers/heifers) and half (market cows/bulls) of all livers being condemned. Lung condemnations, primarily a result of contamination, were higher (P < 0.0001) for market cows/bulls (23.1%) versus fed steers/heifers (18.2%). Additionally, lung pneumonia was not different for the 2 groups of cattle (P = 0.6264). With conventional feedlot confinement, a higher incidence of lung pneumonia might be expected in fed steers/heifers, however, advanced chronological age of market cows/bulls may contribute to similar (7.4% versus 7.6%) pneumonia rates in this population. Viscera condemnations for abscesses were higher (P < 0.0001) in market cows/bulls (5.1 versus 2.8%), whereas fed steers/heifers had a greater incidence of viscera contamination (13.4 versus 10.1%; P < 0.0001). For both head and tongue by-products, market cows/bulls had a higher incidence (P < 0.0001) of condemnations than the fed steers/heifers.ConclusionOverall, rates of by-product condemnations identified during the NBQA-2016 were higher than anticipated. These condemnations can be a substantial and unnecessary economic loss to the industry, especially because they are often a result of inputs at the feedyard or management practices at the ranch. Producers and processors should consider ways to reduce condemnation of these valuable by-products.

The instrument grading assessment portion of the National Beef Quality Audit (NBQA) - 2016 allows the unique opportunity to evaluate beef carcass traits over the course of a year. One week of instrument grading data was collected each month from 5 beef processing corporations encompassing 18 facilities from January 2016 through December 2016 ( = 4,544,635 carcasses). Mean USDA yield grade (YG) was 3.1 with 1.37 cm fat thickness (FT), 88.9 cm LM area, 393.6 kg HCW, and 2.1% KPH. Frequency distribution of USDA YG was 9.5% YG 1, 34.6% YG 2, 38.8% YG 3, 14.6% YG 4, and 2.5% YG 5. Increases in HCW and FT since the NBQA-2011 were major contributors to differences in mean YG and the (numerically) increased frequency of YG 3, 4, and 5 carcasses found in the current audit. Mean marbling score was Small, and the distribution of USDA quality grades was 4.2% Prime, 71.4% Choice, 21.7% Select, and 2.7% other. Frequency of carcasses grading Prime on Monday (6.43%) was numerically higher than the average frequency of carcasses grading Prime overall (4.2%). Monthly HCW means were 397.6 kg in January, 397.2 kg in February, 396.5 kg in March, 389.3 kg in April, 384.8 kg in May, 385.0 kg in June, 386.1 kg in July, 394.1 kg in August, 399.1 kg in September, 403.9 kg in October, 406.5 kg in November, and 401.9 kg in December. Monthly mean marbling scores were Small in January, Small in February, Small in March, Small in April, Small in May, Small in June, Small in July, Small in August, Small in September, Small in October, Small in November, and Small in December. Both mean HCW and mean marbling score declined in the months of May and June. The month with the greatest numerical frequency of dark cutters was October (0.74%). Comparison of overall data from in-plant carcass and instrument grading assessments revealed close alignment of information, especially for YG (3.1 for in-plant assessment versus 3.1 for instrument grading) and marbling (Small for in-plant assessment versus Small for instrument grading). These findings allow the beef industry access to the greatest volume of beef value-determining characteristics for the U.S. fed steer and heifer population than ever reported, resulting in potentially more precise targeting of future quality and consistency efforts.

The National Beef Quality Audit-2016 marks the fourth iteration in a series assessing the quality of live beef and dairy cows and bulls and their carcass counterparts. The objective was to determine the incidence of producer-related defects, and report cattle and carcass traits associated with producer management. Conducted from March through December of 2016, trailers (n = 154), live animals (n = 5,470), hide-on carcasses (n = 5,278), and hide-off hot carcasses (n = 5,510) were surveyed in 18 commercial packing facilities throughout the United States. Cattle were allowed 2.3 m2 of trailer space on average during transit indicating some haulers are adhering to industry handling guidelines for trailer space requirements. Of the mixed gender loads arriving at processing facilities, cows and bulls were not segregated on 64.4% of the trailers surveyed. When assessed for mobility, the greatest majority of cattle surveyed were sound. Since the inception of the quality audit series, beef cows have shown substantial improvements in muscle. Today over 90.0% of dairy cows are too light muscled. The mean body condition score for beef animals was 4.7 and for dairy cows and bulls was 2.6 and 3.3, respectively. Dairy cattle were lighter muscled, yet fatter than the dairy cattle surveyed in 2007. Of cattle surveyed, most did not have horns, nor any visible live animal defects. Unbranded hides were observed on 77.3% of cattle. Carcass bruising was seen on 64.1% of cow carcasses and 42.9% of bull carcasses. However, over half of all bruises were identified to only be minor in severity. Nearly all cattle (98.4%) were free of visible injection-site lesions. Current results suggest improvements have been made in cattle and meat quality in the cow and bull sector. Furthermore, the results provide guidance for continued educational and research efforts for improving market cow and bull beef quality.

The National Beef Quality Audit-2016 (NBQA-2016) was conducted to assess current transportation, mobility, and quality characteristics of U.S. fed steers and heifers. Data were collected at 17 beef processing facilities between March and November 2016. About 8,000 live cattle were evaluated for transportation and mobility, and about 25,000 carcasses were evaluated on the slaughter floor. Cattle were in transit to the slaughter facility for a mean duration of 2.7 h from a mean distance of 218.5 km using trailers with dimensions ranging from 17.84 m(2) to 59.09 m(2). Area allotted per animal averaged 1.13 m(2) and ranged from 0.85 m(2) to 2.28 m(2). A total of 96.8% of cattle received a mobility score of 1 (walks easily, no apparent lameness). Identification types (35.1% had multiple) were lot visual tags (61.5%), individual tags (55.0%), electronic tags (16.9%), metal-clip tags (9.2%), bar-coded tags (0.05%), wattles (0.01%), and other (2.6%). Cattle were black-hided (57.8%), Holstein (20.4%), red-hided (10.5%), yellow-hided (4.8%), gray-hided (2.9%), brown-hided (1.3%), and white-hided (1.1%). Unbranded hides were observed on 74.3% of cattle; 18.6% had brands located on the butt, 6.3% on the side, and 1.3% on the shoulder (values exceed 100% due to multiple brands). For hide-on carcasses, 37.7% displayed no mud or manure; specific locations for mud or manure were legs (40.8%), belly (33.0%), tail region (15.5%), side (6.8%), and top-line (3.9%). Cattle without horns represented 83.3% of the sample, and cattle that did have horns measured: < 2.54 cm (5.5%), 2.54 to 12.7 cm (8.3%), and > 12.7 cm (2.9%). Carcasses without bruises represented 61.1% of those sampled, whereas 28.2% had 1, 8.2% had 2, 2.1% had 3, and 0.3% had 4 bruises. Of those carcasses with a bruise, the bruise was located on the loin (29.7%), round (27.8%), chuck (16.4%), rib (14.4%), and brisket/plate/flank (11.6%). Frequencies of offal condemnations were livers (30.8%), lungs (18.2%), viscera (16.3%), hearts (11.1%), heads (2.7%), and tongues (2.0%). Compared to NBQA-2011, fewer cattle were identified for traceability, fewer were black-hided, a greater number were Holstein cattle, more with no brand and no horns, fewer without bruises, more liver, lung, and viscera condemnations, and fewer heads and tongues were condemned. The NBQA remains an influential survey for the U.S. beef industry to provide benchmarks and strategic plans for continued improvement of beef quality and consistency.

The National Beef Quality Audit (NBQA)-2016 used in-plant cooler assessments to benchmark the current status of the fed steer and heifer beef industry in the United States. In-plant cooler assessments ( = 9,106 carcasses) were conducted at 30 facilities, where approximately 10% of a single day's production were evaluated for USDA quality grade (QG) and yield grade (YG) factors. Frequencies of evaluated traits were 66.5% steer and 33.4% heifer sex classes and 82.9% native, 15.9% dairy-type, and 1.2% estimated breed types. Mean USDA YG factors were 1.42 cm for adjusted fat thickness, 89.5 cm for LM area, 390.3 kg for HCW, and 1.9% for KPH. Mean USDA YG was 3.1, with a frequency distribution of 9.6% YG 1, 36.7% YG 2, 39.2% YG 3, 12.0% YG 4, and 2.5% YG 5. Mean USDA QG traits were Small for marbling score, A for overall maturity, A55 for lean maturity, and A for skeletal maturity. Mean USDA QG was Select with a frequency distribution of QG of 3.8% Prime, 67.3% Choice, 23.2% Select, and 5.6% lower score. Lower score included dark cutter (1.9%), blood splash (0.1%), and hard bone, which are USDA overall maturity scores of C or older (1.8%). Marbling score distributions were 0.85% Slightly Abundant or greater, 7.63% Moderate, 23.54% Modest, 39.63% Small, 23.62% Slight, and 0.83% Traces or less. Carcasses that were Choice or Select and USDA YG 2 or 3 accounted for 70.7% of the carcasses evaluated. Compared with the previous NBQA, we found a numerical increase in mean USDA YG, USDA QG, adjusted fat thickness, HCW, LM area, and marbling score with an increase in dairy-type carcasses and percentage of carcasses grading USDA Prime and Choice as well as frequency of USDA YG 4 and 5. The findings from this study will be used by all segments of the industry to understand and improve the quality of fed steer and heifer beef that is being produced.

A 141 d finishing study using 108 crossbred yearling steers (Initial BW = 415 ± 1.13 kg) evaluated whole (WC, 5.5 mm) or dry-rolled (RC, 2.8 mm) corn in diets with 20 or 40% grass hay (GH). The study was a 2 × 2 factorial, with WC or RC as one factor and 20 or 40% GH as another. Steers were stratified by BW and randomly assigned to pen (n = 12) and 1 of 4 treatments (n = 3 pens/treatment). Diets were formulated to meet or exceed NRC recommendations and included modified corn distillers grains (25% DM basis) and an ionophore/vitamin/mineral supplement (2%, DM basis). Initial BW were recorded on d 0 and every 28 d till harvest. No corn type × forage level interactions were detected (P ≥ 0.21). Initial BW were similar (P = 0.96) among treatments, and for WC and RC (P ≥ 0.47) across all 5 weight periods (WP). Overall ADG was similar (P ≥ 0.25) across all WP, except d 56, steers on RC gained more compared to WC (P = 0.03). Overall DMI was similar for WC and RC (P ≥ 0.42). While overall G:F tended (P = 0.09) to favor RC, all interim periods had similar (P ≥ 0.29) G:F with the exception of d 56, when RC was lower than WC (P = 0.003). Carcass attributes were similar (P ≥ 0.11) for WC and RC. BW was similar (P ≥ 0.69) among GH treatments, at d 0 and through d 56; however greater (P ≤ 0.03) for 20% GH at each subsequent period after d 56. ADG was greatest for 20% GH during periods 1 − 3 and overall. While DMI was similar (P ≥ 0.20) among GH treatments across all periods and for the whole 141 d trial. G:F followed a similar pattern to ADG. The 20% GH cattle used less feed to gain a kg of body weight for periods 1 − 3 and overall, compared with 40% GH (P ≤ 0.03). Marbling score, LM area, BF and DP were similar among GH levels (P ≥ 0.16). HCW and YG tended (P = 0.06) to be greater for 20% GH. Results indicate corn type and GH level did not interact and feeding RC slightly improved feed efficiency over WC. 20% GH diets had higher calculated energy values which did translate into improved ADG and feed efficiency over the 40% GH diets.

Background: the relatively high concentration of polyunsaturated fatty acid in yellow corn may reduce the quality of pork fat, but feeding barley instead of yellow corn may increase pork quality. Objective: to determine the effects of feeding graded levels of barley on performance, carcass composition, and pork quality of finishing pigs. Methods: in experiment 1, diets containing 0, 20, 40, 60, or 80% barley were fed to pigs (initial BW: 67.9 kg) for 8 weeks. In experiment 2, a diet containing 60% barley was fed to pigs for 0, 2, 4, 6, or 8 weeks prior to slaughter. Results: feeding diets with increasing levels of barley resulted in a linear decrease in daily gain (p<0.01) and backfat thickness (p<0.01). Dressing percentage linearly decreased with length of barley feeding (p<0.05), but the concentration of saturated fatty acids in backfat increased (linear, p<0.05) the longer the barley diet was fed. Conclusion: there was no effect of barley on loin muscle quality and barley did not consistently change fat color or belly and bacon quality.

Summary Background: the relatively high concentration of polyunsaturated fatty acid in yellow corn may reduce the quality of pork fat, but feeding barley instead of yellow corn may increase pork quality. Objective: to determine the effects of feeding graded levels of barley on performance, carcass composition, and pork quality of finishing pigs. Methods: in experiment 1, diets containing 0, 20, 40, 60, or 80% barley were fed to pigs (initial BW: 67.9 kg) for 8 weeks. In experiment 2, a diet containing 60% barley was fed to pigs for 0, 2, 4, 6, or 8 weeks prior to slaughter. Results: feeding diets with increasing levels of barley resulted in a linear decrease in daily gain (p<0.01) and backfat thickness (p<0.01). Dressing percentage linearly decreased with length of barley feeding (p<0.05), but the concentration of saturated fatty acids in backfat increased (linear, p<0.05) the longer the barley diet was fed. Conclusion: there was no effect of barley on loin muscle quality and barley did not consistently change fat color or belly and bacon quality.

Differences in pre-harvest stress measurements and carcass characteristics between kosher and not-qualified-as-kosher cattle were evaluated. Finished heifers (n=157) were slaughtered by a shochet while held in an upright position using Glatt slaughter procedures. Stress measurements were collected prior to slaughter. Carcass data were collected, and 3.8-cm thick samples were taken from the loin at the 13th rib. Steaks from each sample were evaluated for mechanical tenderness and simulated retail display. Cattle with shorter times from gate to exsanguination and lower vocalization scores were more likely (P<0.01) to qualify as kosher. Kosher carcasses had larger (P=0.02) ribeye areas and higher (P<0.0001) Warner–Bratzler shear values. At each day of simulated retail display, kosher steaks had lower (P<0.05) L*, a*, and b* values. These data suggest that body composition and pre-harvest stress affect the likelihood of a beef animal qualifying as kosher and quality differences exist between kosher and non-kosher steaks.

The tenderness and palatability of retail and food service beef steaks from across the United States (12 cities for retail, 5 cities for food service) were evaluated using Warner-Bratzler shear (WBS) and consumer sensory panels. Subprimal postfabrication storage or aging times at retail establishments averaged 20.5 d with a range of 1 to 358 d, whereas postfabrication times at the food service level revealed an average time of 28.1 d with a range of 9 to 67 d. Approximately 64% of retail steaks were labeled with a packer/processor or store brand. For retail, top blade had among the lowest (P < 0.05) WBS values, whereas steaks from the round had the greatest (P < 0.05) values. There were no differences (P > 0.05) in WBS values between moist-heat and dry-heat cookery methods for the top round and bottom round steaks or between enhanced (contained salt or phosphate solution) or nonenhanced steaks. Food service top loin and rib eye steaks had the lowest (P < 0.05) WBS values compared with top sirloin steaks. Retail top blade steaks and food service top loin steaks received among the greatest (P < 0.05) consumer sensory panel ratings compared with the other steaks evaluated. Prime food service rib eye steaks received the greatest ratings (P < 0.05) for overall like, like tenderness, tenderness level, like juiciness, and juiciness level, whereas ungraded rib eye steaks received the lowest ratings (P < 0.05) for like tenderness and tenderness level. The WBS values for food service steaks were greater (P < 0.05) for the Select and ungraded groups compared with the Prime, Top Choice, and Low Choice groups. The WBS values and sensory ratings were comparable to the last survey, signifying that no recent or substantive changes in tenderness have occurred.

Two experiments were conducted to determine the effect of increasing field pea level in high-concentrate finishing cattle diets on beef palatability including Warner-Bratzler shear force (WBSF), sensory panel tenderness, juiciness, flavor, and off-flavor. In Exp. 1, 118 yearling heifers (417 ± 2.4 kg of initial BW) were assigned randomly to 1 of 4 treatments (0, 10, 20, or 30% dry-rolled field pea, DM basis; 4 pens/treatment), where field pea replaced dry-rolled and high-moisture corn. In Exp. 2, 143 beef steers (433 ± 19.1 kg of initial BW) were assigned randomly to 1 of 4 treatments (0, 10, 20, or 30% dry-rolled field pea, DM basis; 6 pens/treatment) where field pea replaced dry-rolled corn. In Exp. 1, field pea inclusion linearly decreased WBSF (P = 0.001) and linearly increased sensory taste panel tenderness (P = 0.002) and juiciness (P = 0.04) scores, whereas cook loss, flavor, and off-flavor scores were not affected by treatment (P ≥ 0.16). In Exp. 2, field pea inclusion did not affect WBSF, cook loss, or sensory taste panel scores for tenderness, juiciness, flavor, or off-flavor (P ≥ 0.19); however, there was a tendency for a decrease in calpastatin activity (P = 0.10) and a tendency for an increase in troponin-T degradation (P = 0.08) with increasing dietary field pea inclusion. These results indicate that dietary field pea does not negatively affect beef palatability traits. Additional research should focus on understanding the potential mechanism by which field pea inclusion may influence beef tenderness.

This survey consisted of data collected from 23 beef harvest plants to document transportation procedures, management practices, and health assessments of market beef and dairy cows and bulls (about n ≅ 7,000 animals). Gooseneck/bumper-pulled trailers were used more often to transport dairy cattle than beef cattle to market whereas tractor-trailers were used more often to transport beef cattle than dairy cattle. All loads (n = 103) met the American Meat Institute Foundation guidelines for spacing. Loads where more than 3% of the cattle slipped during unloading were observed in 27.3% of beef loads and 29.0% of the dairy loads. Beef loads had numerically greater usage of electrical prods (32.4%) versus dairy loads (15.4%) during unloading and were more likely to have a variety of driving aids used more aggressively on them. Fewer cattle had horns, brands, and mud/manure contamination on hides than in the previous survey in 1999. The predominant hide color for beef cows was black (44.2%) whereas the predominant color for dairy cows was the Holstein pattern (92.9%). Fewer cattle displayed evidence of bovine ocular neoplasia (2.9%) than in previous surveys in 1994 (8.5%) and 1999 (4.3%). Knots on live cattle were found less in the round (0.5%) and more in the shoulder region (4.6%) than in 1999 (1.4% and 0.4%, respectively). Dairy cows were more frequently lame in 2007 (48.7%) than 1999 (39.2%) whereas beef cows had numerically less lameness (16.3% vs. 26.6%, respectively). Most beef cows (62.3%) and dairy cows (68.9%) received midpoint body condition scores (3, 4, and 5 for beef; 2 and 3 for dairy). Beef cows had higher numerical percentages of no defects present (72.0%) versus dairy cows (63.0%) when evaluated for a variety of reproductive, health, or management conditions. Continued improvements in several key factors related to transportation, management, and health were observed in this survey, which could result in increased value in market beef and dairy cows and bulls.

Th e objective of this study was to investigate the eff ects of feeding strategy on cow feedlot performance, carcass traits and economics. Despite cows consuming less feed and lower labor costs, cows on self-fed diets had the highest feed cost of gain. Although self-fed diets can improve market cow quality, other low-cost alternatives require further investigation. Summary Forty-eight cull (market) cows were blocked by weight and body condition to investigate the eff ects of feeding strategy on feedlot performance, carcass traits and economics. Diets evaluated were (1) corn-mixed hay (HAY), (2) barley-barley silage (SILAGE) and (3) a self-fed ground diet using a controlled intake system (LIMIT). All diets were formulated to provide 60 megacalories per pound (Mcals/lb) of net energy for gain (NEg) and 11.5 percent crude protein (CP) using mixed hay, barley silage and a commercial supplement containing soy hulls as roughage sources for HAY, SILAGE and LIMIT, respectively.

Two hundred forty Angus crossbred steers were used to determine the influence of feeding various quantities of wet and dry distillers grains to finishing steers on carcass characteristics, meat quality, retail-case life of ground beef, and fatty acid profile of LM. Three replications of 5 dietary treatments were randomly applied to 15 pens in each of 2 yr. A finishing diet containing dry-rolled corn, soybean meal, and alfalfa hay was fed as the control diet. Wet distillers grains with solubles (DGS) or dry DGS was added to the finishing diets at either 20.0 or 40.0% of the dietary DM to replace all soybean meal and part of the cracked corn in treatment diets. Carcasses of steers fed DGS had greater (P < 0.05) fat thickness (1.47 vs. 1.28 cm), greater (P < 0.05) USDA yield grades (3.23 vs. 2.94), and smaller (P < 0.05) percentage of yield grades 1 and 2 (41.1 vs. 60.4%) than carcasses of steers fed the control diet. Longissimus muscle from steers fed dry DGS had greater (P < 0.05) ultimate pH values (5.52 vs. 5.49) than LM from steers fed wet DGS. Ground beef from steers fed DGS had greater (P < 0.05) concentrations of α-tocopherol (1.77 vs. 1.43 μg/g) than ground beef from steers fed the control diet. Ground beef from steers fed 40% DGS had greater (P < 0.05) thiobarbituric acid-reactive substances (2.84 vs. 2.13 mg/kg) on d 2 of retail display than ground beef from steers fed 20% DGS. Longissimus muscle of steers fed DGS had less (P < 0.05) C17:0 and more (P < 0.05) C18:0, C18:1t, C16:1c9, C18:2c9c12 (where t is trans and c is cis), and total PUFA than LM of steers fed the control diet. Feedlot steers fed DGS may need to be marketed earlier than normal to avoid excess external fat and carcasses with a greater numerical yield grade. These data suggest feeding DGS to finishing steers will have no adverse or beneficial effects on glycolytic variables (dark cutters), retail display life of ground beef, or meat tenderness. However, beef from cattle finished on diets containing DGS will likely have a greater proportion of PUFA and therefore may be more susceptible to oxidative rancidity.

Eighty Angus and Angus x Simmental steer calves were used in a completely random design to determine the effect of rate of BW gain during the backgrounding period on subsequent feedlot performance, carcass characteristics, Warner-Bratzler shear force (WBSF), and sensory analysis. Animals were stratified by BW and allotted randomly to 1 of 10 pens (5 pens/treatment). Dietary treatments were formulated for an ADG of 0.91 kg/d [low BW gain (LG), 1.06 Mcal of NE(g)/kg] diets and 1.25 kg/d [high BW gain (HG), 1.19 Mcal of NE(g)/kg]. Steers were fed 70 d during the growing period. The LG diet consisted of 52.5% barley silage, 39.0% whole shell corn, and 8.5% supplement, whereas the HG diet contained 43.9% barley silage, 47.4% whole shell corn, and 8.7% supplement (DM basis). Initial BW (226 kg) was not different (P = 0.70) between treatments. Steers fed the HG diet had increased ADG (1.67 vs. 1.40 kg/d; P < 0.001) compared with steers fed LG diet. Dry matter intake was greater (9.49 vs. 8.35 kg/d; P < 0.001) for steers fed the HG vs. LG diet. Total backgrounding cost ($/animal) was less (P < 0.001) for those steers fed LG diet compared with HG diet ($126.00 vs. $140.35, respectively); however, total cost per kilogram of BW gain was not different (P = 0.24; $0.485/kg of BW gain). After the backgrounding period, steers were fed a common finishing diet for 135 d. During the finishing period, LG steers had similar (P = 0.12; 10.73 vs. 10.35 kg/d) DMI compared with those fed HG diets; however, ADG was not different (1.55 kg; P = 0.72) among treatments. Hot carcass weight, marbling score, 12th-rib fat, LM area, and USDA yield grade were not different (P > 0.12) between treatments and averaged 363 kg, Sm(30), 1.33 cm, 83.8 cm(2), and 2.7, respectively. There were no differences (P = 0.77; 3.63 +/- 0.12 kg) in WBSF tenderness of rib-eye steaks. Percent cooking loss was increased in LG diets (P = 0.017). No differences were observed in consumer sensory analysis of tenderness, juiciness, and flavor intensity (P > or = 0.276; 5.43 +/- 0.12, 5.07 +/- 0.13, and 5.17 +/- 0.05, respectively). These data suggest that feeding steers diets that differ in energy concentration and result in ADG of 1.4 and 1.7 kg/d during the growing period results in minimal changes in subsequent finishing performance and does not affect meat quality.