Meat quality responses to feeding distiller's grains to finishing Holstein steers.

Strip loins from two experiments were used to evaluate effects of feeding dry (DDG) or wet (WDG) distiller's grains on beef color, tenderness, and sensory traits of Holstein steers. In Exp. 1, conducted at the University of Illinois at Champaign-Urbana, dietary treatments consisted of a control whole corn-corn silage diet with soybean meal (SBM) or diets formulated with 12.5% DDG plus urea, 25% DDG, 25% WDG, 50% DDG, or 50% WDG (DM basis). In Exp. 2, conducted at Iowa State University, dietary treatments consisted of cracked corn-corn silage-hay diets with either SBM or urea (Urea) as the control diets, or diets formulated with 10, 20, or 40% DDG or WDG (DM basis). Within each study, strip loins from each of four steers (representing 45.7 and 66.6% of steers in Exp. 1 and 2, respectively) in four replicate pens per treatment were aged for 13 d at 4 degrees C for subsequent color, tenderness, and palatability evaluation. Color of steaks was measured objectively using a HunterLab Miniscan XE spectrophotometer and was subjectively evaluated by a trained panel. Tenderness was measured using the Warner-Bratzler shear force (WBSF) instrument on steaks cooked to 70 degrees C. For sensory evaluation, 95 consumers were recruited to evaluate tenderness, juiciness, and flavor of cooked steaks. In Exp. 1, steaks from steers fed 25% WDG had higher (P < 0.05) a* values after 138 h of simulated retail display than all other treatments, except for those from steers fed 12.5% DDG. In Exp. 2, a greater (P < 0.05) percentage of steaks from steers fed 40% DDG or 40% WDG were considered moderately undesirable during retail display (steaks that received a consumer acceptability score of 3 or less). There were no (P = 0.20 in Exp. 1, and P = 0.33 in Exp. 2) differences among treatments in Exp. 1 and Exp. 2 for WBSF (1.47 +/- 0.66 kg and 1.58 +/- 0.72 kg, respectively) or taste panel tenderness (5.7 +/- 0.30 and 6.2 +/- 0.22, respectively), beef flavor (6.0 +/- 0.23 and 6.2 +/- 0.22, respectively), and juiciness (5.6 +/- 0.31 and 5.8 +/- 0.23). Feeding distiller's grains at up to 50% of the dietary DM did not affect tenderness or sensory traits, and seems to be a viable feed alternative without negatively impacting sensory attributes.

The effect of vitamin E supplementation on discoloration of injection-site lesions in retail cuts and the greening reaction observed in injection-site lesions in muscles of the chuck.

Concern has been raised about green discoloration of injection-site lesions in chuck muscles in modified-atmosphere packages. Objectives were: 1) to recreate green lesions, 2) to compare the severity of discoloration of injection-site lesions in chucks from carcasses of control or vitamin E-supplemented steers, and 3) to identify pigment(s) responsible for discoloration via in vitro color reactions. In Exp. 1, 23 steers (BW = 415 kg; 37 d before harvest) were injected with one of 12 pharmaceuticals, following label directions for route and dose, with the exception of a 5-mL maximum dose, to identify a product that could result in discoloration. Two vaccines (Products A and B) resulted in greening. In Exp. 2, 50 steers were injected (i.m.) with Product A and assigned to the control or vitamin E (1,000 IU/steer daily for 60 d) group. After retail display, 80 and 72% of steaks from the control and treatment groups, respectively, were discolored. Although vitamin E did not reduce (P = 0.53) greening, there was a trend (P = 0.10) toward delay discoloration of lesions from the treatment group. In Phase I of Exp. 3, pigments extracted from green lesions obtained from Exp. 2 were compared with solutions, exposed to a high partial pressure of oxygen (ppO), of myoglobin (Mb), copper sulfate, hydrogen peroxide (H2O2), vaccine, and aluminum hydroxide either alone or in combination. In Phase II of Exp. 3, solutions of two or more of Mb, Cu, sodium sulfide, sodium sulfite, sodium sulfate (Na2SO4), and H2O2 were made at pH 7.2 or 5.5 and exposed to low or high ppO. Normal muscle tissue displayed a 3.2 and 56.7% decrease in absorbance/microg of protein as wavelength changed from 654 to 656 nm and 656 to 658 nm, respectively. Pigments from control and treatment group green tissue displayed a 164.5 and 621.3% increase, respectively, in absorbance/microg of protein as wavelength changed from 654 to 656 nm. As wavelength changed from 656 to 658 nm, the absorbance/microg of protein for control and treatment group lesions decreased by 75 and 109%, respectively. The Mb+Cu+Na2SO4 solution, at pH 5.5 and high ppO, exhibited similar absorbance trends as green lesions indicating that greening may result from a Mb, Cu, and Na2SO4 interaction. Results indicated that greening varies with pharmaceuticals and oxidation of tissue cannot be controlled with vitamin E supplementation. Research on the causative agents of green discoloration, with an emphasis on compounds containing sulfate or Cu, is needed.

Effectiveness of the SmartMV prototype BeefCam System to sort beef carcasses into expected palatability groups.

This study was conducted to determine the effectiveness of the SmartMV prototype BeefCam Video Imaging System (prototype BeefCam) for classifying beef carcasses into palatability ("certified" or "not certified" as palatable) groups. Carcasses (n = 769) were selected from four beef-packing plants to represent three USDA quality grade groups (Top Choice, TC; Low Choice, LC; and Select, SE). Following chilling, a prototype BeefCam image of the longissimus muscle was obtained for each carcass. Strip loins were collected from the left side of each carcass and aged for 10 d; Warner-Bratzler shear force (WBSF; n = 769) values and consumer panel ratings (hedonic, end-anchored, 9-point ratings for overall like/dislike; n = 500 carcasses) were obtained for cooked steaks. Using information from the images, two regression models were developed to predict the first principal component of WBSF and consumer panel ratings for sorting carcasses based on expected eating quality. Model I used only prototype BeefCam output, whereas Model II used prototype BeefCam output and a coded value for quality grade group. For both models, carcasses with a predicted value of less than 0.0 were certified as producing palatable beef Additional carcasses (n = 292) were evaluated at a fifth and separate packing plant by prototype BeefCam to validate Models I and II. A strip loin was collected from each carcass and WBSF was measured after 14 d of aging. The percentages of validation carcasses that generated tough (WBSF > or = 4.5 kg) steaks were 6.5,5.8,10.7, and 7.9% for, TC, LC, SE, and all carcasses, respectively. Use of Model I certified 51.9, 47.6, 43.8, and 47.3% of TC, LC, SE, and all carcasses, respectively. Of the carcasses certified by use of Model I, 0.0,0.0, 4.1, and 1.4% of TC, LC, SE, and all carcasses, respectively, generated tough steaks. Use of Model II certified 59.7, 47.6, 25.0, and 42.1% of TC, LC, SE, and all carcasses, respectively. Of the carcasses certified by use of Model II, 2.2, 0.0, 3.6, and 1.6% of TC, LC, SE, and all carcasses, respectively, generated tough steaks. For both models, the frequency of carcasses that produced tough steaks in the certified group was lower (P < 0.05) for all validation carcasses sampled compared with that of the original carcass population. Based on the decrease in the frequency of carcasses that produced tough steaks, further development of a commercial BeefCam system is warranted.

Frequencies of injection-site lesions in muscles from rounds of dairy and beef cow carcasses.

The frequency of injection-site lesions in muscles from top sirloins and rounds in fed cattle carcasses is well documented; this study characterizes the frequency and severity of lesions in muscles from rounds of beef and dairy cow carcasses. Audits were conducted in 1998, 1999, and 2000 on 3190 rounds from cow carcasses. Outside round muscles were cut into 1.25-cm slices to characterize lesions. In 1998, 31% of beef rounds and 60% of dairy rounds had an injection-site lesion. Frequency of lesions in beef rounds significantly declined 5 percentage points between 1998 and 1999 and 6 percentage points between 1999 and 2000. The frequency of lesions in dairy rounds significantly declined 9 percentage points between 1998 and 1999 and 16 percentage points between 1999 and 2000. Frequencies of injection-site lesions in muscles of beef rounds were significantly lower than those in muscles of dairy rounds in all 3 yr. Injection-site lesions were most common between the hooks and pins of the hindquarter of beef cattle and between the pins and hocks of the hindquarter of dairy cattle. Clear lesions and woody calluses exceeded 89% and occurred more frequently than did other kinds of lesions in muscles of beef and dairy rounds in 1998, 1999, and 2000 audits. Of all injection-site lesions, between 3 and 5% were cystic in muscles of beef rounds, similar to the 2 to 4% of cystic lesions found in muscles of dairy rounds. Although yearly data indicate trends in declining frequencies of injection-site lesions, the need remains for educational programs and continued improvements in beef quality assurance practices among both beef and dairy producers.

Incidence of injection-site lesions in beef top sirloin butts.

Damaged beef muscle tissue resulting from intramuscular injections of animal-health products represents a "quality control" problem and an economic loss to the beef industry. Fifteen individual and sequential national audits of injection-site lesions in beef top sirloin butts have been conducted at the steak provisioner/cutting level between November 1995 and July 2000. The national incidence of injection-site lesions in top sirloin butts (n = 240,080) decreased (P < 0.05) between November 1995 (11.4%) and July 2000 (2.1%). From November 1995 to July 1997, mean weight per injection-site lesion, across all lesion classes, increased (P < 0.05) from 192.5 g to 435.8 g, respectively; mean weight per lesion subsequently decreased (P < 0.05) to 249.8 g in July 2000 but was still heavier (P < 0.05) than in November 1995. Results of these audits suggest that producers have changed injection practices. These changes have likely been in response to educational efforts, such as those made by National Cattlemen's Beef Association and through state beef quality assurance programs. Analyses of results for lesion classes, partitioning lesions according to chronological stages of the healing process, suggested that the majority of lesions were induced at times that coincide with cow-calf, stocker, or early finishing-period stages of cattle production.

Effects of three levels of alpha-tocopheryl acetate supplementation to feedlot cattle on performance of beef cuts during retail display.

Retail packages (n = 288; 24 of each product in each treatment group) of inside round steaks, T-bone steaks (strip loin and tenderloin), top sirloin steaks, and ground beef were used to evaluate effects of dietary supplementation of vitamin E to cattle on product performance during retail display. Products from control animals and cattle fed 500 IU x animal(-1) x d(-1) or 1,000 IU x animal(-1) x d(-1) were evaluated. Except for ground beef, dietary supplementation of vitamin E increased (P < 0.05) alpha-tocopherol concentrations in beef muscle from cattle fed 1,000 IU x animal(-1) x d(-1). Although not all differences were statistically significant, retail display-life was greater for all steaks from cattle fed 1,000 IU x animal(-1) x d(-1) than for those from control cattle. Ten percent of the inside round and tenderloin steaks from cattle fed 1,000 IU x animal(-1) x d(-1) had mean overall appearance scores of 3 ("moderately undesirable") at 72 to 78 h and 54 to 60 h, respectively, whereas 10% of the inside round and tenderloin steaks from control cattle had mean overall appearance scores of 3 at 54 to 60 h and 42 to 48 h, respectively. Each of the retail cuts in this study (irrespective of the amount of alpha-tocopheryl acetate that was fed to the animal that generated it) was categorized as "high," "medium," or "low," based on the alpha-tocopherol concentration in the primal cut or ground beef batch from which it originated. Retail cuts in the medium a-tocopherol concentration category had increased retail display life of 4.0 h for ground beef (P < 0.05) over those in the low alpha-tocopherol category. Retail cuts in the high alpha-tocopherol concentration category had increased retail display life of 10.7 h for inside round steaks and 4.0 h for ground beef (P < 0.05) over those in the medium concentration category. Vitamin E supplementation of cattle at 1,000 IU x animal(-1) x d(-1) for at least 100 d can be used to increase retail caselife and to improve the overall color acceptability of steaks and ground beef products. Although far from a perfect relationship, these data strongly suggest that increasing the alpha-tocopherol concentration in a beef cut will increase its retail case life.

National market cow and bull beef quality audit-1999: a survey of producer-related defects in market cows and bulls.

The 1999 National Market Cow and Bull Beef Quality Audit comprised face-to-face interviews with industry representatives (n = 49); in-plant evaluations of cattle in holding pens (n = 3,969), carcasses on harvest floors (n = 5,679), and in carcass coolers (n = 4,378); and a strategy workshop. Face-to-face interviews suggested that the beef industry was most frequently concerned about the presence of antibiotic residues in carcasses, presence of lead shot in carcasses, and price discovery for carcasses following excessive trimming of bruises and testing due to arthritic joints, pathogens, or antibiotic residues. Although live animal evaluations determined that 73.4% of beef cows, 60.8% of dairy cows, 63.7% of beef bulls, and 70.9% of dairy bulls did not exhibit evidence of lameness, losses due to lameness were greater (P < 0.05) than in the 1994 National Non-Fed Beef Quality Audit. In-plant audits revealed that 88.9, 10.3, and 88.2% of cow carcasses and 18.9, 21.2, and 52.9% of bull carcasses had inadequate muscling, arthritic joints, and at least 1 bruise, respectively, all of which resulted in greater (P < 0.05) losses than the same defects in 1994. Audits revealed that 88.9% of cow carcasses and 18.9% of bull carcasses were lightly muscled, resulting in greater (P < 0.05) losses for cow carcasses, and similar (P > 0.05) losses for bull carcasses, than the same defect in the 1994 audit. Also, 14.5 and 30.8% of cow carcasses and 6.9 and 5.9% of bull carcasses had excess external fat and yellow-colored external fat, respectively, which was an improvement (P < 0.05) over 1994 results. In aggregate, 24.1, 19.2, 7.2, 6.7, 9.5, and 1.1% of livers, tripe, hearts, heads, tongues, and whole cattle or carcasses, respectively, were condemned and 60.6, 2.4, and 46.5% of cattle had hide damage from latent defects, insect damage, and brands, respectively. Condemnation rates were generally lower (P < 0.05), but tongue condemnations and frequency of branded hides were higher (P < 0.05) than in 1994. Producers should promote value in cows and bulls by managing to minimize quality defects, monitoring health and condition, and marketing in a timely manner. Using these techniques, producers might have recaptured $13.82, $27.50, and $27.50, respectively, for each cow or bull harvested in 1999.

Implant strategies during feeding: impact on carcass grades and consumer acceptability.

Anabolic growth promotants influence beef grade factors and Warner-Bratzler shear force of steaks. No study has assessed the consumer acceptability of beef derived from implanted cattle. This study determined beef carcass grades and consumer acceptability for cooked beef from unimplanted (control) cattle and from cattle implanted with one of seven different implant strategies (initial implant/implant at 59 d = Encore & Component T-S/no implant, Ralgro/Synovex Plus, Ralgro/Revalor-S, Revalor-S/Revalor-S, Revalor-S/no implant, no implant/Synovex Plus, and Synovex Plus/no implant). British crossbred steers (n = 448) were allocated randomly into one of eight pens for each of the control and seven treatment groups. Carcass quality and yield grade (n = 403) and Warner-Bratzler shear force (n = 298) data were collected by trained personnel. Twenty steaks per control or treatment group were selected randomly for use in consumer sensory evaluation. Steaks were evaluated by consumers for overall like, tenderness like, tenderness level, flavor like, flavor intensity, and juiciness level using 9-point, end-anchored hedonic scales. Control carcasses had smaller (P < .05) longissimus muscle areas than carcasses in all treatment groups except those receiving Encore & Component T S/no implant, Ralgro/Synovex Plus, or Revalor S/no implant. Control carcasses had higher (P < .05) marbling scores than carcasses in all treatment groups except those receiving Ralgro/Revalor-S or Encore & Component T-S/no implant. Steaks from control steers had lower (P < .05) Warner-Bratzler shear force values than steaks from steers given Revalor-S/no implant. Consumer ratings for tenderness like and tenderness level were influenced (P < .05) by implant strategy. Effects of implant strategy on overall like, flavor like, and flavor intensity approached significance (P = .07 to .09). Consumers rated steaks from unimplanted steers as more tender (tenderness level; P < .05) than steaks from all treatment groups except that involving Encore & Component T-S/no implant. Consumers rated steaks from unimplanted steers as more desirable (P < .05) for tenderness like than steaks from all treatments except those involving Encore & Component T-S/no implant or Revalor-S/no implant. Although use of implants in this study resulted in heavier hot carcass weights and larger ribeyes, some of the implant strategies reduced consumer preference of tenderness of steaks.

Effects of a unique application of electrical stimulation on tenderness, color, and quality attributes of the beef longissimus muscle.

This study evaluated effects of four uniquely applied beef carcass electrical stimulation (ES) treatments on USDA grade factors, muscle color, subprimal purge loss, cooked steak weight loss, and cooked steak tenderness. One side of each (n = 284) beef carcass was subjected to ES using one of four treatments (medium voltage for medium duration, MVMD; medium voltage for long duration, MVLD; high voltage for medium duration, HVMD; or high voltage for long duration, HVLD) and was compared to its corresponding non-ES control side. Electrical stimulation of beef sides was applied focusing on middle meats while preventing severe contraction of the round and chuck. From matched (ES and control) sides of 120 carcasses (10 each of Select, low Choice, and upper two-thirds of Choice in each of the four ES treatments), longissimus steaks (2.5 cm thick) were cooked and used for Warner-Bratzler shear force (WBS) analysis. Mean marbling scores (n = 284) for stimulated sides did not differ (P = .923) from those for control sides within ES treatment classes. Mean values for CIE L*, a*, and b* of lean color (n = 284) were higher (P < .05) for MVMD, MVLD, HVMD, and HVLD treated sides than for the respective control sides. When WBS values for steaks were adjusted to an equal visual degree of doneness, WBS values (n = 120) were lower (P < .05) for ES treated sides than for control sides for all four types of ES application treatments. Treatment responses were not influenced by USDA Quality Grade group. For those carcasses for which the control sides had WBS values greater than 4.5 kg, matching sides treated with MVMD, MVLD, HVMD, or HVLD had WBS values less than 4.5 kg 50, 88, 60, and 75% of the time, respectively. Mean cooked steak weight loss (n = 120), adjusted to an equal visual degree of doneness, and mean purge loss (n = 24) did not differ with ES treatment.