Longissimus Muscle Steaks Research Articles

36 Productive and Physiological Responses of Feedlot Cattle Receiving Different Sources of Ca Salts of Fatty Acids in the Finishing Diet

Abstract This experiment compared productive and physiological responses in feedlot cattle receiving a finishing diet that included Ca salts of palm oil (CSPALM), or a blend of Ca salts of palm, cottonseed, and soybean oils (CSMIX). Ninety yearling steers were housed in 15 pens equipped with Calan-gate feeders (6 steers/pen). Steers within each pen were ranked by shrunk body weight (BW; 410 ± 3.3 kg) on d 0 and assigned to receive a total-mixed ration (TMR) containing (as-fed basis) 2% of CSMIX (n = 30), 2% of CSPALM (n = 30), or no supplemental fat (CON; n = 30). Individual TMR intake was evaluated weekly. Blood samples were collected on d 0, 28, 56, 119, and 147. Samples of the Longissimus muscle (LM) were collected on d 84 via needle biopsy. Upon slaughter on d 148, hot carcass weight (HCW) was recorded and used to determine final BW (63% dressing), whereas one LM steak sample (2.54 cm) was removed from the right side of each carcass. Steer ADG was greater (P = 0.02) for CSMIX compared with CSPALM and tended to be greater (P = 0.09) for CSMIX compared with CON. Feed efficiency was greater (P ≤ 0.05) for CSMIX compared with CSPALM and CON, and carcass LM area was less (P = 0.01) for CSPALM compared with CSMIX and CON. No treatment effects were detected (P ≥ 0.21) for TMR intake, final BW, and other carcass merit traits including marbling. Mean plasma cholesterol concentrations were greater (P < 0.01) in CSMIX and CSPALM compared with CON, and expression of adipocyte fatty acid binding protein in the LM was greater (P ≤ 0.04) in CSPALM compared with CSMIX and CON. No treatment effects were detected (P ≥ 0.15) for plasma concentrations of glucose, insulin, insulin-like growth factor I, and leptin, nor for other LM genes associated with marbling and muscle growth. Concentrations of total fatty acids (FA) in plasma and in LM steaks were greater (P < 0.01) in CSMIX compared with CSPALM and CON, and greater (P < 0.01) in the LM steaks of CSPALM steers compared with CON. Moreover, steers receiving CSMIX had greater (P < 0.01) concentrations of polyunsaturated and ω-6 FA in plasma samples and LM steaks compared with CSPALM and CON. Collectively, supplementing CSMIX improved performance traits and FA profile in the LM of feedlot steers, but the same responses were not observed when CSPALM was offered. The advantages noted from CSMIX supplementation appear to be resultant from the nutraceutical benefits of increased polyunsaturated ω-6 FA supply to the finishing diet.

PSV-A-6 Poor Maternal Nutrition During Gestation Decreases Shear Force and Alters Gene Expression Related to Fibrogenesis

Abstract To test the hypothesis that poor maternal nutrition during gestation would alter offspring muscle shear force and adipogenesis, fibrogenesis, and myogenesis mRNA expression, Dorset ewes (n=46) pregnant with twins were fed 100%, 60% or 140% of NRC requirements from d30±0.02 of gestation until parturition. Male offspring from CON (n=12), OVER (n=13), and RES (n=21) ewes were euthanized at d284±1.82 and longissimus muscle (LM) was harvested for shear force and gene expression. Vacuum-sealed LM steaks were aged for 10 d postmortem (4℃) and tenderness was measured using Warner-Bratzler shear force (WBSF) methodology. RNA was isolated from the LM to quantify mRNA expression of genes related to adipogenesis (fatty acid binding protein 4, CCAAT/enhancer-binding protein α, and peroxisome proliferator-activated receptor γ), fibrogenesis [collagen A1A (COLA1A), COL3A1, cystain-c, fibronectin (FN1), and lysyl oxidase (LOX)], and myogenesis [bone-morphogenic protein (BMP)-1, myostatin, myogenin, and myogenic differentiation 1). The WBSF decreased by 21% and 18% in OVER relative to CON (P=0.01) and RES (P=0.03), respectively, but CON and RES were not different (P=0.60). Expression of BMP1 was 1.5- and 1.8-fold greater in RES than OVER and CON, respectively (P≤0.03). Expression of FN1 was 1.6-fold greater in RES than OVER (P=0.02). Expression of COL1A1 was 2.2-fold greater in RES than CON (P=0.05) and was 1.6-fold greater in RES than OVER (P=0.07). Expression of LOX was decreased 37% in OVER compared with CON (P=0.04) and decreased 21% compared with RES (P=0.08). An effect of diet was not observed for other genes (P≥0.18). In summary, RES offspring had greater expression of genes related to fibrogenesis, but no observed difference in tenderness relative to CON. Over-feeding during gestation increased meat tenderness, which may be due to reduced collagen cross-linking by LOX.

Effect of ruminally protected arginine and lysine supplementation on serum amino acids, performance, and carcass traits of feedlot steers1.

One hundred twenty Angus × Simmental steers [322 ± 4.8 kg initial body weight (BW)] were blocked by BW and randomly allocated to 4 treatments arranged as a 2 × 2 factorial to evaluate the effects of supplemental arginine (none or 63 g/d of a 15.6% metabolizable arginine), supplemental lysine (none or 40 g/d of a 25% metabolizable lysine), and their interaction on performance and carcass composition of feedlot steers during a 170-d feeding period. The basal diet [dry matter (DM) basis] contained 52% dry-rolled corn, 22% dried distillers grains with solubles, 20% corn silage, and 6% vitamin-mineral supplement. Lysine balance was estimated to be -10.3 to -10.8 g for diets that did not contain supplemental lysine, and arginine supply was estimated to be +9.7 g for diets that did not contain supplemental arginine during period 1 (days 0 to 87). Lysine and arginine supplies met or exceeded requirements in period 2 (days 88 to 170). Rumen-protected arginine and lysine were top dressed daily until slaughter at a common BW (622 ± 5.5 kg). Data were analyzed using the MIXED procedure of SAS. Body weight, average daily gain, and DM intake were not affected (P ≥ 0.14) by arginine or lysine supplementation. However, lysine increased gain:feed (P = 0.05) during period 1. Lysine decreased serum urea nitrogen (P = 0.03) on day 87, increased (P = 0.01) longissimus muscle (LM) area, decreased (P ≤ 0.01) fat thickness and yield grade, and tended (P = 0.06) to increase moisture content of LM steaks. There tended to be an interaction for moisture content of steaks (P = 0.09), where arginine supplementation increased moisture content to a greater extent in steaks from cattle supplemented with lysine compared with steaks from cattle not fed supplemental lysine. Arginine tended to increase the proportion of Choice grade carcasses (P = 0.09) but did not change lipid content of steaks (P = 0.59). Arginine tended to decrease serum glutamate (P = 0.09) and lysine (P = 0.07) after 87 d of feeding. In conclusion, supplemental rumen-protected arginine and lysine did not improve performance, but lysine can increase carcass muscle and leanness, and although arginine did not increase lipid content of steaks, it may favorably shift carcasses to a greater quality grade.

Effects of production system and slaughter weight endpoint on growth performance, carcass traits, and beef quality from conventionally and naturally produced beef cattle

Glanc, D. L., Campbell, C. P., Cranfield, J., Swanson, K. C. and Mandell, I. B. 2015. Effects of production system and slaughter weight endpoint on growth performance, carcass traits, and beef quality from conventionally and naturally produced beef cattle. Can. J. Anim. Sci. 95: 37–47. Effects of production system and slaughter endpoint on performance, carcass traits, and beef quality were investigated in 64 Simmental cross steers (minimum 75% Continental breeding). Cattle were allocated to: (1) conventional production system based on use of implants and dietary ionophores or (2) natural production system in which no implants or ionophores were used. Within each production system, cattle were allocated for slaughter at 545 or 636 kg liveweight. Steers were fed an 85.5% concentrate diet based on high-moisture corn, soybean meal, and alfalfa silage. Average daily gain tended to be greater (P<0.06) in conventional production system cattle, while there was a trend (P<0.08) for production system by endpoint interactions for dry matter intake and gain to feed. Natural production system cattle tended to have greater (P<0.08) marbling and percent intramuscular fat (%IMF) with lower (P<0.09) longissimus shear force, while production system by endpoint interactions were present (P ≤ 0.03) for%IMF and carcass lean composition via rib dissection. At-home consumer evaluation of longissimus muscle steaks found tenderness, juiciness, flavour, and overall acceptability rankings were greater (P<0.01) for steaks slaughtered from heavier cattle (636 vs. 545 kg liveweight). Marketing cattle at lighter slaughter weights may have benefits for performance at the expense of eating quality.

Aging improves tenderness of longissimus muscle steaks from fed mature cows (2009)

Steaks from cows are tougher than those from young steers and heifers. This difference is often attributed to the increased cross-linkage of collagen in muscle of mature animals that is considered very stable and more resistant to postmortem degradation. Aging steaks from young steers and heifers is a common postmortem practice used to improve tenderness of steaks from the ribeye roll and strip loin. Improvement in tenderness because of aging has been attributed to enzymatic degradation of, primarily, the myofibrillar fraction of muscle and is most beneficial for low connective tissue muscles. Because muscles from mature cows have more collagen cross-linking, postmortem tenderization methods, such as blade tenderization and enzymatic tenderization, are often used to increase tenderness of steaks from mature cows. However, few studies have investigated the effect of aging on tenderness of longissimus muscle steaks from fed mature cows. Therefore, the objective of this study was to determine effects of aging on tenderness of longissimus steaks of fed mature cows from different management strategies.

Effects of skeletal separation method and postmortem ageing on carcass traits and shear force in cull cow beef

Sixty-six cull cow carcasses were subjected to skeletal separation methods for improving beef tenderness as evaluated using shear force. Forty-one carcasses were used to evaluate the effect on longissimus muscle shear force from skeletal separation at various sites including: (1) the 11th thoracic vertebra, (2) the 12th thoracic vertebra, and (3) the 6th thoracic and 5th lumbar vertebrae. Longissimus muscle steaks from the posterior and anterior loin and posterior rib were aged for 2, 7, 14, and 28 d. Twenty-five carcasses underwent skeletal separation processing in the round with severing of the ischium and the junction between 4th/5th sacral vertebrae. Semimembranosus, semitendinosus, biceps femoris, vastus lateralis, and rectus femoris muscles were processed into steaks and aged for 2, 7, 14, and 28 d. Skeletal separation techniques involving thoracic and lumbar vertebrae decreased (P < 0.04) shear force in the posterior rib and anterior loin but not in the posterior loin. Shear force continued to decrease (P < 0.01) as postmortem ageing duration increased. The semimembranosus was the only muscle in the round in which shear force decreased (P < 0.01) with skeletal separation. Postmortem ageing for at least 14 d decreased (P < 0.06) shear force in semimembranosus and vastus lateralis steaks while there were no further decreases in shear force after 7 d ageing for semitendinosus and rectus femoris steaks. Skeletal separation increased (P < 0.10) sarcomere length in all muscles studied. Skeletal separation techniques have the potential to improve tenderness in the longissimus and semimembranosus muscles, which may increase utilization of cull cow beef. Key words: Beef, cow, shear, tendercut, longissimus, round

Online prediction of beef tenderness using a computer vision system equipped with a BeefCam module1

Four experiments were conducted in two commercial packing plants to evaluate the effectiveness of a commercial online video image analysis (VIA) system (the Computer Vision System equipped with a BeefCam module [CVS BeefCam]) to predict tenderness of beef steaks using online measurements obtained at chain speeds. Longissimus muscle (LM) samples from the rib (Exp. 1, 2, and 4) or strip loin (Exp. 3) were obtained from each carcass and Warner-Bratzler shear force (WBSF) was measured after 14 d of aging. The CVS BeefCam output variable for LM area, adjusted for carcass weight (cm2/kg), was correlated (P < 0.05) with WBSF values in all experiments. The CVS BeefCam lean color measurements, a* and b*, were effective (P < 0.05) in all experiments for segregating carcasses into groups that produced LM steaks differing in WBSF values. Fat color measurements by CVS BeefCam were usually ineffective for segregating carcasses into groups differing in WBSF values; however, in Exp. 4, fat b* identified a group of carcasses that produced tough LM steaks. Quality grade factors accounted for 3, 18, 21, and 0% of the variation in WBSF among steaks in Exp. 1 (n = 399), 2 (n = 195), 3 (n = 304), and 4 (n = 184), respectively, whereas CVS BeefCam output variables accounted for 17, 30, 19, and 6% of the variation in WBSF among steaks in Exp. 1, 2, 3, and 4, respectively. A multiple linear regression equation developed with data from Exp. 2 accurately classified carcasses in Exp. 1 and 4 and thereby may be useful for decreasing the likelihood that a consumer would encounter a tough (WBSF > 4.5 kg) LM steak in a group classified as "tender" by CVS BeefCam compared with an unsorted population. Online measurements of beef carcasses by use of CVS BeefCam were useful for predicting the tenderness of beef LM steaks, and sorting carcasses using these measurements could aid in producing groups of beef carcasses with more uniform LM steak tenderness.

Shear gradient in longissimus steaks1

Boneless top loin subprimals (n = 320) from Slight and Small marbled carcasses were fabricated into 2.54-cm thick steaks to determine core location effects on tenderness. In Exp. 1, top loins were aged to 7 d before steaks were cut and cooked to an internal temperature of 71°C. After cooking, a maximum of 15 1.27-cm diameter cores were removed and sheared with a Warner-Bratzler shear force (WBSF) device. There was not a marbling score × core location interaction (P = 0.36). However, there was a main effect of core location (P < 0.01). Cores from the medial, middle, and lateral portion of the longissimus muscle (LM) aged for 7 d differed, with less resistance (P < 0.05) in the medial than the lateral end. Also, there was an effect of marbling score on WBSF, with Small-marbled steaks having lower (P < 0.02) WBSF values than Slight-marbled steaks. In a second experiment, steaks were removed from the middle of the top loin subprimals and aged an additional 7 d to produce 14-d aged steaks. Shear values decreased (P < 0.05) from Exp. 1 to 2 for all core locations. Neither the main effect of marbling score nor the core location × marbling score interaction was significant (P > 0.40); however, the same lateral to medial gradient in WBSF values was discovered again in Exp. 2. Both experiments indicated there were regions of WBSF values that differed (P < 0.05) across the cross section of the LM producing a shear-force/tenderness gradient, with the most medial cores having the lowest WBSF values in both experiments independent of marbling score. Regression analyses indicated the middle and center portions of LM steaks tended to have the most predictive capacity of average WBSF. Because of the variability in tenderness caused by location within the LM, care should be exercised when selecting sampling areas for the measurements of tenderness using the WBSF measure.

Shear gradient in longissimus steaks.

Boneless top loin subprimals (n = 320) from Slight and Small marbled carcasses were fabricated into 2.54-cm thick steaks to determine core location effects on tenderness. In Exp. 1, top loins were aged to 7 d before steaks were cut and cooked to an internal temperature of 71 degrees C. After cooking, a maximum of 15 1.27-cm diameter cores were removed and sheared with a Warner-Bratzler shear force (WBSF) device. There was not a marbling score x core location interaction (P = 0.36). However, there was a main effect of core location (P < 0.01). Cores from the medial, middle, and lateral portion of the longissimus muscle (LM) aged for 7 d differed, with less resistance (P < 0.05) in the medial than the lateral end. Also, there was an effect of marbling score on WBSF, with Small-marbled steaks having lower (P < 0.02) WBSF values than Slight-marbled steaks. In a second experiment, steaks were removed from the middle of the top loin subprimals and aged an additional 7 d to produce 14-d aged steaks. Shear values decreased (P < 0.05) from Exp. 1 to 2 for all core locations. Neither the main effect of marbling score nor the core location x marbling score interaction was significant (P > 0.40); however, the same lateral to medial gradient in WBSF values was discovered again in Exp. 2. Both experiments indicated there were regions of WBSF values that differed (P < 0.05) across the cross section of the LM producing a shear-force/tenderness gradient, with the most medial cores having the lowest WBSF values in both experiments independent of marbling score. Regression analyses indicated the middle and center portions of LM steaks tended to have the most predictive capacity of average WBSF. Because of the variability in tenderness caused by location within the LM, care should be exercised when selecting sampling areas for the measurements of tenderness using the WBSF measure.

Seasonal variation in venison quality of mature, farmed red deer stags in New Zealand.

Two studies involving 20 red deer (Cervus elaphus) stags were conducted to determine the effects of season on venison quality. In each study, five sexually mature red deer stags were slaughtered immediately preceding the rut (autumn) and five were slaughtered after the rut. Stags slaughtered postrut had lower carcass weights (25 to 30%) than those slaughtered prerut. Average bodywall thickness measurements above the 12th rib (an indicator of fat thickness) were approximately 31 mm prerut compared with 3 to 7 mm postrut. Individual muscles and retail cuts (which included subcutaneous and intermuscular fat) were heavier in prerut carcasses. There were significant decreases in intramuscular fat in both the longissimus muscle and the semimembranosus muscle. Postrut longissimus muscle steaks appeared brighter and(or) fresher than the other groups; color acceptability was negatively correlated (P less than .05) with fat content. Prerut streaks from both muscles were more tender than postrut steaks from those muscles. Overall desirability and tenderness were highly correlated (r = .94 and .82 for longissimus muscle and semimembranosus muscle, respectively).

FACTORS RELATED TO LONGISSIMUS TENDERNESS AMONG ALTERNATE METHODS OF LEAN BEEF PRODUCTION

ABSTRACTA 23 factorial arrangement of treatments comparing bull versus steer, Angus versus Limousin, and zeranol implanted versus nonimplanted controls was used as a data source for this trial. Bulls had less intramuscular lipid and more total collagen than steers. Limousin had less intramuscular lipid, shorter sarcomere lengths and a higher percentage of fast‐twitch glycolytic fibers than Angus cattle. Limousin and implanted cattle had more rapid postmortem temperature declines. Chemical, physical and histological traits as well as yield and quality grade traits were used in correlation procedures to examine their relationship with sensory panel tenderness and Warner‐Bratzler shear force values of longissimus muscle steaks. The results of this trial indicate that postmortem muscle temperature decline plays a role in longissimus palatability and must be considered in the production of leaner beef.

THE MEASUREMENT OF SHEAR FORCE BY CORE LOCATION IN LONGISSIMUS DORSI BEEF STEAKS FROM FOUR TENDERNESS GROUPS1

ABSTRACTSixty‐four longissimus muscle steaks obtained from carcasses of Bos indicus or Bos taurus cattle were used to evaluate shear force requirements from the dorsal to lateral portion of the steak. Steaks were assigned to one of four tenderness groups based on preliminary analysis of shear force requirements of adjacent steaks used in the study. Six dorsal to lateral core positions were incorporated into the test procedures. Shear force requirements of cores of steaks in very tender and tender groups tended (P&gt;0.05) to decrease from the dorsal to lateral position. The increase in shear values from dorsal to lateral was dramatic (P&lt;0.01) in the tough and very tough groups. It appears that overall shear value influences the variation in shear values within the muscle. Location effects of tenderness within the longissimus muscle could be useful in future studies of the physical/biochemical effectors of tenderness.

Flavor, Color, and Other Characteristics of Beef Longissimus Muscle Heated to Seven Internal Temperatures Between 55° and 85° C

ABSTRACTBeef longissimus muscle steaks were broiled or roasted to 7 internal temperatures. Mouth‐filling‐blend and browned flavor increased, whereas bloody‐serumy, metallic, and sour flavors and juiciness decreased with increased internal temperature. Roasted muscles had flavor characteristics more like muscle cooked to lower internal temperatures than broiled. Protein denaturation, as indicated by differential scanning calorimetry, appeared to be mostly complete after muscle samples were heated to 80 ° C. Visual color change occurred between 55° and 65° C, between 65° and 75° C, and between 75° and 80° C. HunterLab a values decreased and reflectance readings at 547 nm increased significantly between 75° and 80° C. Instron shear and compression and pH values did not vary significantly.

Effects of Sex Condition, Genotype, Diet and Carcass Electrical Stimulation on the Collagen Content and Palatability of Two Bovine Muscles

Longissimus muscle steaks and semimembranosus roasts were obtained for observations of collagen and sensory characteristics from carcasses of intact or castrated male Angus or Simmental cattle that were fed either a low- or high-energy density diet. Right sides of carcasses were electrically stimulated (ES). Data were expressed at a constant percentage of rib fat. Steaks and roasts were observed to be equal in shear force requirement. Steaks obtained from intact males were less (P<.05) tender than steaks from castrated males. Although not statistically significant, intact males tended to possess lean with greater (P>.05) quantities of collagen that was less (P>.05) soluble. No differences were observed between breed groups for sensory characteristics. Meat from cattle produced on the low-energy diet was more (P<.01) tender and tended (P>.05) to possess less sensory-panel-perceived and chemically extracted (P<.05) collagen. Total collagen content of the lean was not highly associated with subjective or objective measures of meat textural properties. Variation in percentage of soluble collagen was moderately associated with sensory-panel tenderness, perceived connective tissue and ease of fragmentation. Data suggest that solubility of connective tissue rather than total amount of connective tissue is more highly associated with sensory characteristics. Electrical stimulation of carcasses had no appreciable effect on observed carcass lean muscle color, texture or sensory characteristics.

Cholesterol Content of Raw and Cooked Beef Longissimus Muscles with Different Degrees of Marbling

ABSTRACTThe relationships of marbling level (eight levels from “Moderately Abundant” to “Practically Devoid”) and cooking to cholesterol content of beef longissimus muscle steaks were studied. Only raw steaks with “Practically Devoid” marbling contained significantly less cholesterol (wet basis) than did raw steaks with any of the other seven marbling scores. However, steaks cooked to an internal temperature of 60° or 75°C showed no significant differences in cholesterol content among any of the eight marbling groups. The cholesterol content of cooked steaks was 22–48% higher than that of raw steaks when cooked to 60°C and 38–65% higher when cooked to 75°C; cooking reduced the weight of each steak, thereby increasing the cholesterol content of the steak expressed as a percentage of the cooked weight.