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1.
Carcass (n = 568) and longissimus thoracis palatability (n = 460) traits from F1 steers obtained from mating Hereford (H), Angus (A), and U.S. Meat Animal Research Center (MARC) III cows to H, A, Norwegian Red (NR), Swedish Red and White (RW), Friesian (F), or Wagyu (W) sires were compared. Data were adjusted to constant age (471 d), carcass weight (356 kg), fat thickness (1.0 cm), percentage of fat trim (24%), and marbling (Small35) end points. For Warner-Bratzler shear force and trained sensory panel traits, data were obtained on longissimus thoracis steaks stored at 2 degrees C for 14 d postmortem. The following comparisons were from the age-constant end point. Carcasses from H- and A-sired steers (377 and 374 kg, respectively) were the heaviest (P < 0.05) and carcasses from W-sired steers (334 kg) were the lightest (P < 0.05). A greater (P < 0.05) percentage of carcasses from A- and W-sired steers graded USDA Choice (88 and 85%, respectively) than carcasses from other sire breeds (52 to 71%). Adjusted fat thickness for carcasses from A-sired steers (1.3 cm) was highest (P < 0.05), followed by H-sired steers (1.1 cm) and W- and F-sired steers (0.9 cm); NR- and RW-sired steers (0.8 cm) had the lowest (P < 0.05) adjusted fat thickness. Longissimus thoracis area was not different (P > 0.05) among sire breeds (mean = 80.6 cm2). Carcass yield of boneless, totally trimmed retail product was least (P < 0.05) for A-sired steers (60.1%), intermediate for H-sired steers (61.5%), and similar (P > 0.05) for all other sire breeds (62.5 to 62.8%). Longissimus thoracis steaks from carcasses of A- (3.7 kg) and W-sired (3.7 kg) steers had lower (P < 0.05) shear force values than longissimus thoracis steaks from other sire breeds (4.1 to 4.2 kg). Trained sensory panel tenderness, juiciness, or beef flavor intensity ratings for longissimus thoracis steaks did not differ (P > 0.05) among the sire breeds. Sire breed comparisons were affected by adjusting data to other end points. Heritability estimates for various carcass, yield, and palatability traits ranged from very low (h2 = 0.06 for percentage of kidney, pelvic, and heart fat) to relatively high (h2 = 0.71 for percentage of retail product yield). Relative to the other sire breeds, W-sired steers had the highest percentage of USDA Choice, Yield grade 1 and 2 carcasses, but their carcasses were the lightest.  相似文献   

2.
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3.
The objective of this experiment was to provide a current evaluation of the seven most prominent beef breeds in the United States and to determine the relative changes that have occurred in these breeds since they were evaluated with samples of sires born 25 to 30 yr earlier. Carcass (n = 649), yield (n = 569), and longissimus thoracis palatability (n = 569) traits from F(1) steers obtained from mating Hereford, Angus, and MARC III cows to Hereford (H), Angus (A), Red Angus (RA), Charolais (C), Limousin (L), Simmental (S), or Gelbvieh (G) sires were compared. Data were adjusted to constant age (445 d), carcass weight (363 kg), fat thickness (1.1 cm), fat trim percent (25%), and marbling (Small(35)) endpoints. For Warner-Bratzler shear force and trained sensory panel traits, data were obtained on LM from steaks stored at 2 degrees C for 14 d postmortem. The following comparisons were from the age-constant endpoint. Carcasses from L-, G-, and H-sired steers (361, 363, and 364 kg, respectively) were lighter (P < 0.05) than carcasses from steers from all other sire breeds. Adjusted fat thickness for carcasses from A-, RA-, and H-sired steers (1.5, 1.4, and 1.3 cm, respectively) was higher (P < 0.05) than for carcasses from steers from all other sire breeds (0.9 cm). Longissimus muscle areas were largest (P < 0.05) for carcasses from L-, C-, S-, and G-sired steers (89.9, 88.7, 87.6, and 86.5 cm(2), respectively) and smallest for carcasses from H- and RA-sired steers (79.5 and 78.4 cm(2)). A greater (P < 0.05) percentage of carcasses from RA- and A-sired steers graded USDA Choice (90 and 88%, respectively) than from carcasses from other sire breeds (57 to 66%). Carcass yield of boneless, totally trimmed retail product was least (P < 0.05) for RA- and A-sired steers (59.1 and 59.2%, respectively) and greatest (P < 0.05) for G, L-, C-, and S-sired steers (63.0 to 63.8%). Longissimus muscle from carcasses of A-sired steers (4.0 kg) had lower (P < 0.05) Warner-Bratzler shear force values than LM from carcasses of G- and C-sired steers (4.5 to 4.3 kg, respectively). Trained sensory panel tenderness and beef flavor intensity ratings for LM did not differ (P < 0.05) among the sire breeds. Continental European breeds (C, L, S, and G) were still leaner, more heavily muscled, and had higher-yielding carcasses than did British breeds (H, A, and RA), with less marbling than A or RA, although British breeds have caught up in growth rate.  相似文献   

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5.
Two hundred beef carcasses were randomly selected by dental classification (zero, two, four, six, or eight permanent incisors) from a population of 11,136 carcasses harvested by a large commercial beef processor. Warner-Bratzler shear force and trained sensory panel evaluations of longissimus thoracis steaks as well as cooking and carcass traits were evaluated for differences among dental classes. No differences in Warner-Bratzler shear force (P = 0.60), sensory panel evaluations (P = 0.64) for tenderness, or percentage of total cooking loss (P = 0.73) were found among the five dental classes. Longissimus muscle color, USDA marbling score, hot carcass weight, adjusted fat thickness, longissimus muscle area, and USDA yield grade did not differ among the five dental classes. A significant dental classification x sex interaction indicated that heifers advanced in skeletal and overall maturity at a much faster rate than steers. An increase of intramuscular fat was associated (P < 0.05) with decreased shear force (r = -0.31), whereas darkening of the lean (r = 0.16), advancing lean maturity (r = 0.21), and increased evaporative cooking loss (r = 0.39) were associated (P < 0.05) with increased shear force values. Warner-Bratzler shear force measurements were not related to sensory panel overall tenderness scores. Carcass traits accounted for a relatively small proportion of the variation in tenderness of longissimus steaks, and dental classification was not related to tenderness.  相似文献   

6.
The objectives of this experiment were to determine 1) whether end point temperature interacts with tenderness to affect Warner-Bratzler shear force of beef longissimus and 2) if so, what impact that interaction would have on tenderness classification. Warner-Bratzler shear force was determined on longissimus thoracis cooked to either 60, 70, or 80 degrees C after 3 and 14 d of aging from carcasses of 100 steers and heifers. Warner-Bratzler shear force values (3- and 14-d aged steaks pooled) for steaks cooked to 70 degrees C were used to create five tenderness classes. The interaction of tenderness class and end point temperature was significant (P < .05). The increase in Warner-Bratzler shear force as end point temperature increased was greater (P < .05) for less-tender longissimus than more-tender longissimus (Tenderness Class 5 = 5.1, 7.2, and 8.5 kg and Tenderness Class 1 = 2.4, 3.1, and 3.7 kg, respectively, for 60, 70, and 80 degrees C). The slopes of the regressions of Warner-Bratzler shear force of longissimus cooked to 60 or 80 degrees C against Warner-Bratzler shear force of longissimus cooked to 70 degrees C were different (P < .05), providing additional evidence for this interaction. Correlations of Warner-Bratzler shear force of longissimus cooked to 60 or 80 degrees C with Warner-Bratzler shear force of longissimus cooked to 70 degrees C were .90 and .86, respectively. One effect of the interaction of tenderness with end point temperature on tenderness classification was to increase (P < .01) the advantage in shear force of a "Tender" class of beef over "Commodity" beef as end point temperature increased (.24 vs .42 vs .60 kg at 14 d for 60, 70, and 80 degrees C, respectively). When aged 14 d and cooked to 80 degrees C, "Commodity" steaks were six times more likely (P < .01) than "Tender" steaks to have shear force values > or = 5 kg (24 vs 4%). The end point temperature used to conduct tenderness classification did not affect classification accuracy, as long as the criterion for "Tender" was adjusted accordingly. However, cooking steaks to a greater end point temperature than was used for classification may reduce classification accuracy. The beef industry could alleviate the detrimental effects on palatability of consumers cooking beef to elevated degrees of doneness by identifying and marketing "Tender" longissimus.  相似文献   

7.
The objective of this study was to compare carcass characteristics of a newly introduced breed, the Waguli (Wagyu x Tuli), with the carcass characteristics of the Brahman breed. Brahman cattle are used extensively in the Southwest of the United States because of their tolerance to adverse environmental conditions. However, Brahman carcasses are discounted according to the height of their humps because of meat tenderness issues. The Waguli was developed in an attempt to obtain a breed that retained the heat tolerance of the Brahman but had meat quality attributes similar to the Wagyu. Twenty-four animals were used. Six steers from each breed were fed a 94% concentrate diet and 6 steers from each breed were fed an 86% concentrate diet. Eight steers, 2 from each group, were harvested after 128 d, after 142 d, and after 156 d on feed. Waguli steers had larger LM, greater backfat thickness, greater marbling scores, and greater quality grades than the Brahman steers (P < 0.05). The Japanese Wagyu breed is well known for its highly marbled and tender meat, and these traits are also present in the Waguli. The Waguli had significantly lower Warner-Bratzler shear force values than the Brahman steers after 7 and 10 d of postmortem aging (P < 0.05); this difference decreased after 14 d postmortem (P = 0.2), when tenderness of the slower aging Brahman had increased to acceptable levels. Toughness of the Brahman has been associated with high levels of calpastatin in Brahman muscle, and the Waguli LM had significantly less calpastatin activity (P = 0.02) at 0 h postmortem than the Brahman LM. At 0-h postmortem, the total LM calpain activity did not differ between the Brahman and Waguli (P = 0.57). Neither diet nor days on feed had any significant effect on the 0-h postmortem calpain or at 0-h postmortem calpastatin activity, nor an effect on Warner-Bratzler shear-force values. In conclusion, LM muscle from the Waguli steers had a high degree of marbling, lower shear force values, and low calpastatin activity, all of which are related to more tender meat.  相似文献   

8.
Carcasses of 342 steers of known genetic backgrounds from four fundamentally different growth types were developed either on pasture or feedlot regimens to study differences in carcass traits. Growth types were large framed-late maturing (LL), intermediate framed-intermediate maturing (II), intermediate framed-early maturing (IE), and small framed-early maturing (SE). Five calves from each growth type were assigned to each regimen in each year of a 9-yr study. Eighteen steers were removed from the study because of accident or illness. Data collected were preslaughter shrunk BW (SBW); hot carcass weight (HCW); chilled carcass weight (CCW); dressing percentage (DRESS); fat thickness at the 12th and 13th-rib interface (FAT); percentage kidney, pelvic, and heart fat (KPH); longissimus muscle area (LMA); marbling score (MARB); quality grade (QG); and yield grade (YG). Differences in carcass traits reflected genetic differences among growth types. The LL steers had heavier BW, HCW, and CCW and larger LMA (P < .05) than steers of other growth types, regardless of development regimen. Among pasture-developed steer carcasses, IE and SE steers had higher (P < .05) MARB and QG than either LL or II steers. Carcasses of large framed-late maturing steers had the lowest (P < .05) MARB and QG of the growth types. Carcasses of the II, IE, and SE steers had a higher (P < .05) numerical value for YG than carcasses of the LL steers. Among the carcasses of the feedlot-developed steers, IE and SE steers had the highest (P < .05) MARB and QG. Carcasses from the IE and SE steers were fatter (P < .05) than those from LL or II steers. Carcasses of the LL steers had the lowest percentage of KPH of growth types developed in the feedlot. No difference was observed in KPH for carcasses of II, IE, and SE steers. The LL steer carcasses had the lowest numerical value for YG of all growth types. These data indicate that variation existed among carcass traits for the four growth types and that carcass traits influenced by fatness were greater and more attainable in the feedlot-developed steers using current methods of evaluation.  相似文献   

9.
Effects of repetitive use of anabolic implants on beef carcass quality, tenderness, and consumer ratings for palatability were investigated using crossbred steer calves (n = 550). Steers from five ranches were randomly allocated to one of 10 different lifetime implant strategies or to a nonimplanted control group. Cattle were implanted at some or all of five phases of production (branding, weaning, backgrounding, feedlot entry, or reimplant time). Carcasses from the control group had higher (P < 0.05) marbling scores than carcasses from steers in all other treatment groups. Implanting steers at branding, weaning, or backgrounding vs. not implanting steers at these production stages did not affect (P > 0.05) marbling scores. Steers implanted twice during their lifetime produced carcasses with higher (P < 0.05) marbling scores than did steers receiving a total of four or five implants. Steaks obtained from carcasses in the control group had lower (P < 0.05) shear force values and were rated by consumers as more desirable (P < 0.05) for tenderness like/dislike than steaks obtained from carcasses in all other treatment groups. Implanting steers at branding or weaning production stages did not affect (P > 0.05) steak shear force values, consumer ratings for like/dislike of steak tenderness, or percentage of consumers rating overall eating quality of steaks as satisfactory. Implanting steers at backgrounding vs. not implanting steers at this production stage increased (P < 0.05) steak shear force values, but did not influence (P > 0.05) consumer ratings for like/dislike of steak tenderness or percentage of consumers rating overall eating quality of steaks as satisfactory. Steaks from nonimplanted steers were rated as more desirable (P < 0.05) for overall eating quality than steaks from steers implanted two, three, four, or five times. Use of implants increased (P < 0.05) average daily gain by 11.8 to 20.5% from weaning to harvest compared with nonimplanted controls. Implant strategies increased (P < 0.05) hot carcass weight of steers by 8.9 to 13.8% compared with the control group. Use of implants also increased (P < 0.05) longissimus muscle area and decreased (P < 0.05) estimated percentages of kidney/pelvic/heart fat, but did not affect (P > 0.05) dressing percentage or adjusted fat thickness. Our findings suggest that beef quality, palatability, and production characteristics are influenced by lifetime implant protocols.  相似文献   

10.
The objective of this study was to benchmark carcasses and muscles from commercially identified fed (animals that were perceived to have been fed an increased plane of nutrition before slaughter) and nonfed cull beef and dairy cows and A-maturity, USDA Select steers, so that the muscles could be identified from cull cow carcasses that may be used to fill a void of intermediately priced beef steaks. Carcass characteristics were measured at 24 h postmortem for 75 carcasses from 5 populations consisting of cull beef cows commercially identified as fed (B-F, n = 15); cull beef cows commercially identified as nonfed (B-NF, n = 15); cull dairy cows commercially identified as fed (D-F, n = 15); cull dairy cows commercially identified as nonfed (D-NF, n = 15); and A-maturity, USDA Select grade steers (SEL, n = 15). Nine muscles were excised from each carcass [m. infraspinatus, m. triceps brachii (lateral and long heads), m. teres major, m. longissimus dorsi (also termed LM), m. psoas major, m. gluteus medius, m. rectus femoris, and m. tensor fasciae latae] and subjected to Warner-Bratzler shear force testing and objective sensory panel evaluation after 14 d of postmortem aging. Carcass characteristics differed (P < 0.05) among the 5 commercially identified slaughter groups for the traits of lean maturity, bone maturity, muscle score, HCW, fat color, subjective lean color, marbling, ribeye area, 12th-rib fat thickness, and preliminary yield grade. Carcasses from commercially identified, fed cull cows exhibited more (P < 0.01) weight in carcass lean than did commercially identified, nonfed cull cows. There was a group x muscle interaction (P = 0.02) for Warner-Bratzler shear force. Warner-Bratzler shear force and sensory overall tenderness values demonstrates that muscles from the SEL group were the most tender (P < 0.01), whereas muscles from the B-NF group were the least tender (P < 0.01). Sensory, beef flavor intensity was similar (P > 0.20) among cull cow carcass groups and more intense (P < 0.01) than the SEL carcass group. Muscles from the SEL group exhibited less (P < 0.01) detectable off-flavor than the cull cow carcass groups, whereas the B-NF group exhibited the most (P < 0.01) detectable off-flavor. Although carcass and muscle quality from commercially identified, fed, cull beef and dairy cows was not similar to A-maturity, USDA Select beef, they did show improvements when compared with nonfed, cull, beef and dairy cow carcasses and muscles.  相似文献   

11.
The objective of this study was to determine the extent of variation in, and relationships among, biochemical and palatability traits within and among 11 major beef muscles. Longissimus thoracis et lumborum (LD), psoas major (PM), gluteus medius (GM), semimembranosus (SM), adductor (AD), biceps femoris (BF), semitendinosus (ST), rectus femoris (RF), triceps brachii (TB), infraspinatus (IS), and supraspinatus (SS) from one side of 31 Charolais x MARC III steer carcasses were vacuum-packaged, stored at 2 degrees C until 14 d postmortem, and then frozen at -30 degrees C. The 2.54-cm-thick steaks were obtained from two or three locations within muscles in order to assess biochemical traits and Warner-Bratzler shear force, and from near the center for sensory trait evaluation. The PM was most tender and was followed by IS in both shear force and tenderness rating (P < 0.05). The other muscles were not ranked the same by shear force and tenderness rating. The BF had the lowest (P < 0.05) tenderness rating. The PM, GM, and LD had lower (P < 0.05) collagen concentration (2.7 to 4.5 mg/g muscle) than muscles from the chuck and round (5.9 to 9.0 mg/g), except for the AD (4.9 mg/g). Desmin proteolysis was highest (P < 0.05) for BF and LD (60.7 and 60.1% degraded), and was lowest (P < 0.05) for PM (20.2%). The PM, TB, IS, RF, and ST had relatively long sarcomere lengths (> 2.1 microm), whereas the GM had the shortest (P < 0.05) sarcomere length (1.7 microm). Cooking loss was lowest (P < 0.05) for BF (18.7%) and was followed by LD and IS (20.7%); it was highest (P < 0.05) for ST (27.4%). Across all muscles, tenderness rating was highly correlated (r > 0.60) with shear force, connective tissue rating, sarcomere length, and collagen content. Within a muscle, correlations among all traits were generally highest in LD and lowest in AD. Within muscle, location effects were detected (P < 0.05) for shear force (PM, ST, BF, SM, and RF), sarcomere length (PM, ST, BF, LD, SS, IS, SM, and RF), collagen concentration (PM, BF, SS, IS, SM. AD, TB, and RF), desmin degradation (PM, GM, BF, SM, AD, and, RF), and cooking loss (all muscles except SS and AD). There is a large amount of variation within and among muscles for tenderness traits and tenderness-related biochemical traits. These results increase our understanding of the sources of variation in tenderness in different muscles and provide a basis for the development of muscle-specific strategies for improving the quality and value of muscles.  相似文献   

12.
The objective of this study was to determine the effect of sampling methodology on the relationship between longissimus tenderness and measures of biochemical meat traits. Sampling methodology included measurements of sarcomere length, collagen concentration, and postmortem desmin proteolysis on raw samples and measurements of these same traits on the same cooked meat used for shear force measurement. Twenty crossbred steers and 20 crossbred barrows were used for these studies. The beef longissimus thoracis were vacuum-packaged, stored at 2 degrees C until 14 d postmortem, then frozen and stored at -30 degrees C. The pork longissimus thoracis et lumborum were vacuum-packaged, stored at 2 degrees C until 7 d postmortem, then frozen and stored at -30 degrees C. Trained sensory panel tenderness rating ranged from 3.1 to 7.6 for beef and 4.1 to 7.4 for pork. The coefficient of variation was lower for sarcomere length than for all other traits. Simple correlation coefficients between measurements on raw and cooked samples were 0.58 (beef) and 0.11 (pork) for sarcomere length, 0.66 (beef) and 0.59 (pork) for collagen, and 0.74 (beef) and 0.76 (pork) for desmin degradation. Simple correlation coefficients between biochemical traits and measures of tenderness (Warner-Bratzler shear force and trained sensory tenderness rating) were higher or not different for cooked compared to raw samples. Correlation coefficients between biochemical traits and tenderness rating were 0.38 (raw) and 0.22 (cooked) for sarcomere length, -0.12 (raw) and -0.45 (cooked) for collagen, and 0.48 (raw) and 0.80 (cooked) for desmin degradation in beef longissimus and 0.14 (raw) and 0.15 (cooked) for sarcomere length, -0.38 (raw) and -0.33 (cooked) for collagen, and 0.53 (raw) and 0.67 (cooked) for desmin degradation in pork longissimus. The coefficients of determination for explaining variation in tenderness rating using sarcomere length, collagen concentration, and desmin degradation for raw and cooked samples were 0.43 and 0.73 (beef) and 0.48 and 0.57 (pork), respectively. This study indicates that measurements of biochemical traits on the same cooked meat as used for shear force determination account for more of the variation in measures of tenderness than biochemical measurements made on a separate raw sample.  相似文献   

13.
Experiments were conducted at 3 US locations (California, Idaho, and Texas) to determine the effects of dietary zilpaterol hydrochloride and duration of zilpaterol feeding on carcass composition and beef palatability. At each site, 160 steers and 160 heifers were stratified within sex by initial BW (study d -1) and assigned randomly within BW strata to 1 of 4 treatments in a randomized complete block design (4 blocks/treatment for each sex). The 4 treatments were arranged in a 2 (no zilpaterol vs. zilpaterol) x 2 (20- or 40-d duration of zilpaterol feeding) factorial. When included in the diet, zilpaterol was supplemented at 8.3 mg/kg (DM basis). Each pen consisted of 10 animals. After slaughter 2 carcasses per pen (n=64 per trial site) were selected. The entire right side of the selected carcasses was collected for dissection and chemical analysis of the soft tissue. Additionally, the left strip loin was collected for Warner-Bratzler shear force determinations and aged to 28 d postmortem. Sensory analysis was conducted on the Idaho trial site samples only. All data were pooled for analyses. Feeding zilpaterol hydrochloride increased carcass muscle deposition (P<0.01) of both steer and heifer carcasses. However, carcass percentage fat of steers and heifers was not affected (P>0.11) by the zilpaterol treatment. In heifer carcasses, carcass moisture percentage was increased (P=0.04) and bone percentage was decreased (P=0.02), whereas in steer carcasses, carcass moisture and bone percentage were not affected (P>0.10). In heifer carcasses, carcass ash percentage was not affected (P=0.61) by zilpaterol, whereas in steer carcasses, carcass ash percentage tended (P=0.07) to be increased. The protein-to-bone ratio was increased (P<0.001) by zilpaterol hydrochloride treatment in both steers and heifers, whereas the protein-to-fat ratio was not affected (P=0.10). Cooking loss of the LM was not affected (P=0.41) by zilpaterol treatment of steers or heifers. However, LM Warner-Bratzler shear force was increased (P=0.003) on average (3.3 vs. 4.0 kg) due to zilpaterol hydrochloride treatment of both steers and heifers. In both steers and heifers, LM sensory panel scores of overall juiciness (6.2 vs. 6.0), tenderness (6.2 vs. 6.0), and flavor intensity (6.2 vs. 6.0) tended (P=0.06) to be decreased in cattle supplemented with zilpaterol. Zilpaterol hydrochloride is a repartitioning agent that seems to affect carcass composition primarily through protein deposition. However, zilpaterol treatment can adversely affect tenderness and other palatability traits.  相似文献   

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15.
Steers were generated from Angus (A), Beefmaster (BM), Brangus (BA), Gelbray (GB), and Simbrah (SB) sires mated to cows of their breed and to Brahman x Hereford F1 cows (except A) to characterize their carcass traits, composition, and palatability. The 290 steers (48 A, 48 BM, 36 BA, 31 GB, and 46 SB) were slaughtered at an equal fatness end point as determined by real-time ultrasound and visual evaluation. Angus steers had lighter (P < 0.01), more youthful (P < 0.01) carcasses with a higher (P < 0.05) quality grade, more (P < 0.01) fat thickness, and a larger (P < 0.01) longissimus area/100 kg than BM-, BA-, GB-, and SB-sired steers. Angus steers also had a lower (P < 0.01) specific gravity, a higher (P < 0.01) percentage fat and less (P < 0.05) lean in the 9th to 11th rib, and steaks aged for 10 d were more tender (P < 0.01) than steaks from Brahman-derivative sired steers. The BM- and BA-sired steers had lighter (P < 0.01), more youthful (P < 0.05) carcasses, and smaller (P < 0.01) longissimus area than GB- and SB-sired steers. The 9th to 11th rib section from the BM- and BA-sired steers had less lean and more bone (P < 0.01) than GB- and SB-sired steers. The BA-sired steers had more (P < 0.01) marbling and a higher (P < 0.05) quality grade than BM-sired steers. The SB-sired steers had heavier (P < 0.01) carcasses than the GB-sired steers. There were no differences in shear force for steaks aged for 3 d for any of the breed types, but with 10 d of aging, steaks from Angus steers were more tender, possibly indicating that steaks of Brahman-derivative breeds aged at a slower rate than those from Angus.  相似文献   

16.
Research was conducted to determine the effects of supplemental dietary vitamin D3 on DMI, carcass traits, Warner Bratzler shear (WBS) force, calpastatin activity, plasma minerals, pH (0, 3, 12, and 24 h after slaughter), water-holding capacity (WHC), and sensory characteristics of three muscles. Pre-slaughter vitamin D3 treatments included no supplemental vitamin D3, 6 x 106 IU (MIU) of vitamin D3 for 4 d, or 6 MIU of vitamin D3 for 6 d. Cattle were slaughtered and carcasses were chilled for 48 h before removal of steaks from the longissimus, gluteus medius, and biceps femoris muscles. Steaks were aged at 2 degrees C for 7, 14, or 21 d before cooking to a final internal temperature of 70 degrees C for WBS and sensory panel analysis. Dry matter intake was lower for steers supplemented with vitamin D3 for 4 or 6 d. Live and carcass weights were lower (P < 0.05) in steers supplemented with vitamin D3. Supplementing 6 MIU/6 d of vitamin D3 decreased (P < 0.05) WBS values of gluteus steaks (pooled over aging times). Longissimus steaks from steers supplemented with vitamin D3 for 6 d had lower (P < 0.05) WBS force values than these steaks from control steers or steers fed vitamin D3 for 4 d at 7 d postmortem. Biceps femoris steaks from steers receiving vitamin D3 for 4 d had higher WBS values than steaks from control steers at 14 and 21 d postmortem. Feeding vitamin D3 at 6 MIU for 6 d decreased (P < 0.05) the percentage of steaks that had WBS values > or = 3.86 kg for all steaks. Feeding vitamin D3 had no effect on palatability traits evaluated by trained panelists. Blood Ca concentrations were greater (P < 0.05) when vitamin D3 was fed and with increased vitamin D3 feeding time. Feeding vitamin D3 for 6 d (vs 4 d) delayed pH decline for all muscle types after 0, 3, and 12 h postmortem. Water-holding capacity was increased (P > 0.02) after 0 h, 24 h, and 21 d postmortem when vitamin D3 was fed and was greater at 0 and 24 h if vitamin D3 was fed for 6 d rather than 4 d. These data suggest that supplementing 6 MIU of vitamin D3 will decrease DMI and improve beef tenderness through increased blood plasma Ca concentrations and WHC.  相似文献   

17.
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.  相似文献   

18.
A 2-yr experiment was conducted to compare carcass characteristics and meat palatability attributes of steers ((3/4) British, (1/4) Continental) finished postweaning as calves or yearlings. Calves and yearlings of the same contemporary group were designated to a finishing system at weaning. Calves (n = 73) were finished in the feedlot (191 d) on a high-concentrate diet. Yearlings (n = 84) grazed crop residues after weaning, followed by spring and summer pasture grazing, and concluded with a short finishing period (91 d) in the feedlot. All steers were fed to a constant, fat thickness endpoint of 1 cm. The M. longissimus lumborum steaks from each production system were aged for 7, 14, or 21 d for Warner-Bratzler shear force determination and for 7 or 14 d for in-house sensory panel evaluation. Insoluble, percent soluble, and total collagen were determined. Yearlings produced heavier (P < 0.001) carcasses with larger (P < 0.001) LM areas and lower (P < 0.001) marbling scores and quality grades. Calves possessed greater amounts of total collagen (P < 0.001), with a significantly greater percentage of soluble collagen compared with yearlings (39.72 vs. 24.38%). Calves produced steaks with lower (P < 0.001) shear force values and greater (P < 0.001) sensory ratings for flavor. The USDA Choice steaks from the calves were more (P < 0.001) tender and more (P < 0.050) palatable than Choice steaks from yearlings, and USDA Select steaks from calves were rated more tender (P < 0.001), juicy (P = 0.012), and desirable (P < 0.001) than Select steaks from yearlings. As expected, increasing aging time from 7- to 14- to 21-d produced steaks with lower (P < 0.001) shear force values, regardless of the production system. Risk probabilities showed 1.24% of the steaks from calf-finished steers and 21.22% of steaks from yearling-finished steers to be tough. Sensory rating probabilities showed the steaks from the calves were most likely to be desirable for tenderness, whereas steaks from the yearlings were most likely to be undesirable for tenderness, juiciness, flavor, and overall acceptability. Thus, calf-finished steers produce carcasses superior in quality and palatability compared with those from yearling-finished steers. However, yearling-finished steers can produce tender beef with extended aging.  相似文献   

19.
An experiment was conducted to determine the effects of zilpaterol hydrochloride mM supplementation (ZH; 8.3 mg/kg on a DM basis for 20 d) and calcium chloride injection [CaCl(2), 200 at 5% (wt/wt) at 72 h postmortem] on palatability traits of beef (Bos taurus) strip loin steaks. Select (USDA) strip loins were obtained from control (no ZH = 19) and ZH-supplemented carcasses (n = 20). Right and left sides were selected alternatively to serve as a control (no INJ) or CaCl(2)-injected (INJ) and stored at 4°C. Before injecting the subprimals (72 h postmortem), 2 steaks were cut for proximate, sarcomere length, and myofibrillar fragmentation index (MFI) analyses. At 7 d postmortem each strip loin was portioned into steaks, vacuum packaged, and aged for the appropriate period for Warner-Bratzler shear force (WBSF; 7, 14, 21, and 28 d postmortem), trained sensory analysis (14 and 21 d postmortem), purge loss (7 d), and MFI (3, 7, 14, 21, and 28 d postmortem). Results indicated steaks from both ZH supplementation and INJ had reduced WBSF values as days of postmortem aging increased. The WBSF values of ZH steaks were greater (P < 0.05) than no ZH steaks at each postmortem aging period. The INJ steaks had lower WBSF values (P < 0.05) than non-injected steaks. A greater percentage (91 vs. 71%) of steaks had WBSF values < 4.6 kg from steers with no ZH supplementation at 7 d postmortem, but the percentage did not differ (P > 0.05) due to ZH at 14, 21, or 28 d or due to INJ at any aging period. Trained panelists rated tenderness less in ZH steaks than steaks with no ZH at 14 d and 21 d. However, INJ improved (P < 0.05) the tenderness ratings and flavor intensity of the trained panelists, compared with their non-injected cohorts at 21 d. Zilpaterol hydrochloride supplementation reduced (P < 0.05) MFI values, but INJ resulted in greater (P < 0.05) MFI values compared with no INJ. Subprimals from ZH and INJ showed greater purge loss (P < 0.05). Although no interactions were found with ZH and CaCl(2), injecting USDA Select strip loins from ZH-fed cattle can help reduce the normal WBSF variation as it does in steaks from non-ZH-fed cattle.  相似文献   

20.
A split-plot design was used to study effects of male status (bull vs steer), zeranol implants, breed types (Angus vs Limousin) and electrical stimulation on palatability traits of five major muscles when all animals were fed to a similar fat-thickness endpoint. Warner-Bratzler shear (WBS) determinations and taste-panel evaluations were performed on the longissimus, adductor, semimembranosus, semitendinosus and biceps femoris muscles removed 24 h postmortem. Breed was the most consistent main effect difference, with Angus cattle having lower WBS values than Limousin for the longissimus and semitendinosus muscles. Angus cattle also were favored in many sensory traits. Few significant differences were noted between bulls and steers in taste-panel traits. Differences due to electrical stimulation were most evident in the longissimus muscle, with higher panel-evaluation scores, an enhancement of marbling and lean color and a lower incidence of heat ring. The implant tended to have negative effects on palatability in this trial. An overall ranking of the five muscles based on WBS from most tender to least tender was: adductor, semimembranosus, longissimus, semitendinosus and biceps femoris. Correlations of palatability traits of one muscle to other muscles within an experimental unit were found to be low.  相似文献   

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