The quality and yield characteristics of Canada B3 beef carcasses exhibiting medium to good muscling

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1 The quality and yield characteristics of Canada B3 beef carcasses exhibiting medium to good muscling A. Fortin 1, W. M. Robertson 1, S. J. Landry 1, and K. Erin 2 1 Agriculture and Agri-Food Canada, Lacombe Research Centre, Lacombe, Alberta, T4L 1W1. Contribution no. 961; 2 Food Processing Development Centre, Alberta Agriculture, Food and Rural Development, Leduc, Alberta T9E 7C5. Received 29 December 2000, accepted 12 October Fortin, A., Robertson, W. M., Landry, S. J. and Erin, K The quality and yield characteristics of Canada B3 beef carcasses exhibiting medium to good muscling. Can. J. Anim. Sci. 82: Forty-nine Canada B3 carcasses meeting Canada quality grade requirements, but exhibiting medium to good muscling, 12 Canada A and 13 Canada AA carcasses were selected to determine the eating attributes of LL and SM steaks and their saleable meat yield. Canada B3 LL steaks had lower (P 0.01) shear force value than Canada A and Canada AA LL steaks. For the SM steaks, there was no difference (P > 0.05). The eating attributes of Canada B3 LL steaks (softness, initial tenderness, flavour intensity, chewiness and rate of breakdown) were superior (P < 0.001) to those of Canada A or Canada AA LL steaks. Two attributes (juiciness and amount of perceptible connective tissue) were not different (P > 0.05). Differences in the eating attributes of Canada B3 SM steaks (softness, tenderness and flavour) were also observed (P < 0.05). The saleable meat yield of Canada B3 carcasses was lower (P < 0.05) than that of Canada 1 carcasses, but superior (P < 0.05) to Canada 2 or Canada 3 carcasses. Canada B3 carcasses had a higher (P < 0.05) proportion of front quarter and a lower (P < 0.05) proportion of hindquarter than Canada 1 carcasses. Canada B3 carcasses had lower yields (P < 0.05) of the more valuable cuts and higher yields (P < 0.05) of less valuable cuts, particularly, when compared to Canada 1 carcasses. Key words: Canada beef grade, quality, yield, muscling, eating attributes Fortin, A., Robertson, W. M., Landry, S. J. et Erin, K Qualité et rendement des carcasses de bovins de boucherie Canada B3 à musculature de moyenne à bonne. Can. J. Anim. Sci. 82: Les auteurs ont sélectionné 49 carcasses respectant les exigences de qualité de la classe Canada B3, mais de musculature moyenne à bonne, 12 carcasses Canada A et 13 carcasses Canada AA en vue de déterminer les propriétés organoleptiques des biftecks du longissimus lumborum (LL) et du semi-membraneux (SM), et leur rendement en viande commercialisable. Les biftecks LL des carcasses Canada B3 se caractérisent par une résistance au cisaillement plus faible (P 0,01) que ceux venant des carcasses Canada A et Canada AA. Les auteurs n ont relevé aucune variation sur ce plan pour les biftecks SM (P > 0,05). Les biftecks Canada B3 ont de meilleures ( P < 0.001) propriétés organoleptiques (tendreté, intensité de la saveur, masticabilité et rapidité de désagrégation) que les biftecks LL des carcasses Canada A ou Canada AA. Deux attributs (jutosité et proportion perceptible de tissu conjonctif) ne présentaient aucune variation (P > 0,05). Les auteurs ont aussi noté que les propriétés organoleptiques (tendreté avant et après cuisson, saveur) varient entre les biftecks SM des carcasses Canada B3. Les carcasses Canada B3 ont un rendement en viande commercialisable inférieur (P < 0,05) à celui des carcasses Canada 1, mais il est plus élevé (P < 0,05) que celui des carcasses Canada 2 ou 3. Le quartier avant des carcasses Canada B3 est proportionnellement plus gros (P < 0,05) et le quartier arrière proportionnellement plus petit (P < 0,05) que ceux des carcasses Canada 1. Les carcasses Canada B3 donnent un rendement plus faible (P < 0,05) en morceaux plus coûteux et un rendement plus élevé en morceaux de moindre valeur (P < 0,05), surtout comparativement aux carcasses Canada 1. Mots clés: Catégories de bœuf Canada, qualité, rendement, musculature, propriétés organoleptiques Maximum beef carcass value can be realized when a beef carcass achieves Canada A, Canada AA or Canada AAA quality grade [Alberta Cattle Commission (ACC) 2000]. In order to qualify for one of the Canada A grades, a carcass must be youthful and have good, with no deficiencies, to excellent muscling, bright red muscle colour, a marbling level of trace or better, fat that is firm and white or slightly tinged with a reddish or amber colour, and a minimum of 4 mm fat thickness at the grading site (Anonymous 1997a). Only carcasses qualifying for the Canada A grade series can be classified on the basis of yield into Canada 1 (59 64% lean meat), Canada 2 (54 59% lean meat) or Canada 3 (< 54% lean meat) grades. Under the current Canadian beef grading system, youthful carcasses meeting all the quality 41 grade requirements but exhibiting deficient to good muscling are assigned the Canada B3 grade. (Anonymous 1997a). Because Canada B3 carcasses return a lower yield of saleable meat (Jones et al. 1991a) they are severely discounted by the industry (ACC 2000). The validity of this severe discount is being questioned by the beef industry (Robinson 1997), at least for carcasses exhibiting medium to good muscling. It is believed that such better muscled carcasses would have sufficient marbling and adequate fat cover at the grading site to meet the requirements of the Canada A and/or Canada AA quality grades. Consequently, Abbreviations: LL, longissimus lumborum; LT, longissimus thoracis; SM, semimembranosus

2 42 CANADIAN JOURNAL OF ANIMAL SCIENCE adequately marbled Canada B3 carcasses should have eating attributes comparable to the eating attributes of Canada A and/or Canada AA carcasses. Furthermore, these carcasses, if marketed in the US, would receive a higher return, as muscling is not part of the requirements for USDA quality grades (Prime, Choice and Select) (Anonymous 1997b). Hence, these carcasses may be unfairly undervalued under the current Canadian beef grading/marketing system. If so, the current grading system should then be amended to correct this discrepancy between Canadian and American beef grading systems. However, it is recognized that the majority of the Canada B3 carcasses (deficient to good muscling) produced in Canada are carcasses from dairy breeds (Canadian Beef Grading Agency, personal communication). In 1999, fewer than 5000 carcasses or 0.2% of the graded carcasses were downgraded to the Canada B3 grade for insufficient muscling (Anonymous 2001). However, these statistics do not include the animals shipped to the US, where a better return would be expected. It is also generally acknowledged by the industry that if a Canada Yield grade were to be assigned to a Canada B3 carcass it would receive a low Canada Yield grade (Jones et al. 1993). However, no saleable meat yield data are available for carcasses having medium to good muscling and exhibiting sufficient marbling and adequate fat cover at the grading site to meet the Canada A or Canada AA quality grade requirements. Therefore, with the possibility in mind of amending the current Canadian beef grading system to correct the discrepancy described above, the two key objectives of this study were: (1) to determine whether beef carcasses showing traces, slight or small marbling and exhibiting medium to good muscling have eating attributes comparable to those of Canada A and Canada AA carcasses and (2) to characterize, in terms of saleable meat yield (closely trimmed boneless boxed beef sub-primals including the 50/75/85% visual lean trimmings), beef carcasses that have medium to good muscling and, at the same time, sufficient marbling and adequate fat cover at the grading site to meet the Canada A and Canada AA quality grade requirements. MATERIALS AND METHODS The left sides from 49 Canada B3 carcasses exhibiting medium to good muscling and the hindquarters from 12 Canada A and 13 Canada AA carcasses were selected randomly at a commercial beef packing plant in Alberta. Selection took place over five selection periods (groups). For each selection period, Canada B3, Canada A and Canada AA carcasses were represented. All animals were handled during transport and at the abattoir, and slaughtered according to standard commercial procedures used by the Canadian beef industry. All 49 Canada B3 carcasses were dairy type. The carcasses were selected at the same plant to avoid differences in palatability attributes that might have arisen from different pre-slaughter handling and postmortem chilling regimes. At the plant, the following information was collected: sex, warm carcass weight, fat thickness at the grading site, muscling score, Canada quality and yield grades, and American Meat Science Association (AMSA) marbling scores ( = traces, = slight and = small; AMSA 1990). A photographic reference scale describing the various levels of marbling was used (Official USDA Marbling Photographs, National Livestock and Meat Board, Chicago, IL). Muscling score, which is based on the rib eye length and width at the 12th rib, was determined using the Canada grade ruler. Muscle score ranges from 1 to 4 with the higher score designating a larger rib eye (Jones et al. 1991b). After selection of the carcasses at the plant, the left sides (Canada B3) and hindquarters (Canada A and Canada AA) were transported to the Lacombe Research Centre, Lacombe, AB. The loin (longissimus lumborum, LL) and inside round (semimembranosus, SM) were removed, vacuum-packed and held at 1 C to provide a total aging period of 14 d. Then, two 2.54-cm steaks were obtained from each of the LL and SM muscles. As per the American Meat Science Association recommendations (AMSA 1995), the steaks were vacuum-packed and stored at 25 C for the subsequent determination of shear force (Lacombe Research Centre, Lacombe, AB) and the assessment of eating attributes (Food Processing Development Centre, Alberta Agriculture, Food and Rural Development, Leduc, AB). Shear Force Determination The steaks were removed from the freezer, weighed and placed in a refrigerator (2 C) to thaw for 24 h. Fifteen minutes prior to grilling, the steaks were removed from the refrigerator. The steaks were grilled (Garland Grill ED30B) to an internal temperature of 40 C, turned and cooked to a final internal temperature of 72 C (Hewlett Packard HP34970A Data Logger). The internal temperature was monitored with a spear-point temperature probe (10 cm in length) inserted into the mid-point of the steaks. Upon removal from the grill, the steaks were immediately immersed in an ice/water bath to prevent further cooking. The steaks were then transferred to a cooler (2 C) for 24 h. Following cooling, six cores, 1.9 cm in diameter, were removed parallel to the fibre grain. Peak shear force was determined on each core perpendicular to the fibre grain using an Instron 4301 Material Testing System equipped with a Warner- Bratzler cell and Series 9 Software. Crosshead speed was set at 200 mm per minute. Eating Attributes Determination The steaks were removed from the freezer, held at ambient temperature (18 20 C) for 2 h and then stored in a refrigerator (4 C) overnight for thawing. On the subsequent day, the steaks were measured, weighed and then broiled on an openhearth broiler (Moffat, Model EOB24). The steaks were turned at an internal temperature of 34 C and removed from the broiler upon reaching an internal temperature of 68 C. A post-cook rise of approximately 3 C was usually observed. The internal temperatures were monitored at 5-s intervals with thermocouples attached to a data logger interfaced with recording software. Final cooked weights were recorded for the determination of cooking loss.

3 FORTIN ET AL. QUALITY AND YIELD CHARACTERISTICS OF CANADA B3 CARCASSES 43 Table 1. Definition of the eating attributes used to characterize the LL (loin) and SM (inside round) steaks from Canada B3, Canada A and Canada AA beef carcasses Attribute Softness Initial tenderness Juiciness Flavour intensity Chewiness Rate of breakdown Amount of perceptible connective tissue Definition Between the molar teeth Force required to chew three times after the initial compression Amount of moisture released after five chews Amount of full meat (beef) flavour after eight chews Energy required at the 9th chew to swallow at a constant rate Number of chews required during mastication to disintegrate the meat sample Amount of connective tissue remaining upon complete disintegration of meat sample Six to nine panellists, screened and trained according to the procedures of the American Meat Science Association (AMSA 1995) were used to evaluate the eating attributes of the LL and SM steaks (Table 1). All attributes were scored on 15-cm unstructured line scales with each end point tagged with a descriptor; softness: soft-hard, initial tenderness: tender-tough, juiciness: not juicy-extremely juicy, flavour: no beef flavour-full beef flavour, chewiness: tender-chewy, rate of breakdown: fast-slow, amount of perceptible connective tissue: none-abundant. The outer surfaces of the cooked steaks were trimmed (Siemens, Model ) and 1.25-cm cubes cut from the steaks. Each panellist received two adjacent cubes from each steak. The meat samples were placed in lidded 1-ounce glass jars labelled with three digit random codes and held in a water bath (54 C) until presented to the panellists. Water (at room temperature) and unsalted soda crackers were provided to purge the palate of residual flavours between samples (Larmond 1977). At each session, the panellists evaluated three to six randomly presented samples. Two sessions were held each day. All panel sessions were conducted in partitioned booths equipped with red fluorescent lighting in an atmospherically controlled room. Saleable Meat Yield The 49 Canada B3 left sides were cut out to obtain the saleable meat yield [closely trimmed (0.625 cm) boneless boxed beef sub-primals including the 50/75/85% visual lean trimmings] and the yield of individual sub-primal cuts (Canadian Meat Council 1993). Contemporary cutout data for Canada 1 (n = 232), Canada 2 (n = 147) and Canada 3 (n = 46) carcasses from an on-going project to develop the Lacombe Computer Vision System (CVS ) for beef carcass grading were used as control (A. K. W. Tong, Lacombe Research Centre, unpublished data). Table 2. Characteristics of Canada B3, Canada A and Canada AA beef carcasses selected in this experiment Canada B3 Canada A Canada AA Number of carcasses Hot carcass weight (kg) 331.9c (5.54) z 307.4a (0.36) 286.1b (0.68) Rib eye area (cm 2 ) 73.4c (0.48) 87.1a (1.14) 83.3b (1.04) Marbling (AMSA) 482.5c (3.09) 356.6a (7.37) 449.0b (6.58) Grade fat (mm) 4.6b (0.08) 7.0a (0.19) 6.9a (0.17) z Least-squares means (standard error). a c Means within the same row not sharing a common letter are significantly different from each other (P 0.01). Statistical Analyses All data were analyzed using the General Linear Model procedure of the SAS Institute, Inc. (1999). For the carcass and yield data, a model containing grade as a fixed effect was adopted. The shear force data were analyzed using a model that contained group (day when the carcasses were selected), grade, core as fixed effects and their interactions. The error term to test the effect of grade was the carcass within group by grade mean squares. For the eating attributes data, the following model was used: group, grade, panellist, evaluation day as fixed effects and their interactions. The error term used to test the effect of grade was the carcass within group by grade mean squares. Significant differences between least-squares means for grade were tested by Duncan s multiple range test (Steel and Torrie 1980). RESULTS AND DISCUSSION Compared to Canada A and Canada AA carcasses, Canada B3 carcasses had the heaviest (P 0.01) average hot carcass weight, the lowest (P 0.01) average grade fat, the smallest (P 0.01) average rib eye area, and the highest (P 0.01) average AMSA marbling score (Table 2). In the final report of the National Beef Carcass Cut Out Study, Jones et al. (1993) reported a similar average AMSA marbling of 470 for dairy type steer carcasses. In our study, of the 49 Canada B3 carcasses, 3 had marbling characteristics similar to Canada A (traces marbling) carcasses, 30 carcasses had marbling characteristics similar to Canada AA (slight marbling) and 16 carcasses had marbling characteristics similar to Canada AAA (small marbling) carcasses. Dubeski et al. (1997a, b) have also shown that dairy breeds can produce carcasses with as much intramuscular fat and similar marbling characteristics as beef breeds. It is important to appreciate that the selection criteria for the Canada B3 carcasses was the degree of muscling. Hence, based on the results of this study, it would be fair to assume that under current Canadian production conditions, carcasses with medium to good muscling generally can have marbling characteristics that would meet the requirements of the Canada quality grades. However, the smaller rib eye area for the Canada B3 carcasses, despite being heavier, illustrates clearly one of the reasons the industry has discriminated against carcasses exhibiting medium to good muscling.

4 44 CANADIAN JOURNAL OF ANIMAL SCIENCE Shear Force LL steaks from Canada B3 carcasses had a lower (P 0.01) shear value than LL steaks from Canada A and Canada AA carcasses, whereas for the SM steaks there was no difference (P > 0.05) between Canada B3 and Canada A or Canada AA grades (Table 3). Our shear force values are comparable to those reported by Aalhus et al. (2000) who used the same laboratory technique that was used for this study. The shear values for the LL steaks were lower (in the order of 1.23 to 2.21 kg; P 0.01) than the values for the SM steaks. The same phenomenon was also observed by Aalhus et al. (2000) further illustrating the muscle-to-muscle variation in eating attributes. The overall average values only give a partial indication of the effect of grades. The extent of variation (standard error) in the shear values is also critical in determining the effect of a given treatment. In our study, the standard errors of the mean for the LL and SM steaks from Canada B3 carcasses were lower (compared to Canada A and Canada AA carcasses); thereby indicating less variation in the shear values. Aalhus et al. (2000) proposed shear value thresholds to define meaningful degrees of objective measure of tenderness. For LL steaks, they proposed the following thresholds: tough > 9.60 kg, slightly to moderately tough kg, slightly to moderately tender kg and tender < 5.60 kg. For SM steaks, the proposed thresholds were: tough > 9.91 kg, slightly to moderately tough kg, slightly to moderately tender kg and tender < 5.89 kg. Using these shear value thresholds, the distributions are presented in Fig. 1a and 1b, respectively, for the LL and SM steaks. For the LL steaks (Fig. 1a), no steaks from Canada B3 carcasses were deemed to be slightly to moderately tough or tough. Furthermore, only 1 (8%) LL steak from Canada AA carcasses and none from the Canada A carcasses were deemed to be slightly to moderately tough, suggesting a lack of association of marbling with shear force. Jones et al. (1991a) and Jeremiah (1996) also reported a low relationship between shear force and marbling in longissimus thoracis (LT) steaks. For the SM steaks obtained from the Canada B3 carcasses (Fig. 1b), six steaks, or less than 13%, were in the slightly to moderately tough or tough categories. However, this incidence was lower than that of slightly to moderately tough / tough SM steaks from Canada A carcasses (33.3%), but slightly higher than for the SM steaks from Canada AA carcasses (7.6%). As for the LL steaks, shear force in the SM steaks did not appear to be associated with marbling. In their study, Aalhus et al. (2000) reported that less than 19% of LL steaks and SM roasts from Canada A, Canada AA and Canada AAA carcasses (approximately 240) fell into the tough and slightly to moderately tough categories based on shear force. Furthermore, less than 10% of the LL steaks and SM roasts fell into the tough category. Their sensory evaluation results showed similar trends. Hence, based on the results of Aalhus et al. (2000), it can be stated that, in our study, the shear force characteristics of LL and SM steaks from Canada B3 carcasses that exhibit medium to good muscling and have sufficient marbling to meet the requirements of the Canada A and/or Canada AA Table 3. Shear force and eating attributes of the LL (loin) and SM (inside round) steaks from Canada B3, Canada A and Canada AA beef carcasses Grade Canada B3 Canada A Canada AA LL steaks Shear force (kg) 4.69b (0.108) z 5.65a (0.252) 5.32a (0.224) Softness 6.4b (0.15) 7.5a (0.32) 7.8a (0.32) Initial tenderness 5.9b (0.17) 7.2a (0.35) 7.7a (0.35) Juiciness 7.6 (0.16) 7.1 (0.35) 6.9 (0.34) Flavour 11.4b (0.07) 10.8a (0.17) 10.4a (0.16) Chewiness 5.6b (0.18) 6.8a (0.37) 7.8a (0.37) Rate of breakdown 6.8b (0.13) 7.8a (0.28) 8.2a (0.27) Connective tissue 3.3 (0.19) 3.1 (0.39) 3.6 (0.39) % cooking loss y 22.6 (0.52) 22.4 (0.94) 24.4 (1.01) SM steaks Shear force (kg) 6.86 (0.165) 7.19 (0.394) 6.43 (0.351) Softness 7.0b (0.128) 7.7a (0.23) 7.8a (0.28) Initial tenderness 6.5e (0.15) 7.3d (0.28) 7.4d (0.34) Juiciness 7.8e (0.13) 7.3d (0.25) 7.2d (0.30) Flavour 11.4b (0.08) 11.2ab (0.16) 10.7ac (0.19) Chewiness 6.5 (0.18) 7.3 (0.33) 7.3 (0.39) Rate of breakdown 7.5 (0.14) 7.9 (0.26) 7.9 (0.31) Connective tissue 6.4 (0.22) 6.8 (0.42) 6.6 (0.50) % cooking losses 26.6 (0.55) 27.6 (1.03) 28.4 (1.23) z Least-squares means (standard error). y Adjusted for pre-cooked weight. a c Means within the same row not sharing a common letter are significantly different from each other (P 0.01). d, e Means within the same row not sharing a common letter are significantly different from each other (P 0.05). quality grades fell well within the norm of the Canadian beef population. Eating Attributes The eating attributes of the LL steaks from Canada B3 carcasses (softness, initial tenderness, juiciness, flavour intensity, chewiness, rate of breakdown and amount of perceptible connective tissue), as determined by a trained panel, were generally superior to the eating attributes of LL steaks from Canada A or Canada AA carcasses (Table 3). Steaks from Canada B3 carcasses were softer (P 0.001), had greater initial tenderness (P 0.001), had a lower degree of chewiness (P 0.001) and broke down faster (P 0.001) compared to steaks from Canada A or Canada AA carcasses. Additionally, the LL steaks from Canada B3 carcasses were perceived to have fuller (P 0.001) beef flavour. The two attributes that did not differ (P > 0.05) were juiciness and the amount of perceptible connective tissue. No differences (P > 0.05) in any eating attributes were found in the LL steaks from Canada A and Canada AA carcasses. Differences in the eating attributes of SM steaks from Canada B3 carcasses compared to SM steaks from Canada A or Canada AA carcasses were not of the same magnitude as those of LL steaks. However, trained panellists did find the SM steaks from Canada B3 carcasses softer (P 0.01), more tender (P 0.05) and more flavourful (P 0.05). The level of chewiness, the rate of breakdown and amount of perceptible connective tissue were similar (P > 0.05) for steaks across all three grades. SM steaks from Canada B3

5 FORTIN ET AL. QUALITY AND YIELD CHARACTERISTICS OF CANADA B3 CARCASSES 45 Fig 1. (a) Distribution of LL (loin eye) steaks among the four categories of tenderness as defined by the shear force value. (b) Distribution of SM (inside round) steaks among the four categories of tenderness as defined by the shear force value. carcasses were juicier (P 0.05) than the SM steaks from Canada A and Canada AA carcasses. Like the LL steaks, the SM steaks from Canada A and Canada AA carcasses were similar in all eating attributes (P > 0.05). The conclusions pertaining to the eating attributes associated with tenderness corroborate the findings observed with shear force, also an indicator of tenderness. In our study, the selected Canada B3 carcasses had more marbling (P 0.001) and produced LL and SM steaks that were as tender or more tender than the LL and SM steaks from Canada A and/or Canada AA carcasses. This is consistent with the small but positive relationship between marbling and tenderness that has been reported numerous times in the scientific literature a b (Carpenter 1984; Jones et al. 1991a; Wheeler et al. 1994; Jeremiah 1996). The lack of association between juiciness and marbling (LL steaks) was also reported by Jeremiah (1996). In studies (Carpenter 1984; Jones et al. 1991a; Wheeler et al. 1994) in which an association between juiciness and marbling was described, the range of marbling far exceeded the range found in our study. Our results are further evidence that the relationships between marbling and eating attributes are, if they exist at all, relatively small. Finally, the lack of consistency between the LL and SM steaks in the impact of marbling on eating attributes illustrates the between-muscle variation observed by others (Aalhus et al. 2000).

6 46 CANADIAN JOURNAL OF ANIMAL SCIENCE Table 4. Characteristics of Canada B3, Canada 1, Canada 2 and Canada 3 carcasses Grade Canada B3 Canada 1 Canada 2 Canada 3 Number of carcasses Hot carcass weight (kg) (5.54) z (2.43) (3.35) (5.73) Rib eye area (cm 2 ) 73.4d 90.5a 81.9b 77.0c (0.48) (0.76) (0.89) (1.34) Grade fat (mm) 4.6d 6.4c 11.9b 17.8a (0.08) (0.13) (0.17) (0.44) Front quarter (% of side) 55.4a 54.5b 55.1a 55.3a (0.18) (0.08) (0.09) (0.15) Hind quarter (% of side) 44.6b 45.5a 44.9b 44.7b (0.18) (0.08) (0.09) (0.15) Salable meat yield (%) 72.6b 74.2a 72.0c 70.4d (0.24) (0.15) (0.20) (0.39) z Least-squares means (standard error). a d Means within the same row not sharing a common letter are significantly different from each other (P 0.05). Cooking Loss No differences in cooking loss were observed (P > 0.05) between the three grades, for either LL or SM steaks (Table 3). Jeremiah, in several studies (Jeremiah 1996; Jeremiah et al. 1997) also showed that marbling was barely associated with cooking loss. In his 1996 study, he reported a correlation of less than Saleable Meat Yield In the present study, Canada B3 carcasses were from dairy type cattle with medium to good muscling. They were compared to contemporary Canada 1, Canada 2 and Canada 3 beef carcasses (A. K. W. Tong, Lacombe Research Centre, unpublished data) (Table 4). By industry standards, Canada 1 carcasses have the highest monetary value followed by Canada 2 and Canada 3 carcasses (ACC 2000). Hence, it is appropriate to emphasize a Canada B3 - Canada 1 comparison. In our study, Canada B3 carcasses with medium to good muscling had smaller rib eye area (P 0.01) when compared to Canada 1 carcasses (73.4 vs.90.5 cm 2 ). Similarly, fat thickness at the grading site was also lower (P 0.05), still meeting, however, the minimum grade fat requirements of 4 mm for Canada quality grades (Anonymous 1997a). For Canada B3 carcasses, the saleable meat yield was lower (P 0.01) than that of Canada 1 (72.6 vs. 74.2%). Canada B3 carcasses had a higher (P 0.01) proportion of front quarter and lower (P 0.01) proportion of hindquarter than Canada 1 carcasses. However, when compared to Canada 2 or Canada 3 carcasses there was no difference (P > 0.05). Jones et al. (1993) reported that, at equal carcass weight and equal fatness, dairy carcasses had lower saleable meat yield (74.1 vs. 76.6%) than beef carcasses. They ascribed the lower yield to higher bone content, greater amounts of inter-muscular fat and lower rib eye area. Under the current Canadian grading regulations, rib eye area and grade fat are used to derive a yield grade, rib eye area being positively related to yield and grade fat negatively related to yield (Anonymous 1997a). In our study, rib eye area had a more pronounced influence than grade fat in determining the yield grade. Consequently, had these Canada B3 carcasses been graded, the majority of them would have received a Canada 2 or Canada 3 grade. Among the high valued cuts, the steak style rib (P 0.01) and the strip loin (P 0.01) from Canada B3 carcasses had lower yield and the sirloin tip (P 0.01) a higher yield when compared to Canada 1 carcasses (Table 5). No difference in the yield of the top butt and tenderloin was observed (P > 0.05) between Canada B3 and Canada 1 carcasses. Finally, among the moderately valued and the low-valued cuts, yields from Canada B3 carcasses were either similar to or higher than those from Canada 1 carcasses. Table 5. Yield (% of side) of selected cuts of Canada B3, Canada 1, Canada 2 and Canada 3 beef carcasses Grade Canada B3 Canada 1 Canada 2 Canada 3 Front quarter Blade eye (M) y 4.8ab (0.12) z 4.9a (0.05) 4.7bc (0.07) 4.4c (0.13) Short cut clod (M) 3.9b (0.05) 4.1a (0.02) 3.9b (0.03) 3.7c (0.05) Chuck tender (L) 1.0a (0.01) 0.9b (0.01) 0.8c (0.01) 0.7d (0.01) Flat iron (L) 1.6a (0.02) 1.1b (0.01) 1.0c (0.01) 1.0c (0.02) Brisket point (L) 2.8a (0.05) 2.7b (0.02) 2.6bc (0.03) 2.6c (0.5) Navel (L) 3.1ab (0.09) 3.0b (0.04) 3.1b (0.05) 3.3a (0.09) 2 3 steak style rib (H) 4.1bc (0.05) 4.3a (0.02) 4.1b (0.03) 4.0c (0.05) Neck (L) 2.2a (0.12) 2.0b (0.06) 2.0ab (0.07) 2.0ab (0.12) Shoulder (L) 2.7a (0.07) 1.5b (0.03) 1.5b (0.04) 1.4b (0.07) Hind quarter Inside round (M) 5.7b (0.06) 6.2a (0.03) 5.7b (0.04) 5.4c (0.07) Gooseneck (M) 6.6c (0.08) 7.6a (0.04) 7.2b (0.05) 7.0b (0.08) Sirloin tip (H) 3.4a (0.04) 3.1b (0.02) 2.8c (0.02) 2.7d (0.04) Top butt (H) 3.3a (0.04) 3.4a (0.02) 3.2b (0.02) 3.1b (0.04) 1 0 strip loin (H) 2.8d (0.03) 3.2a (0.02) 3.1b (0.02) 2.9c (0.03) Tenderloin (H) 1.6a (0.02) 1.6a (0.01) 1.5b (0.01) 1.4c (0.02) z Least-squares means (standard error). y L = low valued cut; M = moderately valued cut; H = high valued cut. a d Means within the same row not sharing a common letter are significantly different from each other (at least P 0.05).

7 FORTIN ET AL. QUALITY AND YIELD CHARACTERISTICS OF CANADA B3 CARCASSES 47 CONCLUSIONS Canada B3 carcasses, which were youthful, had bright red muscle colour, a marbling level of trace or better, fat that was firm and white or slightly tinged with a reddish or amber colour, a minimum of 4 mm fat thickness at the grading site, and exhibited medium to good muscling, generally had eating quality characteristics equal to or better than those observed in carcasses with Canada quality grades A and/or AA. In addition, the yield characteristics of these carcasses put them intermediate between Canada 1 and Canada 2 beef carcasses. Under the current Canadian Beef Grading System, these carcasses are assigned the Canada B3 grade with a resulting severe financial penalty. Hence, it would appear that the concerns expressed by the industry about the unfair grade assignment of the better-muscled carcasses, i.e., carcasses exhibiting medium to good muscling, were justified. Therefore, corrective actions such as changes in the Canadian Beef Grading System and/or changes in the settlement structure between the producers and beef packing plants should be undertaken by the industry to address this issue. The former has been addressed in a proposal to change the muscling requirements for Canada quality grades from good, with no deficiencies, to excellent to good, with some deficiencies, to excellent (Anonymous 2001). Reducing the minimum muscling requirements should allow some of the current Canada B3 carcasses to move up to higher grades and hence, be of higher value for producers, packers, retailers and consumers. ACKNOWLEDGEMENTS This project was funded by the Canadian Beef Grading Agency and the Matching Investment Initiative of Agriculture and Agri-food Canada. The contribution of Don Brereton and his staff in preparing the carcasses is also greatly appreciated. Aalhus, J. L., Jeremiah, L. E., Dugan, M. E. R., Larsen, I. L. Best, D. R., Thacker, R., Costello, F. and Gibson, L Beef Tenderness strategy: A final report to the Canadian Cattlemen s Association. Calgary, AB. 65 pp. Alberta Cattle Commission Daily cattle report. [Online] Available: [October 2000]. American Meat Science Association Recommended procedures for beef carcass evaluation and carcass contests. AMSA in cooperation with the Beef Industry Council. 3rd ed. 16 pp. American Meat Science Association Research guide for cookery sensory evaluation and instrumental tenderness measurements of fresh meat. AMSA in cooperation with the National Live Stock and Meat Board, Chicago, IL. Anonymous 1997a. Canada Agricultural Products Act. Regulations amending the Livestock and Poultry Carcass Grading Regulations (SOR/97-368). Canada Gazette Part II, Vol. 131, No. 17. pp Anonymous. 1997b. United States Department of Agriculture. United States standards for grades of beef carcass. [Online] Available: [October 2000]. Anonymous Regulations amending the Livestock and Poultry Carcass Grading regulations. Canada Gazette Part I. 2 June pp Canadian Meat Council Standard Canadian boxed beef specifications. Canadian Meat Council Sub-committee on Boxed Beef Specifications, Ottawa, ON. Carpenter, Z. L Beef quality grade standards. Need for modification. Proc. 27th Ann. Rec. Meat Conf. 27: Dubeski, P. L., Jones, S. D. M., Aalhus, J. L. and Robertson, W. M. 1997a. Canadian, American, and Japanese carcass grades of heifers fed to heavy weights to enhance marbling. Can. J. Anim. Sci. 77: Dubeski, P. L., Aalhus, J. L. Jones, S. D. M., Robertson, W. M. and Dyck, R. S. 1997b. Meat quality of heifers fattened to heavy weights to enhance marbling. Can. J. Anim. Sci. 77: Jeremiah, L. E The influence of subcutaneous fat thickness and marbling on beef. Palatability and consumer acceptability. Food Res. Int. 29: Jeremiah, L. E., Aalhus, J. L., Robertson, W. M. and Gibson, L. L The effects of grade, gender, and postmortem treatment on beef. I. Composition, cutability, and meat quality. Can. J. Anim. Sci. 77: Jones, S. D. M., Jeremiah, L. E., Tong, A. K. W., Lutz, S. and Robertson, W. M. 1991a. The effects of marbling level, electrical stimulation and post-mortem aging on the cooking and palatability properties of beef rib-eye steaks. Can. J. Anim. Sci. 71: Jones, S. D. M., Tong, A. K. W. and Talbor, S. 1991b. Evaluation of the grade ruler approach for the yield grading of beef carcasses. Industry/Government Consultation Committee. Minutes of 8 November Jones, S. D. M., Richmond, R. J., Robertson, W. M. and Talbot, S Final report: The National Beef Carcass Cut Out Study. AAFC Lacombe Research Station, Lacombe, AB. Larmond, E Laboratory methods for sensory evaluation of foods. Agriculture Canada, Ottawa, ON. Publ Robinson, R Minutes of the industry/government Beef Grading Committee meeting. Montréal, QC. 4 Feb SAS Institute, Inc SAS users guide: Statistics. SAS for Windows, Version 8. SAS Institute, Inc., Cary, NC. Steel, R. G. D. and Torrie, J. H Principles and procedures of statistics. 2nd ed. McGraw-Hill Book Company, Toronto, ON. Wheeler, T. L., Cundiff, L. V. and Koch, R. M Effect of marbling degree on beef palatability in Bos taurus and Bos indicus cattle. J. Anim. Sci. 72:

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