Meat yield and subjective muscle scores in medium weight steers

1993 ◽  
Vol 33 (7) ◽  
pp. 825 ◽  
Author(s):  
D Perry ◽  
AP Yeates ◽  
WA McKiernan
Keyword(s):  
Negative Correlation ◽  
Regression Models ◽  
Subcutaneous Fat ◽  
Carcass Weight ◽  
Muscle Area ◽  
Eye Muscle ◽  
Meat Yield ◽  
Lean Meat ◽  
Intermuscular Fat ◽  
Medium Weight

The association between visually assessed muscle scores on live steers and their carcasses, eye muscle area, and the yield of saleable and lean meat was determined on 156 steers of mixed breeds (mean carcass weight 282 kg, mean P8 fat depth 13 mm). The contribution of subcutaneous and intermuscular fat to differences in saleable meat yield was also investigated. There was a negative correlation between P8 fat depth and both live ( r = -0.21) and carcass muscle score (r. = -0.31); therefore, the assessors were not scoring fatter steers as having better shape. The correlation between live and carcass muscle scores was 0.79. The correlation between carcass muscle score and eye muscle area was 0.58. When live muscle score, carcass muscle score, or eye muscle area was included in regression models already containing weight and fat depth, there was a significant (P<0.001) increase in the amount of variation in saleable and lean meat yield explained by the models. At the same liveweight and fat depth, a change in live muscle score from C (moderately muscled) to B (well muscled) was accompanied by an increase of 1.7% in saleable meat and 2.2% in lean meat, when these were expressed as a percentage of carcass weight. The equivalent change in carcass muscle score in carcasses of the same weight and f a t depth was accompanied by an increase of 1.9% in saleable meat and 2.4% in lean meat. The increased weight of saleable meat was not due to an increase in the dissected fat content of the meat. Weight of subcutaneous fat decreased as muscle score increased (P<0.01). There was no significant association between the amount of intermuscular fat and either live or carcass muscle score (r. = -0.075 and -0.18, respectively).

Muscle score: its usefulness in describing the potential yield of saleable meat from live steers and their carcasses

1993 ◽  
Vol 33 (3) ◽  
pp. 275 ◽  
Author(s):  
D Perry ◽  
WA McKiernan ◽  
AP Yeates
Keyword(s):  
Standard Deviation ◽  
Subcutaneous Fat ◽  
Carcass Weight ◽  
Coefficient Of Determination ◽  
Muscle Area ◽  
Potential Yield ◽  
Frame Size ◽  
Eye Muscle ◽  
Meat Yield ◽  
Residual Standard Deviation

Domestic trade weight steers (149) were assessed visually for subcutaneous fat and then given a live muscle score based on the thickness and convexity of their shape relative to frame size, having adjusted for subcutaneous fat. After slaughter, carcasses were given visually assessed carcass muscle scores based on the same critera. Fat depths at the P8 site and 12-13th eye muscle area were measured. Half of each carcass was boned-out into primal joints with subcutaneous fat trimmed to 6 mm. The weights of these joints plus meat trim (85% visual lean) were added to obtain the weight of saleable meat. The weight of fat trimmed from the carcass, primal joints, and meat trimmings during the bone-out process was added to obtain weight of fat trim. The assessors did not give steers with a greater subcutaneous fat depth better muscle scores when scoring for muscle and intermuscular fat. There was a negative correlation between live muscle score and P8 fat depth (-0.37), and no significant correlation between carcass muscle score and P8 fat depth. The associations between muscle score and yield of saleable meat were investigated using multiple regression techniques, with fat depth and muscle score sequentially added after weight in the model. The coefficient of determination and the residual standard deviation were compared at each stage. For saleable meat yield (kg), liveweight and carcass weight were the main contributors to the variation explained by the models fitted. For saleable meat yield as a percentage of carcass weight, most of the variation accounted for by the models fitted was explained by fat depth, muscle score, and eye muscle area. When added after weight and fat depth in regression models, muscle score significantly increased the coefficient of determination in all cases, with an associated decrease in the residual standard deviation. The effect was strongest for percentage of saleable meat. At the same weight and fat depth, animals or carcasses with better muscle scores produced more saleable meat.

Elliotdale and crossbred lambs: growth rate, wool production, fat depth, saleable meat yield, carcass composition and muscle content of selected cuts

1992 ◽  
Vol 32 (4) ◽  
pp. 429 ◽  
Author(s):  
DL Hopkins ◽  
KD Gilbert ◽  
KL Pirlot ◽  
AHK Roberts
Keyword(s):  
Subcutaneous Fat ◽  
Subjective Assessment ◽  
Carcass Composition ◽  
Carcass Weight ◽  
Width Ratio ◽  
Muscle Area ◽  
Eye Muscle ◽  
Meat Yield ◽  
Significant Difference ◽  
Carcass Parameters

Growth and carcass parameters were studied for 62 second-cross lambs (Poll Dorset rams over Border Leicester x Merino ewes) and 55 purebred Elliottdale lambs. Second cross lambs grew faster (P<0.001) from weaning to the first slaughter time than Elliottdale lambs and consequently weighed more and had heavier carcasses. Elliottdale lambs produced significantly (P<0.001) more wool between birth and weaning. The slope of the relationship between GR (tissue depth over the 12th rib 110 mm from the midline) and carcass weight was 1.24 � 0.23 mm/kg for second cross lambs and 0.82 � 0.17 mm/kg for Elliottdale lambs, indicating the latter lambs were leaner at heavier weights. Measures of subcutaneous fat depth at the 5th/6th and 12th/13th ribs were similar when carcass weight differences were considered for a subsample of 21 second cross and 26 purebred Elliottdale lambs. Subjective assessment of fat distribution and carcass conformation by 2 assessors revealed a significant (P<0.001) difference between breeds; second cross lambs having a better conformation. Saleable meat yield, carcass composition, and muscle content of several cuts were determined for a subsample of lambs. At a common side weight of 8 kg there was no significant difference in saleable meat yield. At this weight, crossbred lambs had a significantly (P<0.05) higher muscle content (505 g/kg) than Elliottdale lambs (480 g/kg). Fat content was similar at 300 g/kg with crossbred lambs having significantly (P<0.05) less bone (190 g/kg) than Elliottdale lambs (2 10 g/kg). The legs of carcasses from crossbred lambs were shown to contain significantly more muscle than those of Elliottdales (206 v. 195 g/kg). Carcass weight explained some of the variation in weight of leg and forequarter muscle (r2 = 0.63 and 0.61). This was improved by including an assessment for conformation from 1 assessor (r2 = 0.69 and 0.64). Eye muscle area at the 12th rib did not add significantly to the prediction; it was not different between breeds, nor was its depth to width ratio different between breeds. The pH measurements of the M. longissimus thoracis et lumborum were similar between breeds.

scholarly journals Prediction of the Hind-Leg Muscles Weight of Yearling Dairy-Beef Steers Using Carcass Weight, Wither Height and Ultrasound Carcass Measurements

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 651 ◽  
Author(s):  
Addisu Hailu Addis ◽  
Hugh Thomas Blair ◽  
Stephen Todd Morris ◽  
Paul Richard Kenyon ◽  
Nicola Maria Schreurs
Keyword(s):  
Prediction Models ◽  
Age Groups ◽  
Carcass Weight ◽  
Beef Steers ◽  
Prediction Equations ◽  
Muscle Area ◽  
Prediction Ability ◽  
Eye Muscle ◽  
Meat Yield ◽  
Leg Muscles

Prediction equations have been widely utilized for carcass classification and grading systems in older beef cattle. However, the equations are mostly relevant for common beef breeds and 18 to 24 month old animals; there are no equations suitable for yearling, dairy-origin cattle. Therefore, this study developed prediction models using 60 dairy-origin, 8 to 12 month old steers to indicate saleable meat yield from hind-legs, which would assist with carcass classification and grading. Fat depth over the rump, rib fat depth, and eye muscle area between the 12th and 13th ribs were measured using ultrasound, and wither height was recorded one week prior to slaughter. The muscles from the hind-leg were retrieved 24 h after slaughter. Prediction equations were modeled for the hind-leg muscles weight using carcass weight, wither height, eye muscle area, rump, and rib fat depths as predictors. Carcass weight explained 61.5% of the variation in hind-leg muscles weight, and eye muscle area explained 39.9% (p < 0.05). Their combination in multivariate analysis explained 63.5% of the variation in hind-leg muscles weight. The R2 of the prediction in univariate and multivariate analyses was improved when data were analyzed per age group. Additional explanatory traits for yearling steers, including body length, hearth girth, and muscle depth and dimensions measured using video image analysis scanning (VIAscan), could improve the prediction ability of saleable meat yield from yearling dairy beef steers across the slaughter age groups.

Growth and carcass characteristics of crossbred and straightbred Hereford steers. II. Carcass measurements and composition

1981 ◽  
Vol 32 (1) ◽  
pp. 171 ◽  
Author(s):  
JM Thompson ◽  
R Barlow
Keyword(s):  
Subcutaneous Fat ◽  
Carcass Characteristics ◽  
Allometric Equation ◽  
The Body ◽  
The Other ◽  
Carcass Weight ◽  
Muscle Area ◽  
Eye Muscle ◽  
Fat Thickness ◽  
Breed Crosses

The effect of sire breed on the growth and development of carcass characteristics was examined in 104 steer carcasses, over the weight range of c. 300 to 600 kg liveweight. The carcasses were obtained from 28 straightbred Hereford, 27 Brahman x Hereford, 23 Simmental x Hereford and 26 Friesian x Hereford steers, which were grown on pasture and slaughtered in four groups when the Herefords weighed c. 270, 370, 470 and 570 kg liveweight. Changes in carcass characteristics with weight were examined by using the linear form of the allometric equation (log10Y = log10A+blog10X). As liveweight increased, the proportion of carcass in the body increased (b = 1.152). At the same liveweight, Brahman cross steers had heavier carcasses than the Hereford steers, which were heavier than either the Simmental or Friesian cross steers (P < 0.05). Fat thickness at the 12th-13th rib site, and kidney and channel fat weight both increased at a proportionally faster rate than carcass weight (b = 1.511 and 1 567 respectively). At the same carcass weight, Hereford and Brahman cross carcasses had a greater fat thickness than Simmental and Friesian cross carcasses (P i 0.05). Differences between sire breeds in kidney and channel fat weight were not significant (P > 0.05). C:rcass length and eye muscle area increased at a proportionally slower rate than carcass weight (b = 0.268 and 0.466 respectively). At the same carcass weight, Friesian cross carcasses were longer, and Simmental cross carcasses had a larger eye muscle area than the other breed crosses (P < 0.05). As total side weight increased, the proportions of subcutaneous and intermuscular fatAincreased (b = 1.554 and 1.535 respectively), and the proportions of muscle and bone decreased (b = 0.938 and 0.676 respectively). At the same side weight, the Hereford and Brahman cross carcasses had more subcutaneous fat than the Simmental and Friesian cross carcasses (P < 0.05). The Hereford carcasses had more intermuscular fat than the Simmental cross carcasses, which had more muscle than the other breed crosses (P < 0.05). Friesian cross carcasses had more bone than the Simmental crosses, with Brahman cross and Hereford carcasses having the least bone (P < 0.05). Brahman cross carcasses had a higher conformation score than the Simmental cross and Hereford carcasses, the Friesian cross carcasses having the lowest (P < 0.05). Samples of the M. longissimus from Brahman cross carcasses had a higher Warner-Bratzler shear force than samples from the other breed crosses (P < 0.05).

Lamb carcass characteristics. 2. Estimation of the percentage of saleable cuts for carcasses prepared as 'trim' and traditional cuts using carcass weight, fat depth, eye muscle area, sex, and conformation score

1995 ◽  
Vol 35 (2) ◽  
pp. 161 ◽  
Author(s):  
DL Hopkins ◽  
JSA Wotton ◽  
DJ Gamble ◽  
WR Atkinson
Keyword(s):  
Full Range ◽  
Subcutaneous Fat ◽  
Carcass Weight ◽  
Significant Variable ◽  
Leg Length ◽  
Muscle Area ◽  
Eye Muscle ◽  
Percentage Yield ◽  
Ewe Lamb ◽  
Shoulder Blade

Carcass data were obtained for 172 lambs (86 ewes, 86 cryptorchids) of hot carcass weight (HCW) 16.2-28.7 kg and fat depth at the GR site (12th rib) 5-21 mm. Of these, 85 carcasses (42 ewe, 43 cryptorchid) were prepared into the full range of boneless, heavily trimmed cuts ('trim' lamb) and the remaining 87 (44 ewe, 43 cryptorchid) into traditional, trimmed bone-in cuts. Two methods of determining M. longissimus thoracis et lumborum area (EMA) produced strongly correlated results (r = 0.94; P<0.001). Conformation score using the EUROP system (1 is best, 5 is worst) was negatively correlated (r = -0.31 to -0.53; P<0.05) with measures of EMA and HCW, which were positively correlated (r = 0.64-0.71; P<0.001). Leg length was positively correlated (r = 0.36-0.76; P<0.001) with measures of EMA and HCW. Models were developed to predict the percentage yield of saleable cuts for carcasses prepared into a range of trim and traditional cuts. These identified GR as the most significant variable, so models based on GR were developed for each yield type. HCW and EMA significantly (P<0.05) improved the accuracy of estimated yield in addition to GR. By contrast, when HCW and measurements of subcutaneous fat depth over the eye muscle (FDC) were combined, EMA was not significant (P>0.05). For estimation of the percentage yield of traditional cuts, conformation score as given by an assessor significantly (P<0.05) improved the accuracy of estimation when combined with HCW and FDC. This model indicates that as conformation score increases, yield increases. Overall in terms of predicting yield, conformation score was of little value when combined with currently used carcass measures. There was a significant (P<0.05) effect of sex on the prediction of yield for 2 combinations of trim cuts that included the eye of loin. Sex also influenced (P<0.05) the prediction of yield based on traditional cuts. Where sex was significant, ewe lamb carcasses had less saleable meat by <0.5-1.0%, depending on yield type. For 4 of the trim cuts (boneless loin, eye of loin, fillet, shoulder blade), EMA added significantly (P<0.05) to the estimation of the proportions of the cuts; at constant carcass weight and fatness as indicated by GR, increases in EMA are predicted to lead to an increase in the proportion of loin cuts and a decrease in shoulder blade. For carcasses prepared into traditional cuts, EMA added significantly (P<0.05) to the estimation of leg, midloin, forequarter, and shank cuts. In all cases the coefficient was positive, indicating that increases in EMA would lead, at constant carcass weight and fatness (GR), to an increase in the proportion of these cuts in the carcass. The amount of variation (R2) explained for the individual trim cuts ranged from 0.08 to 0.72 using models that included independent variables HCW, GR, and EMA, and which accounted for the effect of sex. For traditional cuts the values ranged from 0.28 to 0.79.

Use of ultrasound in prediction of carcass characteristics in lambs

1995 ◽  
Vol 75 (2) ◽  
pp. 185-189 ◽  
Author(s):  
K. Stanford ◽  
I. Clark ◽  
S. D. M. Jones
Keyword(s):  
Stepwise Regression ◽  
Subcutaneous Fat ◽  
Lumbar Vertebra ◽  
Stepwise Discriminant Analysis ◽  
Regression Equations ◽  
Muscle Area ◽  
Maximum Width ◽  
Meat Yield ◽  
Lean Meat ◽  
Ultrasound Measurements

Longissimus muscle area, maximum depth and maximum width and subcutaneous fat thickness were measured ultrasonically at the first lumbar vertebra on 1162 lambs. Lambs were rams, ewes and wethers, ranging in age from 3 to 15 mo, with liveweights ranging from 32.5 to 70.2 kg. Subjective conformation scores of the leg, loin and shoulder and body-wall thickness at the GR site (11 cm from the carcass midline between the 12th and 13th ribs) were measured on warm carcasses and were used to determine lean-meat yield. Saleable-meat yield and percentage of saleable-meat yield in each of the primal cuts were also determined by carcass dissection of 57 of the lambs. Stepwise regression equations predicting GR and lean-meat yield from ultrasound measurements, age, (age)2, liveweight and (liveweight)2 had an R2 of 0.49 and 0.47, respectively (P < 0.15). Stepwise regression predicting saleable-meat yield by carcass dissection from ultrasound measurements, age, (age)2, liveweight and (liveweight)2 had an R2 of 0.64, with subcutaneous fat as the only significant regressor (P < 0.001). Stepwise discriminant analysis used to predict leg, loin and shoulder conformation scores from ultrasound measures, liveweight, (liveweight)2, (age)2 and age had R2 values of 0.27, 0.18 and 0.24, respectively (P < 0.15). From these data, ultrasound measurements of subcutaneous fat and longissimus depth in combination with liveweight and age appear to be valuable predictors of saleable-meat yield as determined by carcass dissection, GR and lean-meat yield but appear to be less useful in prediction of subjective muscling scores, except in the case of small-frame lambs. Key words: Ultrasound, lamb, carcass, meat yield

The significance of breed in the prediction of lamb carcass composition from fat thickness measurements

1980 ◽  
Vol 31 (3) ◽  
pp. 315-319 ◽  
Author(s):  
J. D. Wood ◽  
H. J. H. MacFie
Keyword(s):  
Subcutaneous Fat ◽  
Fat Distribution ◽  
Carcass Composition ◽  
Carcass Weight ◽  
Multiple Regression Equation ◽  
Eye Muscle ◽  
Fat Depots ◽  
Intermuscular Fat ◽  
Fat Thickness ◽  
Thickness Measurements

ABSTRACTFat thickness and measurements of the m. longissimus (‘eye’ muscle) were taken at the last rib in 350 lambs' carcasses which were fully dissected. The lambs were from two ewe breeds, Clun and Colbred, and two ram breeds, Suffolk and Hampshire, and the carcass weight range was 15 to 21kg. Castrated males and females, and singles and twins, were evenly represented.Rib fat thickness (J) was a slightly more precise predictor of the weights of lean, subcutaneous fat and subcutaneous plus intermuscular fat, when used in a multiple regression equation along with carcass weight, than fat thickness directly above the greatest depth of the ‘eye’ muscle (C). Both of these were more precise predictors than ‘eye’ muscle width and depth. Accounting for breed, either by allowing for different intercepts or completely different regression lines, did increase the proportion of variation in tissue weights explained by carcass weight and J or C, but to a small and, it was considered, commercially unimportant extent. This was despite differences in conformation between the breeds, reflected in this work by smaller ‘eye’ muscles in the ewe than the ram breeds and also in maturity, which might have been expected to influence tissue, including fat, distribution.The results indicate that breed differences in partition and distribution within and between the carcass fat depots in sheep are smaller than those between the carcass and intra-abdominal fat depots.

The area of eye muscle of beef cattle carcasses

1963 ◽  
Vol 3 (10) ◽  
pp. 249
Author(s):  
RM Seebeck
Keyword(s):  
Beef Cattle ◽  
Cross Sectional Area ◽  
Carcass Weight ◽  
Sectional Area ◽  
Muscle Area ◽  
Cross Sectional ◽  
Eye Muscle ◽  
Angus Cattle ◽  
The Cross

Variations in the cross-sectional area of eye muscle of carcasses cut between the tenth and eleventh ribs were investigated, using 105 Hereford and 51 Angus steers aged 20 months. These cattle consisted of three groups, born in successive years. At constant carcass weight, statistically significant differences in eye muscle area were found between breeds and between years. Breed and year differences were also found in eye muscle area with width and depth of eye muscle constant, so that there are limitations to the estimation of eye muscle area from width and depth measurements. A nomograph is given for estimating eye muscle area from width and depth for Hereford and Angus cattle, when all animals are reared in the same year and environment. The use of eye muscle area as an indicator of weight of carcass muscle is discussed.

Carcass characteristics of heavyweight crossbred lambs. II.* Carcass composition and partitioning of fat

1979 ◽  
Vol 30 (6) ◽  
pp. 1207 ◽  
Author(s):  
JM Thompson ◽  
KD Atkins ◽  
AR Gilmour
Keyword(s):  
Connective Tissue ◽  
Subcutaneous Fat ◽  
Carcass Characteristics ◽  
Carcass Composition ◽  
Carcass Weight ◽  
Ewe Lambs ◽  
Intermuscular Fat

Half-carcasses of 108 wether and ewe lambs from six genotypes, slaughtered at 34, 44 and 54 kg liveweight, were dissected into subcutaneous fat, intermuscular fat, muscle, bone and connective tissue. The six genotypes were the progeny of Dorset Horn and Border Leicester rams mated to Merino, Corriedale and Border Leicester x Merino first-cross ewes. As carcass weight increased, the proportion of subcutaneous and intermuscular fat increased (b > 1 ; P < 0.05) and the proportion of muscle and bone decreased (b < 1; P < 0.05). Lambs sired by Border Leicester rams had more subcutaneous fat (12.7%), more intermuscular fat (7.6%) and more bone (5.7%) than lambs sired by Dorset Horn rams at the same carcass weight (P< 0.05). Similarly, lambs sired by Dorset Horn rams had more muscle (7.2%) than lambs sired by Border Leicester rams at the same carcass weight (P < 0.05). Breed of dam had no effect on carcass composition. Wether lambs had a greater proportion of bone (5.7%) than ewe lambs at the same carcass weight (P < 0.05). The breed of sire effect and the lack of a breed of dam effect on carcass composition, in conjunction with estimated mature weights for the breeds, suggest possible differences between sire and dam breeds in the partitioning of fat between the carcass and non-carcass depots. ____________________ *Part I, Aust. J. Agric. Res., 30: 1197 (1979).

Effects of the percentage of Texel or Rouge de ľOuest genes in lambs on carcass characteristics and meat quality

1999 ◽  
Vol 69 (1) ◽  
pp. 81-92 ◽  
Author(s):  
A. F. Carson ◽  
B. W. Moss ◽  
R. W. J. Steen ◽  
D. J. Kilpatrick
Keyword(s):  
Meat Quality ◽  
Subcutaneous Fat ◽  
Carcass Characteristics ◽  
Live Weight ◽  
Fat Content ◽  
Carcass Weight ◽  
Ewe Lambs ◽  
Bone Content ◽  
Intermuscular Fat ◽  
Ram Lambs

AbstractThis study investigated the effects of the percentage of Texel or Rouge de l’Ouest (Rouge) genes in lambs (0, 50, 75 or 100%; the remainder being Greyface (Border Leicester × Scottish Blackface)) on lamb carcass characteristics and meat quality. Ewe lambs were slaughtered at 34, 40, 46 and 52 kg and ram lambs were slaughtered at 40, 46, 52 and 58 kg live weight. Dressing proportion increased (P < 0·001) by 0·53 and 0·27 g carcass weight per kg live weight for each 1% increase in Texel or Rouge genes respectively. Carcass conformation classification increased (P < 0·001) by 0·016 and 0·007 units (on a five-point scale) for each 1% increase in Texel or Rouge genes respectively. Carcass fat depth measures were reduced by Texel and Rouge genes such that at a constant fat depth end point, carcass weight could be increased by 0·029 and 0·023 kg for each 1% increase in Texel or Rouge genes. Carcass lean content increased (P < 0·001) by 0·99 and 0·27 g/kg for each 1% increase in Texel or Rouge genes. Subcutaneous fat content was reduced (P < 0·001) by 0·36 and 0·29 g/kg for each 1% increase in Texel or Rouge genes. Intermuscular fat content was reduced (P < 0·01) by 0·38 g/kg per 1% increase in Texel genes, whereas Rouge genes had no effect. Similarly, bone content was reduced (P < 0·01) by Texel genes only (0·31 g/kg per 1% increase in Texel genes). Warner-Bratzler shear force values showed a quadratic effect with increasing Texel and Rouge genes, with an initial decrease from 0 to 50% followed by an increase to 100%. Cooking loss increased (P = 0·05) as the percentage of Rouge genes in lambs increased. Increasing the percentage of Texel or Rouge genes significantly increased L* values (P < 0·01 and P < 0·05 respectively), b* values (P = 0·05 and P< 0·05 respectively) and H° values (P < 0·001).

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