Estimation of the carcass composition of different cattle breeds and crosses from fatness measurements and visual assessments

SUMMARYCarcass data for 1053 steers from the Meat and Livestock Commission's beef breed evaluation programme were used to examine the relative precision of alternative fatness assessments for predicting carcass lean percentage. The data were from four trials and comprised both dairy-bred and suckler-bred cattle by a wide range of sire breeds.A visual assessment of carcass subcutaneous fat content to the nearest percentage unit (SFe) was the single most precise predictor both overall (residual S.d. = 2·28) and within breed (residual S.d. = 2·05). Precision was improved by the addition in multiple regression of the percentage perinephric and retroperitoneal fat (KKCF) in carcass, a visual score of the degree of marbling in the m. longissimus and selected fat thickness measurements taken by calipers on cut surfaces (residual S.d. = 2·11 (overall) and 1·90 (within breed)).When the best overall equation was applied to the breed means, there was substantial bias (predicted – actual carcass lean percentage). Biases ranged from +2·5 (purebred Canadian Holstein and Luing) to – 1·3 (Limousin crosses).Breeds differed significantly in carcass lean content when compared at equal levels of fatness measurements. The differences depended both on the precision with which the measurements predicted carcass lean content and the observed differences in carcass composition that existed before adjustments to equal fatness were made.The robustness of prediction equations was examined by applying them to independent sets of data (a total of 334 carcasses) from four other trials involving steers, heifers, cows and young bulls. Equations were stable for cattle of the same breed, sex and similar levels of fatness but important bias was found between more extreme types of cattle.

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Estimation of the carcass composition of different cattle breeds and crosses from conformation assessments adjusted for fatness

The Journal of Agricultural Science ◽

10.1017/s0021859600063814 ◽

1986 ◽

Vol 106 (2) ◽

pp. 239-254 ◽

Cited By ~ 15

Author(s):

A. J. Kempster

Keyword(s):

Subcutaneous Fat ◽

Visual Assessment ◽

Carcass Composition ◽

Point Scale ◽

Fat Percentage ◽

Beef Breed ◽

Independent Variables ◽

Wide Range ◽

Precise Prediction ◽

Substantial Bias

SUMMARYCarcass data for 1053 steers from the Meat and Livestock Commission's beef breed evaluation programme were used to examine the prediction of carcass composition from conformation-related characteristics corrected to equal fatness. The data were from four trials and comprised both dairy-bred and suckler-bred cattle by a wide range of sire breeds.When used with carcass weight (W) and a visual assessment of carcass subcutaneous fat percentage (SFe) (the most precise simple assessment of carcass lean percentage, residual S.d. = 2·28), m. longissimus area (MLA) at the 10th rib was the most effective conformation-related assessment (residual S.d. = 2·10). Precision was improved by the further addition of a visual conformation assessment (C15) on a 15-point scale (residual S.d. = 2·06). The use of equations combining W, SFe, MLA, C15 and other simple assessments of fatness improved the precision further (residual S.d. = 1·94).The measurement combinations above also provided a significant prediction of the percentage of total carcass lean distributed in the higher-priced joints. Residual S.d.s were: W + SFe, (1·12); W + SFe + MLA (1·07); W + SFe + MLA + C15 (1·06).When the equations were applied to the breed means, there was substantial bias (predicted – actual carcass lean percentage). Bias ranged from approximately + 1·5 (purebred Canadian Holsteins and Luings ) to – 1·6 (Limousin crosses). The accuracy of carcass lean prediction was not improved by the addition of bone measurements to the equations but there was some improvement in the prediction of lean to bone ratio: cattle with light, thin bones tended to have higher ratios.Similar combinations of independent variables were found to provide the most precise prediction within breed.

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The estimation of beef carcass composition from subcutaneous fat measurements taken on the intact side using different probing instruments

The Journal of Agricultural Science ◽

10.1017/s0021859600036558 ◽

1983 ◽

Vol 101 (1) ◽

pp. 241-248 ◽

Cited By ~ 7

Author(s):

J. P. Chadwick ◽

A. J. Kempster

Keyword(s):

Subcutaneous Fat ◽

Thickness Measurement ◽

Carcass Composition ◽

Relative Precision ◽

Precise Prediction ◽

Fat Thickness ◽

Fat Score ◽

Thickness Measurements ◽

Single Predictor ◽

Made In

SUMMARYFat thickness measurements, taken over the M. longissimus between the 6th and 13th ribs by the automatic-recording probes, SFK Meat-Fat probe (MF), Hennessy and Chong Fat Depth Indicator (FDI) and Ulster probe (UP), and a simple ruler probe (RP), were compared with one another and a visual fat score (VSC) in terms of the precision with which carcass lean and subcutaneous fat percentages were predicted. The comparisons were made in four separate trials with RP and VSC common to all of them. A total of 182 carcasses were involved; 130 of these were probed both hot and cold. Comparisons were made among carcasses of the same weight.VSC was the best single predictor in most circumstances. Fat thickness measurements taken on the cold carcass provided a more precise prediction than those taken on the hot carcass. There was an interaction between the relative precision of the MF and RP probes and the condition of the carcass: the former generally gave the more precise prediction on cold carcasses and the latter on hot carcasses. Measurements taken by FDI tended to be better predictors than those taken by RP on both hot and cold carcasses. The use of two fat thickness measurements gave an improvement in precision over the best individual fat thickness measurements. There was also an improvement in precision in most circumstances when a fat thickness measurement was used in addition to VSC.There was little indication that specific fat measurements were particularly precise predictors when taken by specific probes, and no fat measurement was consistently the best predictor. A measurement taken 7·5 cm from the dorsal mid line at the 6th rib occurred most commonly in pairs of measurements giving the most precise prediction.

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

Animal Science ◽

10.1017/s000335610002465x ◽

1980 ◽

Vol 31 (3) ◽

pp. 315-319 ◽

Cited By ~ 25

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.

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An assessment of carcass probes for use in Great Britain for the EC pig Carcass Grading Scheme

Animal Science ◽

10.1017/s0003356100040423 ◽

1989 ◽

Vol 48 (2) ◽

pp. 427-434 ◽

Cited By ~ 14

Author(s):

G. L. Cook ◽

J. P. Chadwick ◽

A. J. Kempster

Keyword(s):

Great Britain ◽

Subcutaneous Fat ◽

Optical Probe ◽

Carcass Composition ◽

Coefficient Of Determination ◽

The Third ◽

Slaughter Pigs ◽

Fat Thickness ◽

Statistical Criteria ◽

Do So

ABSTRACTTo gain approval for use in the revised European Community (EC) Pig Grading Scheme to be introduced in 1989, methods of estimating carcass lean proportion must be shown to do so with a coefficient of determination greater than 0·64 and a residual s.d. of less than 25 g/kg. A trial was carried out to assess a number of methods for use in the EC Scheme as applied in Great Britain. Subcutaneous fat and m. longissimus depths at the head of the last rib and at the third/fourth from last rib were measured using the optical probe (OP), the Fat-O-Meater (FOM), the Hennessy Grading Probe II (HGP) and the Destron PG-100 Probe (DST) on a broad sample of 162 commercial carcasses representative of the ranges in fatness and weight found nationally. The left side of each carcass was separated into component tissues. Although the instruments all achieved similar levels of accuracy in predicting carcass lean proportion, some differences were found. The DST just failed to reach the required statistical criteria for approval in the EC Scheme. The results for the other three instruments were submitted to Brussels as evidence of suitability and they have been approved.Using the regression relationships found between carcass composition and fat thickness together with results from earlier studies, it was estimated that the carcass separable fat proportion of British slaughter pigs has fallen at the annual rate of 7 g/kg since 1975.

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THE EFFECT OF RIBBING SITE ON FAT THICKNESS MEASUREMENTS AND THE PREDICTION OF BEEF CARCASS COMPOSITION

Canadian Journal of Animal Science ◽

10.4141/cjas86-057 ◽

1986 ◽

Vol 66 (2) ◽

pp. 541-545

Author(s):

S. D. M. JONES ◽

A. K. W. TONG ◽

A. H. MARTIN ◽

W. M. ROBERTSON

Keyword(s):

Key Words ◽

Fat Content ◽

Carcass Composition ◽

Prediction Equations ◽

Beef Carcasses ◽

Fat Thickness ◽

Standard Deviations ◽

Thickness Measurements ◽

Beef Carcass

Over a 2-yr period, 409 beef carcasses were used to assess the differences of ribbing site (11/12th vs. 12/13th) on fat thickness measurements and the use of these measurements to predict carcass composition. Minimum fat thickness taken at the location specified for use under Canadian beef carcass grading procedures was 1.6 mm less, averaged over all carcasses at the 13th rib, compared with the same measurement taken at the 12th rib. Prediction equations for estimating carcass lean or fat content based on coefficients of determination and residual standard deviations had similar precision using fat thickness measurements from either ribbing site. These results are discussed in reference to National carcass grading procedures. Key words: Carcass grading, fat thickness, carcass composition

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THE ACCURACY OF TWO RECORDING INSTRUMENTS IN THE MEASUREMENT OF SUBCUTANEOUS FAT THICKNESS IN PORK CARCASSES

Canadian Journal of Animal Science ◽

10.4141/cjas82-089 ◽

1982 ◽

Vol 62 (3) ◽

pp. 731-738 ◽

Cited By ~ 11

Author(s):

S. D. M. JONES ◽

O. B. ALLEN ◽

C. R. HAWORTH

Keyword(s):

Key Words ◽

Repeated Reading ◽

Subcutaneous Fat ◽

Average Bias ◽

Average Residual ◽

Subcutaneous Fat Thickness ◽

Fat Thickness ◽

Standard Deviations ◽

The Right ◽

Thickness Measurements

The Hennessy and Chong Fat Depth Indicator (FDI) and a compact, ultrasonic instrument (Renco) were compared using 152 pork carcasses. Fat thickness measurements were taken 5 cm off the midline at five locations (shoulder, SF; mid-back, MB; last rib, LR; loin, LO; and lumbar, LU) on both sides of the carcass immediately after sticking (before scalding), after splitting the carcass and 24 h postslaughter (FDI only). Actual thicknesses were determined, using a ruler, for these locations on the left side and at the midline of the split carcass. Instrument readings made on the right or left side of the carcass were not different (P > 0.05). Precision (similarity of first and repeated reading of fat thickness) was higher for the FDI than the Renco with average residual standard deviations for both instruments being 1.2 mm and 1.4 mm, respectively. Precision was similar for all locations except the SF site which had significantly (P < 0.05) poorer values. The average bias was smaller for the FDI than for Renco, but was not large for either instrument except at the shoulder. However, regressions of instrument readings on ruler measurements for both instruments gave slopes that were considerably lower (P < 0.05) than unity with positive values for intercepts. This indicates that fat thickness would be over- and under predicted in lean and fat carcasses, respectively, using both instruments. Key words: Swine, carcass backfat, ultrasonic, fat probes

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Evaluation of electronic meat-measuring equipment in predicting carcass composition in the live pig

Animal Science ◽

10.1017/s0003356100036679 ◽

1987 ◽

Vol 45 (1) ◽

pp. 97-102 ◽

Cited By ~ 4

Author(s):

S. M. Joyal ◽

S. D. M. Jones ◽

B. W. Kennedy

Keyword(s):

Measuring Equipment ◽

Treatment Effects ◽

Carcass Traits ◽

Subcutaneous Fat ◽

Live Weight ◽

Carcass Composition ◽

Total Weight ◽

Backfat Thickness ◽

Yorkshire Pigs ◽

Fat Thickness

AbstractAn electronic meat-measuring equipment (EMME) determination (average of three consecutive readings) and backfat thickness (averaged over two sites) were taken on each of 107 live Yorkshire pigs weighing approximately 110 kg. After slaughter, 10 carcass traits: killing out, grade fat (fat thickness at maximum loin of split carcass), in. longissimus area, total and individual weights of the four untrimmed primal cuts (butt, picnic, loin and ham) and total weight of lean and subcutaneous fat in the four primal cuts, were measured and used to evaluate the EMME and ultrasound backfat probe, alone and in combination, in predicting carcass merit. Value of prediction was measured as significant improvement in correlation over a base model (A/?2). After adjustment for live weight and treatment (diet, sex and housing) differences, the EMME alone was significant in predicting grade fat (A/?2 = 007), weight of the four untrimmed primal cuts (A/?2 = 0·03) and weights of ham (A/?2 = 0·04), lean (A/?2 = 0·17) and subcutaneous fat (A/?2 = 0·08). Backfat thickness alone was significant in predicting grade fat (AR2 = 0·21) and the weights of loin (AR2 = 0·03), ham (AR2 = 0·02), lean (AR2 = 0·09) and subcutaneous fat (AR2 = 0·42). Their combined information was superior in predicting fat thickness (AR2 = 0·24), weight of lean (AR2 = 0·21) and weight of subcutaneous fat (AR2 = 0·44). Similar results were obtained when treatment effects were ignored. Correlations of the EMME number with fat thickness, weight of total lean and total subcutaneous fat were 0·31, 0·49 and -0·30, respectively. Correlations of backfat thickness with grade fat, weight of total lean and total subcutaneous fat were 0·53, -0·35 and 0·72, respectively.

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A Comparison of the Hennessy Lamb Probe, Ruler Probe and Visual Fat Scores for Use in Sheep Carcass Classification

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600015506 ◽

1986 ◽

Vol 1986 ◽

pp. 39-39

Author(s):

J P Chadwick ◽

A J Kempster ◽

D L M Homer

Keyword(s):

Classification Scheme ◽

Subcutaneous Fat ◽

Carcass Composition ◽

Objective Measures ◽

List Type ◽

Type Number ◽

Meat Yield ◽

Visual Assessments ◽

Probe Measurements ◽

Better Than

1Visual assessments of subcutaneous fat cover are used in the Meat and Livestock Commission's Sheep Carcass Classification Scheme to estimate meat yield. (Details of the scheme have been given by Meat and Livestock Commission, 1980.) The scheme is operated in over 100 abattoirs and covers approximately 0.25 of the GB kill. Objective measures of fatness may improve the precision of predicting carcass composition, aid standardisation and stimulate the uptake of the scheme by creating greater confidence.2Previous MLC trials with either a simple Ruler Probe or equipment developed for use in pig carcass classification such as optical or automatic-recording probes have indicated only moderate success with sheep carcasses. The precision achieved with probe measurements was no better than visual scores, but additional precision resulted from combining both techniques (Kempster, Chadwick, Cue, Grantley-Smith, 1986).

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A caliper for determining carcass composition in live cattle and skin-on carcass

Australian Journal of Agricultural Research ◽

10.1071/ar9830825 ◽

1983 ◽

Vol 34 (6) ◽

pp. 825 ◽

Cited By ~ 2

Author(s):

ER Johnson ◽

CB Davis

Keyword(s):

Rectal Wall ◽

Carcass Composition ◽

Carcass Weight ◽

Fat Percentage ◽

Linear Measurements ◽

Muscle Weight ◽

Fat Thickness ◽

Thickness Measurements ◽

Skinfold Caliper ◽

Made In

A Harpenden Skinfold Caliper used to predict body density in man was modified for use in cattle. It was used to measure thickness of the anal fold, caudal fold and rectal wall in 34 live steers or their skinon carcasses (hot dressed weight 139-339 kg). The value of these measurements in determining carcass fat and carcass muscle was compared with that of 10th and 12th rib fat thickness measurements made in the carcass. Hot carcass weight was the best predictor of side fat weight and side muscle weight. Side fat percentage and side muscle percentage were most accurately predicted by 12th rib and 10th rib fat thickness, followed by live then single-shackle anal fold fat thickness. The three caudal fold measurements and rectal wall thickness were poor predictors. Addition of hot carcass weight to all linear measurements markedly improved the prediction of side fat weight and side muscle weight, but nor side fat percentage and, only marginally, side muscle percentage. Single-shackle anal fold fat thickness, slightly less accurate than the live measurement, was the most useful skin-on measurement. The spring-operated caliper described can be used to determine carcass fatness and carcass lean in live steers with an accuracy closely approaching that of 12th rib fat thickness in the carcass.

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