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

1983 ◽  
Vol 101 (1) ◽  
pp. 241-248 ◽  
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.

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

1986 ◽  
Vol 106 (2) ◽  
pp. 223-237 ◽  
Author(s):  
A. J. Kempster ◽  
J. P. Chadwick ◽  
D. D. Charles
Keyword(s):  
Subcutaneous Fat ◽  
Visual Assessment ◽  
Carcass Composition ◽  
Beef Breed ◽  
Percentage Unit ◽  
Wide Range ◽  
Fat Thickness ◽  
Substantial Bias ◽  
Visual Assessments ◽  
Thickness Measurements

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.

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

1983 ◽  
Vol 34 (6) ◽  
pp. 825 ◽  
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.

Comparison of the prediction of carcass components using fat thickness measurements in heifers and steers

1994 ◽  
Vol 34 (4) ◽  
pp. 435 ◽  
Author(s):  
ER Johnson
Keyword(s):  
Multiple Regression ◽  
Thickness Measurement ◽  
Carcass Composition ◽  
Carcass Weight ◽  
Regression Equations ◽  
Muscle Weight ◽  
Fat Thickness ◽  
Accuracy Of Prediction ◽  
Thickness Measurements ◽  
Simple Regression

Predictions of carcass composition based on anal fold and 12th rib fat thickness measurements were compared in 12 Hereford heifers and 12 Hereford steers. For carcass proportions, simple regression equations indicated that heifers had less muscle (2-3%), more fat (2.5-4%), and more bone (0.9%, 12th rib only). Empty liveweight did not improve the accuracy of prediction of any carcass component when added to anal fold fat thickness. Chilled carcass weight and 12th rib fat thickness slightly improved the accuracy of prediction of muscle and fat proportions compared with prediction using each measurement alone. Multiple regression indicated that the heifers had 2.5-3% less muscle and 34% more fat. For predictions of the weights of carcass components at a given fat thickness measurement, simple regression indicated that heifers had less muscle than steers (by about 6 kg), but for bone and fat the intercepts did not differ significantly between sexes. In multiple regression, empty liveweight contributed strongly to the predictions of weights of all 3 carcass components. In all regressions in which the weight of each of the 3 carcass components was regressed on a weight and a fat thickness measurement together, except for muscle and fat regressed on chilled carcass weight and 12th rib fat thickness, the fat thickness measurement failed to contribute significantly to prediction. Although chilled carcass weight and 12th rib fat thickness together contributed (P<0.01) to the prediction of muscle weight and fat weight, chilled carcass weight was the stronger contributor. Regression indicated that heifers had about 3 kg less muscle and 3.5 kg more fat than steers. Multiple regression analysis showed that heifers and steers had about the same weight of bone.

The use of non-carcass parts in the prediction of beef carcass composition on the slaughter floor

1979 ◽  
Vol 30 (4) ◽  
pp. 751 ◽  
Author(s):  
ER Johnson
Keyword(s):  
Connective Tissue ◽  
Thickness Measurement ◽  
Carcass Composition ◽  
Regression Equations ◽  
Appraisal System ◽  
Genetic Progress ◽  
Muscle Weight ◽  
Additional Information ◽  
Fat Thickness ◽  
Thickness Measurements

Ninety-five steers were used to develop a method of estimating the weights or percentages of the four carcass tissues—muscle, bone, fat and connective tissue—while the carcasses were still on the slaughter floor. From an investigation of a number of non-carcass parts it was found that three measurements could be used to estimate all four carcass components. The measurements were (a) short-cut tongue weight; (b) foreshanks weight; (c) hot side weight. Simple and multiple regression equations were developed to estimate the weights of muscle, bone and connective tissue in the chilled side, and the accuracy of the estimates was compared with that of recorded prediction methods. The most useful equations employed short-cut tongue weight and hot side weight to estimate total side muscle weight, and foreshanks weight to estimate both total side bone weight and total side connective tissue weight. Fat weight was estimated from hot side weight and the estimates of the weights of the other three carcass components. This technique was more accurate than the Australian Beef Carcase Appraisal System and Butterfield's equation, both of which use fat thickness measurement at the 10th rib. When fat thickness measurement was included in regression equations, the estimates of muscle weight and fat weight were slightly improved. Advantages of using the 'non-carcass parts' technique are as follows. All four major carcass components are predicted; the carcass components can be recorded as absolute weights or percentages of chilled side weight; chilled side components are predicted whilst the hot side is still on the slaughter floor; no commercial loss occurs in carcass, offals or by-products; all measurements used in prediction are weights; and fat thickness measurements may be included in the prediction. The additional information enables producers to make a more critical assessment of the nutritive performance and genetic progress of their herds.

An evaluation of three ultrasonic machines for predicting the body composition of live pigs of the same breed, sex and live weight

1982 ◽  
Vol 35 (2) ◽  
pp. 165-169 ◽  
Author(s):  
J. C. Alliston ◽  
A. J. Kempster ◽  
M. G. Owen ◽  
M. Ellis
Keyword(s):  
Live Weight ◽  
Thickness Measurement ◽  
The Body ◽  
Control Line ◽  
Large White ◽  
Precise Prediction ◽  
Fat Thickness ◽  
Prediction Residual ◽  
Thickness Measurements ◽  
Entire Male

ABSTRACTMeasurements of the m. longissimus and overlying fat at the last rib were taken on 39 live entire male pigs using three ultrasonic machines of differing complexity: Sonatest (simple A-mode machine), Scanogram (modified linear scanner) and Danscanner (‘real time’ scanner). Each machine had a different operator and interpreter. The pigs were from two lines of Large White, one selected for efficiency of lean-tissue gain (20 pigs) and the other a genetic control line (19 pigs). They were measured in the week prior to slaughter at approximately 90 kg live weight (91·4 (s.e. 4·4) kg).The analysis was pooled within line and the precision of carcass lean prediction at constant live weight examined for the three machines. Standard deviation of lean in carcass at equal live weight was 16·2 g/kg.A single fat thickness measurement taken by the Sonatest gave the most precise prediction (residual s.d. = 12·9 g/kg). Marginally poorer relationships were recorded for a similar measurement taken by the Scanogram (13·5 g/kg) and Danscanner (13·3 g/kg). Precision was not improved from the use of additional fat thickness measurements or, in the case of the scanning machines, from the addition of fat area over the m. longissimus or the area of the muscle itself. The results confirm that the Scanogram and Danscanner do not offer significant advantages over the simpler and cheaper Sonatest in the circumstances considered.

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.

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

1989 ◽  
Vol 48 (2) ◽  
pp. 427-434 ◽  
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.

An evaluation of the Hennessy Grading Probe and the SFK Fat-o-Meater for use in pig carcass classification and grading

1984 ◽  
Vol 1984 ◽  
pp. 87-87
Author(s):  
A J Kempster ◽  
J P Chadwick ◽  
D W Jones
Keyword(s):  
Classification Scheme ◽  
Optical Probe ◽  
Precise Prediction ◽  
Fat Thickness ◽  
Thickness Measurements

Fat thickness measurements taken laterally over the M. longissimus in the caudal rib region normally provide a more precise prediction of carcass lean content than other measurements suitable for use in classification and grading schemes. Such measurements are currently taken using the Danish optical probe (intrascope) in the national pig carcass classification scheme operated by MLC.

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

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

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

1982 ◽  
Vol 62 (3) ◽  
pp. 731-738 ◽  
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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