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.

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.

The estimation of pig carcass composition from different measurements with special reference to classification and grading

1985 ◽  
Vol 41 (3) ◽  
pp. 383-391 ◽  
Author(s):  
A. Diestre ◽  
A. J. Kempster
Keyword(s):  
Optical Probe ◽  
Thickness Measurement ◽  
Carcass Composition ◽  
Carcass Weight ◽  
Regression Equations ◽  
Independent Variables ◽  
Evaluation Scheme ◽  
Fat Thickness ◽  
The Stability ◽  
Cut Surface

AbstractData for 1002 pigs slaughtered between 1979 and 1982 from the Meat and Livestock Commission's Commercial Pig Evaluation scheme were used to examine the relative precision of different measurements for predicting carcass lean concentration. The sample covered the main market weights in Britain and comprised gilts and barrows. The overall means of carcass weight and lean concentration were 66·1 (s.d. 20·00) kg and 499 (s.d. 44·2) g/kg. Predictors were examined when used in addition to carcass weight.Of the measurements taken on the intact or centre-split carcass, fat thickness measured by optical probe 65 mm from the dorsal mid line over the m. longissimus at the last rib was the most precise predictor of lean concentration (residual s.d. = 24·6 g/kg). The precision was improved significantly when a mid-line loin fat thickness measurement was added (residual s.d. = 23·7). The stability of the selected regression equations was examined by applying them to data for three other sets of carcasses (totalling 489 carcasses) sampled from commercial abattoirs between 1975 and 1983. Biases (predicted minus actual lean concentrations) ranged from +13 to −25 g/kg.Among the measurements taken on the cut surface at the last rib, fat thickness 8 cm from the dorsal mid line was the most precise predictor (residual s.d. = 22·4 g/kg). The precision was improved significantly when m. longissimus depth was added (residual s.d. = 20·3 g/kg). Prediction bias with these measurements was similar to that recorded with the intact or split-carcass measurements. In both cases, bias tended to increase with the number of independent variables in the prediction equations.

An evaluation of the Hennessy and Chong Fat Depth Indicator, and the Ulster Probe, for use in pig carcass classification and grading

1981 ◽  
Vol 33 (3) ◽  
pp. 319-324 ◽  
Author(s):  
A. J. Kempster ◽  
J. P. Chadwick ◽  
D. W. Jones ◽  
A. Cuthbertson
Keyword(s):  
Standard Deviation ◽  
Multiple Regression ◽  
Lumbar Vertebrae ◽  
Optical Probe ◽  
Carcass Weight ◽  
Residual Standard Deviation ◽  
Fat Thickness ◽  
Prediction Residual ◽  
Thickness Measurements ◽  
Cut Surface

ABSTRACTThe Hennessy and Chong Fat Depth Indicator and the Ulster Probe automatic recording instruments developed for measuring fat thickness were tested against the optical probe for use in pig carcass classification and grading.Fat thickness measurements were taken using each probe 60 mm from the dorsal mid-line over the m. longissimus at the positions of the 3rd/4th lumbar vertebrae, 3rd/4th last ribs and last rib on a total of 110 hot carcasses covering the range of market weights in Great Britain. The standard deviation of carcass lean proportion at equal carcass weight was 35·4 g/kg.The instruments differed little in the precision of carcass lean proportion prediction: residual standard deviation (g/kg) for the multiple regression with carcass weight and the best individual fat measurement for each probe were: last rib optical probe, 22·1; last rib Ulster Probe, 22·7; and 3rd/4th last rib Fat Depth Indicator, 21/6. Residual standard deviation (g/kg) for carcass lean proportion prediction from carcass weight and all three fat measurements in multiple regression were 21·3 optical probe, 21·3 Ulster Probe and 201 Fat Depth Indicator.Similar mean fat measurements were obtained from the optical probe and Fat Depth Indicator, and for these instruments, but to a lesser extent for the Ulster Probe, the regression relationships with each other and with fat thickness measurements taken on the cut surface of the cold carcass were also similar.The differences recorded in precision are unlikely to be sufficiently important to influence the choice of one probe rather than another.

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.

Comparison of twelfth rib and rump fat thickness measurements for predicting commercial beef yield in local market carcasses

1987 ◽  
Vol 27 (5) ◽  
pp. 613 ◽  
Author(s):  
ER Johnson
Keyword(s):  
Regression Analysis ◽  
Multiple Regression Analysis ◽  
Multiple Regression ◽  
Carcass Weight ◽  
Standard Errors ◽  
Local Market ◽  
Lower Standard ◽  
Fat Thickness ◽  
Similar Accuracy ◽  
Thickness Measurements

The abilities of 12th rib and rump fat thickness measurements to predict yield of saleable beef were compared in 40 Hereford steer carcasses weighing 173-235 kg. Saleable beef yield and fat trim were significantly related (P< 0.05) to all 4 fat thickness measurements studied, rump P8, rump sacral crest, 12th rib (all cold) and 12th rib (hot). Rump measurements generally, had slightly lower standard errors of estimate than the 12th rib measurements in predicting the weights and percentages of saleable beef yield and fat trim. Rump P8 predicted saleable beef yield weight, saleable beef yield percentage, fat trim weight and fat trim percentage with means (� s.e.) of 72.55 (� 6.69) kg, 70.52 (� 0.72)%, 7.23 (� 0.86) kg and 6.99 (� 0.68)%, respectively. Multiple regression analysis showed that the addition of hot carcass weight or cold carcass weight as the second regressor resulted in predictions of similar accuracy. Quadratic analyses indicated that weight or percentage of cuts, manufacturing trim, saleable beef yield and fat trim were linearly related to 12th rib (cold) fat thickness and to P8 fat thickness.

Prediction of the commercial yield of beef from carcasses destined for the Japanese market by using measurements from the carcass and non-carcass parts

1989 ◽  
Vol 29 (4) ◽  
pp. 489 ◽  
Author(s):  
ER Johnson ◽  
B Ball
Keyword(s):  
Bos Indicus ◽  
Thickness Measurement ◽  
Regression Coefficients ◽  
Regression Equations ◽  
Site Location ◽  
Hereford Cattle ◽  
Percentage Yield ◽  
Fat Thickness ◽  
Commercial Yield ◽  
Thickness Measurements

Yield of saleable beef was predicted in 4 genotypes of bullocks (Hereford, Brahman, Brahman x Hereford and Simmental x Hereford). Simple and multiple regression equations were used to determine how well 4 fat thickness measurements (12th rib and rump measurements SC3 SC5 and SC7) individually, with or without the inclusion of hot side weight, foreshanks weight and short cut tongue weight predicted the yields of saleable beef. Each of the 4 fat thickness measurements (alone) predicted percentage yield of saleable beef with low r.s.d.'s at the means. The regression coefficients for the 4 fat thickness measuring sites were negative and significant in the Hereford, Brahman and Brahman x Hereford groups. In the Simmental x Hereford cattle, the regression coefficients for the rump sites (SC3, SC5 and SC7) were positive but significant only in SC5 which had the lowest r.s.d. (1.56%) of all sites. Twelfth rib fat thickness, with a common regression coefficient for all 4 genotypes (P<0.01) and an r.s.d. of 1.81%, was the next most useful fat thickness measurement. The addition of hot side weight improved the prediction of percentage saleable beef yield at the SC3 and SC5 sites, but not in the pure-bred Brahman bullocks. For populations that include British, European and Bos indicus cattle and their crosses, SC5 fat thickness (alone) was the best determinant of percentage yield of saleable beef. Neither quadratic analyses nor the addition of foreshanks weight or short-cut tongue weight to the fat thickness measurements improved the accuracy of linear regression in any of the 4 genotypes. The errors in prediction of percentage yield of saleable beef (0.28-0.67%) attributable to incorrect rump site location (of up to 4.0 cm) are unlikely to jeopardise the commercial value of yield of saleable beef predicted from measurements made on the rump. Whilst the Brahman and Brahman x Hereford cattle produced high-yielding carcasses for the Japanese chilled beef market and the Simmental x Hereford cattle, by judicious management could equal this yield, carcass yields of the Hereford cattle were about 4-5% lower at all levels of fat thickness. The ability of Hereford cattle to satisfy this market, economically, is seriously questioned.

The electronic prediction of commercial yield and lean content in pig carcasses

1983 ◽  
Vol 37 (1) ◽  
pp. 33-40 ◽  
Author(s):  
S. D. M. Jones ◽  
C. R. Haworth
Keyword(s):  
North American ◽  
Subcutaneous Fat ◽  
Carcass Weight ◽  
Regression Equations ◽  
Digital Readout ◽  
Fat Thickness ◽  
Commercial Yield ◽  
Pig Carcasses ◽  
Thickness Measurements ◽  
Lean Weight

ABSTRACTOne hundred and fourteen pig carcasses were measured within 1 h of slaughter for fat thickness at three locations using the SFK Fat-O-Meater. The three fat thickness locations were the last rib and 3rd and 4th last ribs measured 70 mm from the dorsal mid-line over the m. longissimus, and the lumbar fat thickness which was recorded on the anterior face of the m. glutens medius on the dorsal mid-line of the split carcass. Lean depth measurements were also recorded at the last rib and 3rd and 4th last ribs for all carcasses. After overnight chilling the leanness of each carcass was estimated using an EMME SA-1 machine. The carcasses were then separated into the major tissues. The weight of trimmed North American commercial joints (standard of 6 mm subcutaneous fat) and their lean content were best predicted by half carcass weight (residual s.d. = 0·78 and 1·23 kg respectively), whereas the EMME machine readings alone had low precision (residual s.d. = 1·51 and 1·41 kg respectively). The proportion of North American commercial joints in a carcass and their lean content were best predicted by lumbar fat (residual s.d. = 16·5 and 25·8 g/kg). The digital readout of lean content provided by the EMME machine appeared to be more related to carcass weight than lean weight, as residual s.d. for regressions increased when the overall sample was divided into two weight classes. Multiple regression equations indicated that half carcass weight and fat thickness measurements gave the best precision to predict joint and lean weights, whereas fat thickness and lean depth measurements gave the best prediction of carcass joint and lean proportions.

Prediction of beef carcass composition from organs and tissues of the non-carcass parts

1984 ◽  
Vol 102 (3) ◽  
pp. 511-516 ◽  
Author(s):  
E. R. Johnson ◽  
M. K. Vidyadaran
Keyword(s):  
Standard Deviation ◽  
Carcass Composition ◽  
Carcass Weight ◽  
Residual Standard Deviation ◽  
Fat Depots ◽  
Fat Thickness ◽  
Accuracy Of Prediction ◽  
Slight Advantage ◽  
Beef Carcass

SummaryIndividual muscles, individual bones and fat depots from the non-carcass parts (head, foreshanks and tail) of 40 steers (chilled carcass weight 142–174 kg) were studied in an attempt to predict carcass composition more accurately than in an earlier study where the crude non-carcass parts, head, tongue, foreshanks and hindshanks were used.The technique did not improve the accuracy of prediction of muscle or bone. Carcass fat, which was calculated by difference in the earlier study, was predicted more accurately using intermandibular fat weight (requiring 3–4 min to obtain) plus fat thickness at the 12th rib. However, the accuracy of this prediction (carcass fatness range 14·0–33·6%, residual standard deviation 1·98%) was no greater than that using chilled side weight plus fat thickness at the 12th rib.Careful dissection and trimming of anatomical entities from the non-carcass parts therefore offered a slight advantage only in the prediction of carcass components over existing techniques.Substitution of hot side weight for chilled side weight, and sacral crest fat thickness for fat thickness at the 12th rib did not lead to a loss in the accuracy of prediction of muscle, bone or fat.

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