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.

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.

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.

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.

A comparison of different predictors of the lean content of pig carcasses 1. Predictors for use in commercial classification and grading

1979 ◽  
Vol 28 (1) ◽  
pp. 87-96 ◽  
Author(s):  
A. J. Kempster ◽  
D. G. Evans
Keyword(s):  
Cervical Vertebrae ◽  
Lumbar Vertebrae ◽  
Optical Probe ◽  
Precise Prediction ◽  
Fat Thickness ◽  
Pig Carcasses ◽  
Thickness Measurements ◽  
Carcass Measurement ◽  
Weight Groups ◽  
Probe Measurements

ABSTRACTCarcass measurement and dissection data for 1176 pigs were used to examine the suitability of different measurements for predicting carcass lean percentage in commercial classification and grading. Three carcass weight groups with means of 47, 72 and 93 kg, were analysed separately. Similar results were obtained and those for the 72 kg group are given in this abstract. The s.d. of percentage carcass lean in this group was 3·84. Visual conformation score, carcass length and m. longissimus depth were valueless as predictors (residual s.d. of carcass lean percentages were 3·84, 3·77 and 3·80 respectively). Fat thickness measurements taken on the exposed surface of the split carcass provided a less precise prediction (best residual s.d.=2·89) than fat measurements taken over the m. longissimus using the optical probe (best residual s.d. = 2·20). The probe measurements were taken 6·5 cm from the dorsal mid line at fixed positions along the carcass from 4/5th cervical vertebrae to the 5/6th lumbar vertebrae. Precision of prediction showed a regular pattern with highest levels at the last rib (the P2 position currently used in the Meat and Livestock Commission classification scheme) and at the 13th rib, with lower values anteriorly and posteriorly. These two measurements in multiple regression were more precise than any other pair of measurements for predicting both percentage carcass lean (residual s.d. = 2·16) and the lean percentage in individual primal joints.

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.

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.

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.

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 value of shape as a predictor of carcass composition in pigs from different breeding companies

1981 ◽  
Vol 33 (3) ◽  
pp. 313-318 ◽  
Author(s):  
A. J. Kempster ◽  
D. G. Evans
Keyword(s):  
Standard Deviation ◽  
Fat Content ◽  
Carcass Composition ◽  
Equal Weight ◽  
Large White ◽  
Residual Standard Deviation ◽  
Minimum Residual ◽  
Fat Thickness ◽  
White Control ◽  
Small Improvement

ABSTRACTCarcass data for a total of 1385 pigs from years 3 to 6 of the Meat and Livestock Commission's Commercial Pig Evaluation were used to examine the value of different shape assessments as predictors of carcass composition, when used in addition to carcass weight and fat thickness over the m. longissimus at the head of the last rib (P2). The sample comprised pigs from 13 breeding companies and a purebred Large White control.The standard deviation of carcass lean proportion at equal weight and P2 was 24·5 g/kg. The addition of carcass length or visual conformation assessments (five-point scales) provided a small improvement in precision (minimum residual standard deviation = 24·2 g/kg). This improvement was associated with a reduction in the variation of lean to bone ratio.The addition of an effect for breeding company to weight and P2 improved the precision substantially (residual standard deviation = 23·1 g/kg). The improvement was due mainly to the identification of differences in carcass fat content, there being a range of 30g/kg in carcass fat content between companies at equal weight and P2.There was a further small improvement in precision from the addition of conformation assessments to weight, P2 and company (minimum residual standard deviation = 22·9 g/kg).The study confirms earlier results which indicate that shape assessments are of limited value as predictors in the British pig population, due mainly to limited variation in lean to bone ratio. It also indicates that significant variation exists between companies in fat content at equal P2 and weight which is not explained by shape assessments.

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.

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