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.

Carcass composition in four sheep breeds: the importance of type of breed and stage of maturity

1980 ◽  
Vol 30 (1) ◽  
pp. 135-152 ◽  
Author(s):  
J. D. Wood ◽  
H. J. H. MacFie ◽  
R. W. Pomeroy ◽  
D. J. Twinn
Keyword(s):  
Subcutaneous Fat ◽  
Carcass Composition ◽  
Carcass Weight ◽  
Relative Growth ◽  
Fat Depots ◽  
Intermuscular Fat ◽  
The Mean ◽  
Total Fat ◽  
Omental Fat ◽  
Mature Size

ABSTRACTIn order to investigate the effects of type of breed on carcass composition, an examination was made of 361 lambs from four breeds: Clun Forest and Colbred (termed ewe breeds); and Suffolk and Hampshire (termed ram breeds). The animals were in four carcass weight groups averaging 15, 17, 19 and 21 kg.Percentage subcutaneous fat was influenced more by carcass weight than by breed, whereas both carcass weight and breed had similar effects on percentage lean. At the mean carcass weight of 18 kg, Colbreds, the leanest breed, had a similar value for percentage lean (about 57 % of carcass tissue weight) to the carcasses over all breeds weighing 15 kg; and Cluns, the fattest breed, had a similar value (about 54%) to those weighing 21 kg. Since the ram breeds were intermediate in composition between the two ewe breeds there was no effect of type of breed on carcass composition. The breed differences were related to eventual mature size and to the stage of maturity at each carcass weight, as judged by body length and bone weight measurements. However, Colbreds were bigger and leaner than published estimates of their mature weight suggested. Humerus weight was a good predictor of lean or total fat weight, explaining 83 % ofvariation when used as a predictor along with carcass weight.Type of breed had a marked effect on internal fat deposition, the ewe breeds having heavier weights of both kidney knob and channel fat (KKCF) and caul fat (omental fat) than the ram breeds; and on the length oflimb bones, the ewe breeds having longer but thinner bones than the ram breeds. The order of the relative growth of the tissues and fat depots was: subcutaneous fat > caul fat > KKCF > intermuscular fat > lean > bone. Therefore, the internal fat depots were later maturing than intermuscular fat.The percentage of prime cuts in the carcass was not affected by carcass weight. Colbreds had significantly lower values than the other breeds. Suffolks had the lowest lean to bone ratio.

Studies of fat distribution in the bovine carcass. I. The partition of fatty tissues between depots

1972 ◽  
Vol 23 (2) ◽  
pp. 381 ◽  
Author(s):  
HR Johnson ◽  
RM Butterfield ◽  
WJ Pryor
Keyword(s):  
Subcutaneous Fat ◽  
Distribution Patterns ◽  
Fat Distribution ◽  
Intramuscular Fat ◽  
Carcass Weight ◽  
Fatty Tissue ◽  
Fat Depots ◽  
Intermuscular Fat ◽  
Total Fat ◽  
Definition Of

(1) Total side fat (total dissected fat plus intramuscular fat) was examined in 23 bovine carcasses in four weight ranges. (2) The partition of fatty tissue between five depots revealed relative rises in intermuscular and subcutaneous depots and relative declines in intramuscular, kidney, and channel fats with increasing carcass weight. (3) Intermuscular and subcutaneous fats reached high levels relative to total side fat at different stages. Intermuscular fat rose quickly to c. 45.0% of total side fat at about 2.0 kg total side fat (c. 56 days) whilst subcutaneous fat reached 29.0% at c. 13.0 kg total side fat (c. 270 days). (4) Intramuscular fat did not show an increase relative to total side fat as carcass weight increased. Its contribution to total fat was greatest in the lightest sides and reached a minimal value at c. 13.0 kg total side fat, which it maintained thereafter. (5) All regressions of the weight of five fat depots on total side fat were highly significant (P < 0.01). (6) There appears to be a need for precise definition of fat distribution patterns in breeds and strains of cattle in order that carcasses of optimum composition might be produced.

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.

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).

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).

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.

Carcass composition of the water buffalo (Bubalus bubalis)

1972 ◽  
Vol 23 (5) ◽  
pp. 905 ◽  
Author(s):  
DD Charles ◽  
ER Johnson
Keyword(s):  
Weight Distribution ◽  
Subcutaneous Fat ◽  
Fat Distribution ◽  
Bubalus Bubalis ◽  
Carcass Composition ◽  
Muscle Weight ◽  
Anatomical Dissection ◽  
Intermuscular Fat ◽  
Intrinsic Muscles ◽  
Total Muscle

(1) Six buffalo bulls 14–48 months old were slaughtered and subjected to detailed anatomical dissection. (2) The dressing percentage of 55.2 was greater than that in cattle of similar carcass fatness (10.6). (3) Muscle constituted 37.1% of empty liveweight. (4) The carcasses had a high proportion by weight of muscle (68.6%), a low proportion of bone (17.3%), and a low proportion of fat (10.6%) relative to the proportions found in steer carcasses of similar muscle plus bone weights or total dissected fat percentages. (5) A study of muscle weight distribution showed that the spinal muscle group formed a lesser proportion of total muscle than in bovine steers, while the muscles of the proximal forelimb, those of the thorax passing onto the forelimb, and the intrinsic muscles of neck and thorax formed a greater proportion. The possibility of a sex effect on muscle weight distribution was discussed. (6) Fat distribution featured a high proportion of intermuscular fat relative to subcutaneous fat, and the proportions of kidney and channel fats were greater than those encountered in comparable bovine steer carcasses.

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.

Fat distribution and indices of carcass composition in Coats Island caribou (Rangifer tarandus groenlandicus)

1987 ◽  
Vol 65 (2) ◽  
pp. 368-374 ◽  
Author(s):  
J. Z. Adamczewski ◽  
C. C. Gates ◽  
R. J. Hudson
Keyword(s):  
Rangifer Tarandus ◽  
Gastrocnemius Muscle ◽  
Subcutaneous Fat ◽  
Fat Distribution ◽  
Carcass Composition ◽  
Allometric Relationships ◽  
Muscle Weight ◽  
Fat Depots ◽  
Kidney Fat ◽  
Rangifer Tarandus Groenlandicus

Twenty-seven barren-ground caribou (Rangifer tarandus groenlandicus) carcass sides were dissected on Coats Island, Northwest Territories, Canada, to calibrate indices of dissectible fat, muscle, and bone. Carcass muscle weight was accurately predicted from weight of the gastrocnemius muscle (In (carcass muscle, kg) = −2.791 + 1.071 In (gastrocnemius, g); r2 = 0.98), and carcass bone weight was accurately predicted from weight of the femur (In (carcass bone, kg) = −4.878 + 1.137 In (femur, g); r2 = 0.98). These allometric relationships held for calves and adults and for animals gaining and losing fat. The subcutaneous, intermuscular, pelvic, and internal omental and perirenal fat depots were weighed for each of 23 animals. The intermuscular and subcutaneous depots were largest and subcutaneous fat increasingly predominated at advanced fatness. Total dissectible fat in the five depots was most accurately predicted from depth of back fat and weight of kidney fat (dissectible fat (kg) = −0.178 + 1.058 depth of back fat (cm) + 24.147 kidney fat (kg); r2 = 0.98) and the regression was unaffected by age or condition. Comparison with similar studies suggests that such within-tissue relationships may be valid for all subspecies of Rangifer.

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