Elliotdale and crossbred lambs: growth rate, wool production, fat depth, saleable meat yield, carcass composition and muscle content of selected cuts

1992 ◽  
Vol 32 (4) ◽  
pp. 429 ◽  
Author(s):  
DL Hopkins ◽  
KD Gilbert ◽  
KL Pirlot ◽  
AHK Roberts

Growth and carcass parameters were studied for 62 second-cross lambs (Poll Dorset rams over Border Leicester x Merino ewes) and 55 purebred Elliottdale lambs. Second cross lambs grew faster (P<0.001) from weaning to the first slaughter time than Elliottdale lambs and consequently weighed more and had heavier carcasses. Elliottdale lambs produced significantly (P<0.001) more wool between birth and weaning. The slope of the relationship between GR (tissue depth over the 12th rib 110 mm from the midline) and carcass weight was 1.24 � 0.23 mm/kg for second cross lambs and 0.82 � 0.17 mm/kg for Elliottdale lambs, indicating the latter lambs were leaner at heavier weights. Measures of subcutaneous fat depth at the 5th/6th and 12th/13th ribs were similar when carcass weight differences were considered for a subsample of 21 second cross and 26 purebred Elliottdale lambs. Subjective assessment of fat distribution and carcass conformation by 2 assessors revealed a significant (P<0.001) difference between breeds; second cross lambs having a better conformation. Saleable meat yield, carcass composition, and muscle content of several cuts were determined for a subsample of lambs. At a common side weight of 8 kg there was no significant difference in saleable meat yield. At this weight, crossbred lambs had a significantly (P<0.05) higher muscle content (505 g/kg) than Elliottdale lambs (480 g/kg). Fat content was similar at 300 g/kg with crossbred lambs having significantly (P<0.05) less bone (190 g/kg) than Elliottdale lambs (2 10 g/kg). The legs of carcasses from crossbred lambs were shown to contain significantly more muscle than those of Elliottdales (206 v. 195 g/kg). Carcass weight explained some of the variation in weight of leg and forequarter muscle (r2 = 0.63 and 0.61). This was improved by including an assessment for conformation from 1 assessor (r2 = 0.69 and 0.64). Eye muscle area at the 12th rib did not add significantly to the prediction; it was not different between breeds, nor was its depth to width ratio different between breeds. The pH measurements of the M. longissimus thoracis et lumborum were similar between breeds.

1993 ◽  
Vol 33 (7) ◽  
pp. 825 ◽  
Author(s):  
D Perry ◽  
AP Yeates ◽  
WA McKiernan

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).


1993 ◽  
Vol 33 (3) ◽  
pp. 275 ◽  
Author(s):  
D Perry ◽  
WA McKiernan ◽  
AP Yeates

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.


Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 651 ◽  
Author(s):  
Addisu Hailu Addis ◽  
Hugh Thomas Blair ◽  
Stephen Todd Morris ◽  
Paul Richard Kenyon ◽  
Nicola Maria Schreurs

Prediction equations have been widely utilized for carcass classification and grading systems in older beef cattle. However, the equations are mostly relevant for common beef breeds and 18 to 24 month old animals; there are no equations suitable for yearling, dairy-origin cattle. Therefore, this study developed prediction models using 60 dairy-origin, 8 to 12 month old steers to indicate saleable meat yield from hind-legs, which would assist with carcass classification and grading. Fat depth over the rump, rib fat depth, and eye muscle area between the 12th and 13th ribs were measured using ultrasound, and wither height was recorded one week prior to slaughter. The muscles from the hind-leg were retrieved 24 h after slaughter. Prediction equations were modeled for the hind-leg muscles weight using carcass weight, wither height, eye muscle area, rump, and rib fat depths as predictors. Carcass weight explained 61.5% of the variation in hind-leg muscles weight, and eye muscle area explained 39.9% (p < 0.05). Their combination in multivariate analysis explained 63.5% of the variation in hind-leg muscles weight. The R2 of the prediction in univariate and multivariate analyses was improved when data were analyzed per age group. Additional explanatory traits for yearling steers, including body length, hearth girth, and muscle depth and dimensions measured using video image analysis scanning (VIAscan), could improve the prediction ability of saleable meat yield from yearling dairy beef steers across the slaughter age groups.


Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1884 ◽  
Author(s):  
Gertruida L. van Wyk ◽  
Louwrens C. Hoffman ◽  
Phillip E. Strydom ◽  
Lorinda Frylinck

Weaner male Boer Goats (BG; n = 36; 21 bucks and 15 wethers) and large frame Indigenous Veld Goats (IVG; n = 41; 21 bucks and 20 wethers) were raised on hay and natural grass ad libitum and the recommended amount of commercial pelleted diet to a live weight between 30 and 35 kg. Carcass quality characteristics (live weight, carcass weights, dressing %, chilling loss and eye muscle area) were measured. The right sides of the carcasses were divided into wholesale cuts and dissected into subcutaneous fat, meat and bone. Large frame Indigenous Veld Goat (IVG) wethers were slightly lighter than the IVG bucks with no significant difference observed between BG. Wethers compared to bucks had higher dressing %, subcutaneous fat % in all primal cuts, intramuscular fat %, kidney fat % and, overall, slightly less bone %. Some breed–wether interactions were noticed: IVG wethers were slightly lighter than the IVG bucks, but the IVG bucks tended to produce higher % meat compared to other test groups. Judged on the intramuscular fat % characteristics, it seems as if wethers should produce juicier and more flavorsome meat compared to bucks.


1992 ◽  
Vol 43 (4) ◽  
pp. 819 ◽  
Author(s):  
LP Thatcher ◽  
GM Gaunt

Sixty-five Poll Dorset x (Border Leicester/Merino) ewe lambs. were grown at pasture on one of four growth paths commencing at mean age of 24 weeks and a mean liveweight of 37-5 kg. These were, continuous growth between 24 and 34 weeks (HH), maximum possible growth for 6 weeks followed by weight loss for 4 weeks (HL), no gain for 6 weeks followed by rapid gain for 4 weeks (LH) and weight maintenance (LL). Lambs were slaughtered as soon as possible after LH and HL lambs were the same full weight. There were significant differences between treatments in average growth rate, liveweight, hot carcass weight (HCW) and dressing percentage. After adjustment for HCW, LH had significantly (P < 0.05) less omental and kidney fat than HH, and there was a strong tendency for less subcutaneous fat, intermuscular fat and a lower tissue depth over the twelfth rib (at the GR site). Eye muscle area was significantly larger in LH than HH, but this did not translate to a significant difference in dissectible 'soft tissue' measurement. The Warner Bratzler shear value for LL in the M. longissimus dorsi was significantly higher than LH and HH. There were no differences between treatments for pH, Warner Bratzler shear values of the M. semimembranosus, cooking loss, or the colour measurements using a Minolta chromameter of L* (lightness) or b* (yellowness). The difference in a* (redness) between HL and LH was significant. Warner Bratzler shear values for M. longissimus dorsi and M.semimembranosus were significantly higher at 4�C than 10�C. The a* was significantly higher at 10�C, but there were no differences between L* and b*. There were no interactions between the post-slaughter chilling regime and the pre-slaughter nutritional management. It was concluded that the growth path had little effect on meat quality unless the lamb had been continuously on a restricted diet. Therefore there was some potential for the use of growth paths to manipulate carcass composition, and further research into management systems at pasture is recommended.


1981 ◽  
Vol 32 (1) ◽  
pp. 171 ◽  
Author(s):  
JM Thompson ◽  
R Barlow

The effect of sire breed on the growth and development of carcass characteristics was examined in 104 steer carcasses, over the weight range of c. 300 to 600 kg liveweight. The carcasses were obtained from 28 straightbred Hereford, 27 Brahman x Hereford, 23 Simmental x Hereford and 26 Friesian x Hereford steers, which were grown on pasture and slaughtered in four groups when the Herefords weighed c. 270, 370, 470 and 570 kg liveweight. Changes in carcass characteristics with weight were examined by using the linear form of the allometric equation (log10Y = log10A+blog10X). As liveweight increased, the proportion of carcass in the body increased (b = 1.152). At the same liveweight, Brahman cross steers had heavier carcasses than the Hereford steers, which were heavier than either the Simmental or Friesian cross steers (P < 0.05). Fat thickness at the 12th-13th rib site, and kidney and channel fat weight both increased at a proportionally faster rate than carcass weight (b = 1.511 and 1 567 respectively). At the same carcass weight, Hereford and Brahman cross carcasses had a greater fat thickness than Simmental and Friesian cross carcasses (P i 0.05). Differences between sire breeds in kidney and channel fat weight were not significant (P > 0.05). C:rcass length and eye muscle area increased at a proportionally slower rate than carcass weight (b = 0.268 and 0.466 respectively). At the same carcass weight, Friesian cross carcasses were longer, and Simmental cross carcasses had a larger eye muscle area than the other breed crosses (P < 0.05). As total side weight increased, the proportions of subcutaneous and intermuscular fatAincreased (b = 1.554 and 1.535 respectively), and the proportions of muscle and bone decreased (b = 0.938 and 0.676 respectively). At the same side weight, the Hereford and Brahman cross carcasses had more subcutaneous fat than the Simmental and Friesian cross carcasses (P < 0.05). The Hereford carcasses had more intermuscular fat than the Simmental cross carcasses, which had more muscle than the other breed crosses (P < 0.05). Friesian cross carcasses had more bone than the Simmental crosses, with Brahman cross and Hereford carcasses having the least bone (P < 0.05). Brahman cross carcasses had a higher conformation score than the Simmental cross and Hereford carcasses, the Friesian cross carcasses having the lowest (P < 0.05). Samples of the M. longissimus from Brahman cross carcasses had a higher Warner-Bratzler shear force than samples from the other breed crosses (P < 0.05).


1995 ◽  
Vol 35 (2) ◽  
pp. 161 ◽  
Author(s):  
DL Hopkins ◽  
JSA Wotton ◽  
DJ Gamble ◽  
WR Atkinson

Carcass data were obtained for 172 lambs (86 ewes, 86 cryptorchids) of hot carcass weight (HCW) 16.2-28.7 kg and fat depth at the GR site (12th rib) 5-21 mm. Of these, 85 carcasses (42 ewe, 43 cryptorchid) were prepared into the full range of boneless, heavily trimmed cuts ('trim' lamb) and the remaining 87 (44 ewe, 43 cryptorchid) into traditional, trimmed bone-in cuts. Two methods of determining M. longissimus thoracis et lumborum area (EMA) produced strongly correlated results (r = 0.94; P<0.001). Conformation score using the EUROP system (1 is best, 5 is worst) was negatively correlated (r = -0.31 to -0.53; P<0.05) with measures of EMA and HCW, which were positively correlated (r = 0.64-0.71; P<0.001). Leg length was positively correlated (r = 0.36-0.76; P<0.001) with measures of EMA and HCW. Models were developed to predict the percentage yield of saleable cuts for carcasses prepared into a range of trim and traditional cuts. These identified GR as the most significant variable, so models based on GR were developed for each yield type. HCW and EMA significantly (P<0.05) improved the accuracy of estimated yield in addition to GR. By contrast, when HCW and measurements of subcutaneous fat depth over the eye muscle (FDC) were combined, EMA was not significant (P>0.05). For estimation of the percentage yield of traditional cuts, conformation score as given by an assessor significantly (P<0.05) improved the accuracy of estimation when combined with HCW and FDC. This model indicates that as conformation score increases, yield increases. Overall in terms of predicting yield, conformation score was of little value when combined with currently used carcass measures. There was a significant (P<0.05) effect of sex on the prediction of yield for 2 combinations of trim cuts that included the eye of loin. Sex also influenced (P<0.05) the prediction of yield based on traditional cuts. Where sex was significant, ewe lamb carcasses had less saleable meat by <0.5-1.0%, depending on yield type. For 4 of the trim cuts (boneless loin, eye of loin, fillet, shoulder blade), EMA added significantly (P<0.05) to the estimation of the proportions of the cuts; at constant carcass weight and fatness as indicated by GR, increases in EMA are predicted to lead to an increase in the proportion of loin cuts and a decrease in shoulder blade. For carcasses prepared into traditional cuts, EMA added significantly (P<0.05) to the estimation of leg, midloin, forequarter, and shank cuts. In all cases the coefficient was positive, indicating that increases in EMA would lead, at constant carcass weight and fatness (GR), to an increase in the proportion of these cuts in the carcass. The amount of variation (R2) explained for the individual trim cuts ranged from 0.08 to 0.72 using models that included independent variables HCW, GR, and EMA, and which accounted for the effect of sex. For traditional cuts the values ranged from 0.28 to 0.79.


1993 ◽  
Vol 57 (1) ◽  
pp. 65-72 ◽  
Author(s):  
R. Priyanto ◽  
E. R. Johnson ◽  
D. G. Taylor

AbstractThe effects of breed and feeding on the prediction of carcass fat and carcass muscle using rump ‘P8’ subcutaneous fat thickness were investigated in heavy-weight beef carcasses (277 to 512 kg). Hot side weight, eye muscle area and their combination added to fat thickness were evaluated as additional predictors. The predictions of carcass composition from grass-fed steers were validated on data from grain-fed steer carcasses. There were differences between breeds and feeding regimes in the level of tissue proportions at a given fat thickness, but no differences in regression slopes. Fat thickness alone was, therefore, not an accurate indicator of the proportions of side fat or side muscle in heavy-weight carcasses. In the grain-fed steers, the correlations between P8 and tissue proportions were relatively strong, and the addition of hot side weight and eye muscle area, alone or in combination, did not significantly improve the predictions. Conversely, in grass-fed steers where the relationships between carcass composition and fat thickness were weaker, the addition of hot side weight and eye muscle area made a significant contribution to prediction. In the predictions of tissue weights, hot side weight and eye muscle area when added to fat thickness, significantly contributed to the prediction of side muscle weight for both feeding systems. These three variables did not account for the observed differences between breeds or feeding regimes in the proportion or weight of fat, nor in the proportion of muscle; but they effectively eliminated these groups' differences in the estimation of muscle weight.


1982 ◽  
Vol 99 (2) ◽  
pp. 337-341 ◽  
Author(s):  
J. J. Bass ◽  
G. Winn ◽  
W. D. Paulsen

SUMMARYVery experienced livestock judges and three ultrasonic machines were compared for accuracy in predicting carcass composition.Sixty-four steers of mixed breed were visually scored for fatness and meat yield by seven judges. Subcutaneous fat depths over the eye muscle at the 13th rib were measured with three different ultrasonic devices prior to slaughter. There was little difference between the ultrasonic machines and the best visual estimates of fatness for predicting weight of commercial trimmed or total dissected fat. Visual estimates of meat yield were not as accurate as the judges' fat scores for predicting carcass composition.Subcutaneous fat depths measured by ultrasonics were shown to be as well related to carcass composition as the best judge's fat scores.


1980 ◽  
Vol 31 (3) ◽  
pp. 315-319 ◽  
Author(s):  
J. D. Wood ◽  
H. J. H. MacFie

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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