Growth and carcass composition of second-cross lambs. 1. Effect of sex and growth path on pre- and post-slaughter estimates of carcass composition

2001 ◽  
Vol 52 (8) ◽  
pp. 859 ◽  
Author(s):  
D. G. Hall ◽  
A. R. Gilmour ◽  
N. M. Fogarty ◽  
P. J . Holst ◽  
D. L. Hopkins

Carcass composition was estimated for 2316 second-cross lambs sired by 20 Poll Dorset rams over 2 years. The lambs were separated into ewes or cryptorchids at weaning with half of each sex group grown at a fast rate from weaning to slaughter at 40 kg liveweight for ewes or 48 kg for cryptorchids. The other half of each sex group was grown at a slower rate to the same slaughter weight 10–13 weeks later. Cryptorchids had fat scores about 0.4–1 unit lower and ultrasound C fat depths (45 mm from the mid-line over the 12th rib) about 0.8–1.3 mm less than ewes at the same liveweight. The carcass measures unequivocally showed that at the same carcass weight, fast-growing lambs were fatter than slow-growing lambs in both years and for both sexes. The average differences were 1.5 mm GR (total tissue depth 110 mm from the mid-line of the carcass over the 12th rib) and 1.4 mm C fat depth. Fat measurements on live lambs showed fast-growth cryptorchids were fatter than slow-growth cryptorchids; however, results for ewes were inconclusive. Slow growth to increase leanness needs to be evaluated against prevailing costs of lamb production and seasonal variation in prices. The correlations among and between live measures and carcass measurements of fatness were relatively low. The highest live to carcass R 2 values were ultrasound C fat depth with carcass C fat depth (0.36) and with the AUS-MEAT probe GR (0.34). There is a need to identify the best live lamb predictors of carcass composition.

2002 ◽  
Vol 53 (12) ◽  
pp. 1341 ◽  
Author(s):  
D. G. Hall ◽  
A. R. Gilmour ◽  
N. M. Fogarty ◽  
P. J. Holst

Growth and carcass performance of 2316 ewe and cryptorchid second-cross lambs over 2 years was related to the LAMBPLAN estimated breeding values (EBVs) of their sires. The lambs (56–156 per sire) were sired by 20 Poll Dorset rams from one stud, which were selected to represent a range of EBVs for growth rate and leanness. Half of each lamb sex group was grown at a fast rate from weaning to slaughter at 40 kg liveweight for ewes or 48 kg for cryptorchids. The other half was grown at a slower rate to the same slaughter weights, 10–13 weeks later. Lamb measurements included liveweight approximately every 21 days to slaughter, and fat and muscle depth on live lambs using ultrasound and carcass fat depth. The regressions of lamb weight on sire EBV for weight increased as the lambs aged and were 0.243 ± 0.124 for fasted weight pre-slaughter and 0.158 ± 0.064 for carcass weight. Live lamb C fat depth (45 mm from the mid-line over the 12th rib), carcass C fat depth, and carcass GR (total tissue depth 110 mm from the mid-line of the carcass over the 12th rib) were all related to sire EBV for fat. The regression values for ultrasound C fat depth and carcass GR of 0.156 ± 0.049 and 0.366 ± 0.159 on the sire EBV for fat (mm/mm EBV) were higher than the expected values. The results demonstrate that over a range of sires, 2 years, 2 sexes, and different nutrition regimes there are significant advantages in progeny weight and leanness if sires are selected for high EBVs for weight and leanness.


2009 ◽  
Vol 49 (6) ◽  
pp. 504 ◽  
Author(s):  
B. L. McIntyre ◽  
G. D. Tudor ◽  
D. Read ◽  
W. Smart ◽  
T. J. Della Bosca ◽  
...  

Growth, carcass characteristics and meat quality of the steer and heifer progeny of autumn (AC: March–April) and winter (WC: June–July) calving cows following weaning in January in each of 3 years (2003–05) were measured. The cows were mated to sires with a high estimated breeding value for either retail beef yield (RBY), intramuscular fat (IMF) or both RBY and IMF. After weaning, the progeny entered one of three growth paths until slaughter at an average steer liveweight of 500 kg: (i) fast – fast growth from weaning on a high concentrate feedlot diet; (ii) slow – slow growth from weaning (~0.6 kg/day) to 400 kg liveweight followed by growth at over 1 kg/day on high quality pasture; or (iii) comp. – 10% weaning weight loss, immediately after weaning followed by compensatory or rapid growth of over 1 kg/day on high quality pasture. Steers on the fast growth path had higher (P < 0.001) P8 fat thickness than those on the slow or comp. growth paths whereas heifers on the fast growth path only had higher (P < 0.001) P8 fat thickness than those on the slow growth path. Animals on the fast growth treatment had higher (P < 0.001) levels of IMF% than the slow animals which were higher (P < 0.001) than the comp. growth treatment. AUS-MEAT and US marbling scores were not different among growth paths. Animals finished on the fast growth path had a lower (P < 0.001) RBY% than those on either the slow or comp. growth paths. The RBY-sired progeny had higher (P < 0.001) finishing liveweight and hot standard carcass weight than either RBY and IMF or IMF-sired animals. IMF-sired progeny had higher (P < 0.01) rib fat thickness than either RBY or RBY- and IMF-sired animals. There was also a similar trend for P8 fat thickness but the effects were not significant. The RBY-sired animals had lower AUS-MEAT marbling scores (P < 0.01), US marbling scores (P < 0.001) and levels of IMF% (P < 0.01) than either of the other two sire treatments. RBY-sired animals also had higher (P < 0.001) estimated RBY% than those from the IMF sires while those by RBY and IMF sires were intermediate and not significantly different from either. Calving time had little influence on most carcass characteristics. However, WC animals tended to be fatter and have higher marbling scores than AC animals. The IMF% was higher (P < 0.01) in WC animals from RBY and IMF sires than in the corresponding AC animals. Heifers had lighter slaughter liveweight, carcass weight, were fatter and had higher marbling scores than steers. Heifers also had lower (P < 0.001) RBY% than the steers. Ossification scores for heifers were higher (P < 0.001) than for steers by ~30 units in AC calves and by 20 units in WC calves. The results of this experiment confirm the effectiveness of using sires with high estimated breeding value for the required characteristics in producing the desired improvements in the progeny. The absence of any interactions of sire type with growth path indicates that differences between sire types will be similar regardless of environmental conditions. Animals raised on a faster growth path after weaning produce carcasses with more fat and more IMF% than those grown on slower growth paths.


1996 ◽  
Vol 76 (1) ◽  
pp. 49-53 ◽  
Author(s):  
S. D. M. Jones ◽  
W. M. Robertson ◽  
M. A. Price ◽  
T. Coupland

A total of 281 lamb carcasses covering three weight groups (18–22.9, 23–25.9 and 26–30 kg) and fatness (< 3 mm, 3–5 mm and > 5 mm) were used to determine the usefulness of several carcass measurements for predicting saleable meat yield. Carcasses were measured for fat and muscle depth, 3–4 cm from the mid-line between the 10th and 11th ribs, 12th and 13th ribs and immediately adjacent to the 13th rib using a Hennessey Grading Probe. This technique also determined total tissue depth at 11 cm from the mid-line between the 10th and 11th and 12th and 13th ribs. The depth of tissues over the 12th rib 11 cm from the mid-line was measured with a ruler. Carcasses were also visually assessed for muscle development (conformation score) on a 5-point scale (1 = thinly fleshed; 5 = thickly fleshed). All carcasses were fabricated into primal cuts which were trimmed to 5 mm of fat and deboned to provide an estimate of saleable meat yield. Ewe lamb carcasses had a higher proportion of kidney fat than wethers in all weight and fat groups (which ranged from 2.6 to 17.9 g kg−1 carcass weight). Saleable meat yield decreased as carcasses became fatter, whereas weight group had little influence on saleable meat yield within a fat group. Ewe lamb carcasses had lower saleable meat yields than wether lamb carcasses, mainly because of their higher amounts of kidney fat. A ruler measurement of tissue depth over the 12th rib combined with carcass conformation score provided the most precise prediction (R2 = 0 61; RSD 17.1) of saleable meat yield. It was concluded that a simple manual system based on these two measurements provided an adequate prediction of saleable meat yield. The accuracy of the procedure would be increased by excluding kidney fat from carcass weight for the prediction of saleable meat yield. Key words: Lamb, carcass, composition, probe, fat, grade


1974 ◽  
Vol 83 (1) ◽  
pp. 79-85 ◽  
Author(s):  
D. R. Williams ◽  
R. W. Pomeroy ◽  
J. M. Harries ◽  
P. O. Ryan

SUMMARYThe data described in Part I of this series (Pomeroy et al. 1974) were analysed by regression methods, to see how, and how well, estimation of total carcass composition (simplified to bone, lean and fat) can be achieved in situations where the beef side cannot be fully dissected, but can be measured as an intact side, quartered and the cut surface photographed, or where sample joints can be dissected. Equations are given, based on the largest group (Group II, 72 animals) of the three previously described, and the advantages to be gained from quartering the carcass, photographing the cut surface, and dissecting a sample joint are quantified. These equations have been tested by applying them to the other two groups, I and III of 30 and 43 animals.


1991 ◽  
Vol 71 (3) ◽  
pp. 633-643 ◽  
Author(s):  
A. P. Sather ◽  
S. D. M. Jones ◽  
A. K. W. Tong

Data on 42 halothane-sensitive pigs (HSL, nn-genotype), 169 Lacombe pigs (LAC, NN-genotype), 41 crossbred pigs (XBD, Nn-genotype), and 72 Yorkshire pigs (YRK, NN-genotype) representing 145 gilts and 179 castrates, were obtained over the liveweight range from 74.0 to 134.5 kg (average 105 kg) to examine the effect of genotype, gender and slaughter weight on the composition of the four lean cuts (ham, loin, picnic and butt). Gilts had a greater proportion of dissectible lean from lean cuts than castrates (557 ± 2.8 vs. 525 ± 2.6 g kg−1). The HSL pigs had the highest and LAC pigs the lowest commercial dressing percentage, increasing respectively from 85.3 to 86.0% and 79.7 kg to 82.6% as slaughter weight increased from 80 to 130 kg. Corresponding figures for XBD and YRK pigs, were 82.5 to 85.4 and 80.6 to 84.6%, respectively. Dissectible lean from lean cuts from 65-kg carcasses was 606, 525, 536 and 575 g kg−1 for HSL, XBD, LAC and YRK pigs, respectively. Corresponding figures for 85-kg and 105-kg carcasses were 574, 525, 515, and 555 g kg−1 and 542, 525, 494, and 535 g kg−1, respectively from HSL, XBD, LAC and YRK pigs. LAC and YRK pigs, each with exclusively NN-genotypes but differing in composition of lean cuts, maintained their relative differences in composition over the weight range studied. Heterogeneity of slopes for changes in proportion of lean in the lean cuts with increasing weight among the HSL, XBD and LAC pigs implied a genotype × weight interaction that could best by explained by an apparent increase in the dominance of the halothane gene with increasing carcass weight. Key words: Swine, carcass composition, halothane gene, weight, Lacombe, Yorkshire


1989 ◽  
Vol 49 (3) ◽  
pp. 443-450 ◽  
Author(s):  
M. Wan Zahari ◽  
J. K. Thompson ◽  
D. Scott ◽  
J. H. Topps ◽  
W. Buchan ◽  
...  

ABSTRACTGroups of wether lambs were grown at different rates from about 24 kg live weight to 50 kg, by feeding them different amounts of the same concentrate diet. The slow growing lambs had higher contents of protein, ash, calcium (Ca), and phosphorus (P), and less fat and magnesium (Mg) than other groups. Differences in composition were significant between slow (120 g/day) and fast growth (230 g/day; P < 0-05) but not always between intermediate (160 g/day) and other growth rates. The differences became small and insignificant when data were expressed on a fat-free basis except for Mg which decreased with slow growth. Ash, for example, increased from 47 g/kg fat-free gain with fast growing animals to 54 g/kg with slow growth. Mg decreased from 0·44 g/kg fat-free gain with fast growth to 0·24 g/kg with slow growth. The data support the view that the ratio of ash to fat-free empty-body increases only slightly with age.The basic diet contained 3·9 g Ca per kg dry matter and the effect of a substantial supplement of calcium carbonate on lambs growing at the fast rate was to increase their retentions of ash, Ca and P by a factor greater than 1·25. There are alternative explanations for this finding. One possibility is that the availability of Ca in the basic diet had been reduced by unknown factors. It is also possible that the supplementary carbonate altered the acid/base status of the animals and resulted in conditions which favoured skeletal mineralization.


2016 ◽  
Vol 14 (3) ◽  
pp. e0604 ◽  
Author(s):  
Guillermo Ripoll ◽  
Pere Albertí ◽  
Javier Alvarez-Rodríguez ◽  
Isabel Blasco ◽  
Albina Sanz

The aim of this study was to analyse three commercial beef categories of the ‘Serrana de Teruel breed’ to define the appropriate commercial option. Twenty ‘Serrana de Teruel’ male calves at 9 months were assigned to the commercial beef categories (young bulls, bulls and steers), slaughtered at 12, 22 and 22 months of age, respectively. The in vivo ultrasound backfat thickness was greater than the dorsal fat thickness, and the young bulls and steers had a similar fat thickness, that was greater than the bulls in both areas. The slaughter weight and cold carcass weight were significantly different between the commercial categories. However, the differences were not sufficient to modify the dressing percentage, carcass conformation and fatness degree between the young bulls and bulls. The maximum stress of the muscle at 7 d of ageing was lower in the steers than in the young bulls and bulls. In general, the lightness of the meat in the bulls was lower than that in the young bulls and steers. The subcutaneous fat of the bull carcasses had a vivid colour and stored more carotenoids than that of the young bulls and steers. Hence, bulls produced heavier and better conformed carcasses with more edible meat and less fat than the other categories. However, steers are recommended to produce large carcasses with more trim and cover fat than the other categories. Finally, it seems that bulls are the most suitable commercial category to ‘Serrana de Teruel’ breed.


1988 ◽  
Vol 66 (8) ◽  
pp. 1532-1538 ◽  
Author(s):  
Lucie Maillette ◽  
Luc Bélisle ◽  
Maurice K. Seguin

Plant species of wind-exposed tundra sites are usually low lying and slow growing. Such a combination probably reduces competitive ability, perhaps to the point of limiting wind-tolerant species to sites with little or no competition, i.e., the most exposed sites, as if there were a trade-off between adaptation to physical conditions and competitive ability. That hypothesis was tested with Salix uva-ursi Pursh, an arctic–alpine species common on windy sites in northern Quebec. Salix uva-ursi increases in abundance with exposure to wind, contrary to other species, but tolerates, even "prefers", the physical conditions found in sheltered sites. These two observations support the idea that interspecific competition limits the distribution of S. uva-ursi. However, the vigour of S. uva-ursi (number and size of shoots) is greatest in the sheltered sites, where the other species are more numerous and vigourous. This apparent contradiction between distribution and vigour could find an explanation in the temporal variations in climate. Under favourable conditions, prostrate and slow growth would be a handicap to S. uva-ursi, compared with other species, whereas under harsh conditions, species sensitive to wind and cold would suffer more than S. uva-ursi. [Translated by the journal]


1988 ◽  
Vol 28 (2) ◽  
pp. 167 ◽  
Author(s):  
DO Kleemann ◽  
RW Ponzoni ◽  
JE Stafford ◽  
RJ Grimson

South Australian medium-wool (M), non- Peppin medium-wool Booroola (B) and Peppin medium-wool Trangie Fertility (TF) Merino rams were joined to M ewes at Turretfield Research Centre, South Australia, in 2 years. Carcass composition was assessed in the ewe and wether progeny at 2 mean slaughter liveweights, viz. 24 and 38 kg. When adjusted to the same carcass weight, B x M had 13% more carcass chemical fat, 15% more subcutaneous fat, 6% less bone and the same lean tissue as M. The same result was observed for TF x M in relation to M in year 2. However, TF x M had more lean and the same amount of subcutaneous and chemical fat as M in year 1. Within the Booroola strain, there were no differences between offspring from 3 sires with genotype FF and the 1 sire with + + for any of 5 variables analysed. We conclude that crossing the Booroola with the South Australian Merino produces carcasses with the same amount of lean tissue, less bone and more fat when compared at the same carcass weight. The rank of TF x M with the other strains for the major carcass components remains obscure owing to a strain x year interaction.


2009 ◽  
Vol 49 (6) ◽  
pp. 493 ◽  
Author(s):  
J. F. Graham ◽  
J. Byron ◽  
A. J. Clark ◽  
G. Kearney ◽  
B. Orchard

The present study is a component of a multi-site experiment, using Bos taurus cattle generated at four locations across southern Australia, designed to examine postweaning growth pathways for progeny whose sires were extreme in retail beef yield and intramuscular fat. Treatment and interaction effects on beef production and meat quality were examined within and across sites. The present paper describes the effect of postweaning growth and sire carcass type on liveweight and carcass traits at the Hamilton site. Angus sires selected on estimated breeding values for extremes in retail beef yield (RBY%), intramuscular fat (IMF%) (estimated breeding values for IMF% are derived by using live-animal ultrasound scanning) or both and sire breed types considered to be more extreme in those traits (Limousin, and Belgian Blue for yield, and Wagyu for intramuscular fat) were joined to crossbred and straight-bred cows. After weaning, the resultant 645 steer and heifer progeny were grown on a fast and slow growth path to ~550 kg and slaughtered, averaging 0.68 kg/day and 22.2 months, and 0.49 kg/day and 27.8 months for growth rate and age at slaughter, respectively. Growth path, sire carcass type and sex affected carcass traits; however, there were no sire carcass type by growth treatment interactions. The fast growth-path cattle were fatter, had more intramuscular fat (measured chemically), a higher Meat Standards of Australia (MSA) USA and AUS marble score, and a higher predicted MSA eating-quality score. Progeny of Wagyu sires were lighter at weaning and slaughter and had a lower hot standard carcass weight than the other sire carcass types. The Belgian Blue and Limousin progeny had a higher dressing percentage, a higher RBY% and a lower P8 and rib-fat depth and lower IMF% than the other sire breed types. Progeny of the high RBY% Angus had a lower rib-fat depth, a lower IMF% and higher RBY% than those selected for high IMF%. There was no difference in IMF% between the Wagyu or the high IMF% Angus. Progeny from the Belgian Blue, Limousin and Wagyu had a larger eye muscle area than the other sire breeds. The results indicate that simultaneous selection for supposedly antagonistic traits of IMF% and RBY% would result in carcass having high values of both measurements. Females were lighter than steers at slaughter, had a lower hot standard carcass weight, were fatter at the P8 and rib, and had a higher marble score and IMF%, a lower yield and a lower MSA-predicted eating-quality score than did steers. There was no interaction between postweaning growth and sire carcass type. These results indicate that with the use of appropriate sire carcass types and BREEDPLAN, and post-weaning nutrition, beef producers can confidently change carcass parameters to suit market specifications.


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