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G Simm - One of the best experts on this subject based on the ideXlab platform.
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prediction of lamb Carcass Composition and meat quality using combinations of post mortem measurements
Meat Science, 2009Co-Authors: N R Lambe, Ea Navajas, A. V. Fisher, L Bunger, R Roehe, G SimmAbstract:Various post-mortem measurements (Carcass weights, conformation and fatness classes, external Carcass dimensions, eye muscle dimensions, subcutaneous fat depth, pH and temperature) were recorded on 197 Texel (TEX) and 200 Scottish Blackface (SBF) lamb Carcasses. The potential use of these measurements to predict Carcass Composition and key meat quality traits was investigated, to enable categorisation of Carcasses in the abattoir and/or for use in genetic improvement programmes. By combining different measurements, accurate predictions of dissected Carcass muscle weight (adjusted R(2) 0.93 in TEX, 0.88 in SBF) and fat weight (adjusted R(2) 0.84 in TEX, 0.87 in SBF) were achieved, and moderate predictions of intra-muscular fat (adjusted R(2) 0.56 in TEX, 0.48 in SBF), whilst shear force was predicted with low to moderate accuracy (adjusted R(2)<0.33 across breeds and cuts). Sex, eye muscle dimensions and subcutaneous fat depth improved predictions of Carcass Composition and intra-muscular fat, whilst pH or temperature provided little additional benefit for these traits, but increased prediction accuracies for shear force. These results could contribute to the development of automated Carcass grading systems or help inform breeding decisions.
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The consequences of index selection on Carcass Composition in Suffolk sheep
Proceedings of the British Society of Animal Science, 1999Co-Authors: R. M. Lewis, G Simm, W S Dingwall, J Fitzsimons, G. C. Emmans, J.c. Fraser, J.e. DonbavandAbstract:Early in the 1980s a selection index was designed at SAC to improve the rate of lean growth in terminal sire sheep which combined ultrasound measurements of fat and muscle depth, and live weight at 150 days of age (Simm and Dingwall, 1989). Beginning in 1985, this index was applied in the SAC Suffolk flock in a performance test. In 1994, rams from a line selected on this index weighed on average 12% more (8 kg) and had 12% lower fat depth (– 0.9 mm) and 10% higher muscle depth (2.9 mm) than rams from an unselected Control line. Comparison of Selection and Control line animals has thus far been based on live predictors of Carcass Composition at weights substantially heavier than typical market lamb weights. The aims of this study were to test whether selection decisions based on the lean growth index produced an improvement in actual Carcass Composition in purebred terminal sire sheep and whether these changes persisted at live weights different from those under which selection was carried out.
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Prediction of Carcass Composition in meat breeds of sheep using computer tomography
Proceedings of the British Society of Animal Science, 1999Co-Authors: M.j. Young, J Fitzsimons, R. M. Lewis, K.a. Mclean, N.a.a. Robson, J. Fraser, J. Donbavand, G SimmAbstract:Ultrasound imaging has proved a very useful tool for the modern animal breeder wishing to improve Carcass Composition. However, more accurate imaging technologies, such as X-ray Computer Tomography (CT), could accelerate genetic improvement of Carcass Composition, and widen the range of traits assessed (e.g. by considering deeper tissues). Carcass quality is assuming more importance for breeders but quality traits are difficult to assess objectively and accurately in live sheep. The present study was designed to identify a few CT scan positions from which accurate prediction of dissected tissue weights could be made in meat sheep.One hundred Suffolk lambs (50 of each sex) were CT scanned and slaughtered at 14, 18, 22 or 26 weeks of age (59±16kg LW, range 20-96kg). Each animal was scanned at seven sites; three in the gigot (ISC, caudal ischium; FEM, mid-shaft of femur; HIP, hip joint), two in the loin (LV5 and LV2, 5th and 2nd lumbar vertebrae) and two in the chest/ shoulder (TV8 and TV6, 8th and 6th thoracic vertebrae).
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Genetic variation and relationship of ultrasonic measures and Carcass Composition in Suffolk cross lambs
Proceedings of the British Society of Animal Science, 1996Co-Authors: V.c. Flamarique, R. M. Lewis, G SimmAbstract:Excess fat in lamb is regarded as an important reason for less lamb meat being purchased by consumers. This has encouraged the development and use (particularly in Terminal Sire breeds) of selection indices that can identify animals that will sire leaner progeny. These indices usually include live weight and in vivo predictors of body Composition, such as an ultrasonic measurement of muscle and fat depth, as selection criteria (Simm and Dingwall, 1989). But the usefulness of such in vivo measurements as predictors of Carcass Composition depends on the correlation between, and the variation in, live and Carcass measures. The objectives of this study were to determine the strength of the relationship between ultrasound and dissection measures of Carcass Composition, and the degree of genetic variation in these measures, in crossbred progeny of Suffolk rams.
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Selection for improved Carcass Composition in Suffolk Sheep : Interim Results
Proceedings of the British Society of Animal Production (1972), 1990Co-Authors: G Simm, W S Dingwall, S V Murphy, J Fitzsimons, W R BrownAbstract:It is likely that returns from lamb production in future will depend, much more than at present, on producing leaner Carcasses. There are several short-term changes in management which could produce leaner Carcasses. However, In the longer term genetic Improvement, particularly by within-breed selection In terminal sire breeds, is likely to provide permanent, cumulative and cost-effective benefits In Carcass Composition. In the early 1980s a research project was started at the Edinburgh School of Agriculture, using Suffolk sheep, to examine the genetic potential for Improving Carcass Composition In terminal sires. The work commenced with an evaluation of techniques for in vivo measurement of Carcass Composition (Simm, 1987) and derivation of selection indices to incorporate In vivo measurements (Simm and Dingwall, 1989). Since 1985 In vivo measurement and Index selection have been practised In the experimental flock, which now numbers about 220 ewes. This paper reports the interim results of selection.
K Schellander - One of the best experts on this subject based on the ideXlab platform.
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epistatic qtl pairs associated with meat quality and Carcass Composition traits in a porcine duroc pietrain population
Genetics Selection Evolution, 2010Co-Authors: Christine Grosebrinkhaus, Elisabeth Jonas, Heiko Buschbell, C Phatsara, Dawit Tesfaye, Heinz Jungst, Christian Looft, K SchellanderAbstract:Background: Quantitative trait loci (QTL) analyses in pig have revealed numerous individual QTL affecting growth, Carcass Composition, reproduction and meat quality, indicating a complex genetic architecture. In general, statistical QTL models consider only additive and dominance effects and identification of epistatic effects in livestock is not yet widespread. The aim of this study was to identify and characterize epistatic effects between common and novel QTL regions for Carcass Composition and meat quality traits in pig. Methods: Five hundred and eighty five F2 pigs from a Duroc × Pietrain resource population were genotyped using 131 genetic markers (microsatellites and SNP) spread over the 18 pig autosomes. Phenotypic information for 26 Carcass Composition and meat quality traits was available for all F2 animals. Linkage analysis was performed in a two-step procedure using a maximum likelihood approach implemented in the QxPak program. Results: A number of interacting QTL was observed for different traits, leading to the identification of a variety of networks among chromosomal regions throughout the porcine genome. We distinguished 17 epistatic QTL pairs for Carcass Composition and 39 for meat quality traits. These interacting QTL pairs explained up to 8% of the phenotypic variance. Conclusions: Our findings demonstrate the significance of epistasis in pigs. We have revealed evidence for epistatic relationships between different chromosomal regions, confirmed known QTL loci and connected regions reported in other studies. Considering interactions between loci allowed us to identify several novel QTL and traitspecific relationships of loci within and across chromosomes.
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Epistatic QTL pairs associated with meat quality and Carcass Composition traits in a porcine Duroc × Pietrain population
Genetics Selection Evolution, 2010Co-Authors: Christine Große-brinkhaus, Elisabeth Jonas, Heiko Buschbell, C Phatsara, Dawit Tesfaye, Heinz Jungst, Christian Looft, K Schellander, Ernst TholenAbstract:Background: Quantitative trait loci (QTL) analyses in pig have revealed numerous individual QTL affecting growth, Carcass Composition, reproduction and meat quality, indicating a complex genetic architecture. In general, statistical QTL models consider only additive and dominance effects and identification of epistatic effects in livestock is not yet widespread. The aim of this study was to identify and characterize epistatic effects between common and novel QTL regions for Carcass Composition and meat quality traits in pig. Methods: Five hundred and eighty five F2 pigs from a Duroc × Pietrain resource population were genotyped using 131 genetic markers (microsatellites and SNP) spread over the 18 pig autosomes. Phenotypic information for 26 Carcass Composition and meat quality traits was available for all F2 animals. Linkage analysis was performed in a two-step procedure using a maximum likelihood approach implemented in the QxPak program. Results: A number of interacting QTL was observed for different traits, leading to the identification of a variety of networks among chromosomal regions throughout the porcine genome. We distinguished 17 epistatic QTL pairs for Carcass Composition and 39 for meat quality traits. These interacting QTL pairs explained up to 8% of the phenotypic variance. Conclusions: Our findings demonstrate the significance of epistasis in pigs. We have revealed evidence for epistatic relationships between different chromosomal regions, confirmed known QTL loci and connected regions reported in other studies. Considering interactions between loci allowed us to identify several novel QTL and traitspecific relationships of loci within and across chromosomes.
Elisabeth Jonas - One of the best experts on this subject based on the ideXlab platform.
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epistatic qtl pairs associated with meat quality and Carcass Composition traits in a porcine duroc pietrain population
Genetics Selection Evolution, 2010Co-Authors: Christine Grosebrinkhaus, Elisabeth Jonas, Heiko Buschbell, C Phatsara, Dawit Tesfaye, Heinz Jungst, Christian Looft, K SchellanderAbstract:Background: Quantitative trait loci (QTL) analyses in pig have revealed numerous individual QTL affecting growth, Carcass Composition, reproduction and meat quality, indicating a complex genetic architecture. In general, statistical QTL models consider only additive and dominance effects and identification of epistatic effects in livestock is not yet widespread. The aim of this study was to identify and characterize epistatic effects between common and novel QTL regions for Carcass Composition and meat quality traits in pig. Methods: Five hundred and eighty five F2 pigs from a Duroc × Pietrain resource population were genotyped using 131 genetic markers (microsatellites and SNP) spread over the 18 pig autosomes. Phenotypic information for 26 Carcass Composition and meat quality traits was available for all F2 animals. Linkage analysis was performed in a two-step procedure using a maximum likelihood approach implemented in the QxPak program. Results: A number of interacting QTL was observed for different traits, leading to the identification of a variety of networks among chromosomal regions throughout the porcine genome. We distinguished 17 epistatic QTL pairs for Carcass Composition and 39 for meat quality traits. These interacting QTL pairs explained up to 8% of the phenotypic variance. Conclusions: Our findings demonstrate the significance of epistasis in pigs. We have revealed evidence for epistatic relationships between different chromosomal regions, confirmed known QTL loci and connected regions reported in other studies. Considering interactions between loci allowed us to identify several novel QTL and traitspecific relationships of loci within and across chromosomes.
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Epistatic QTL pairs associated with meat quality and Carcass Composition traits in a porcine Duroc × Pietrain population
Genetics Selection Evolution, 2010Co-Authors: Christine Große-brinkhaus, Elisabeth Jonas, Heiko Buschbell, C Phatsara, Dawit Tesfaye, Heinz Jungst, Christian Looft, K Schellander, Ernst TholenAbstract:Background: Quantitative trait loci (QTL) analyses in pig have revealed numerous individual QTL affecting growth, Carcass Composition, reproduction and meat quality, indicating a complex genetic architecture. In general, statistical QTL models consider only additive and dominance effects and identification of epistatic effects in livestock is not yet widespread. The aim of this study was to identify and characterize epistatic effects between common and novel QTL regions for Carcass Composition and meat quality traits in pig. Methods: Five hundred and eighty five F2 pigs from a Duroc × Pietrain resource population were genotyped using 131 genetic markers (microsatellites and SNP) spread over the 18 pig autosomes. Phenotypic information for 26 Carcass Composition and meat quality traits was available for all F2 animals. Linkage analysis was performed in a two-step procedure using a maximum likelihood approach implemented in the QxPak program. Results: A number of interacting QTL was observed for different traits, leading to the identification of a variety of networks among chromosomal regions throughout the porcine genome. We distinguished 17 epistatic QTL pairs for Carcass Composition and 39 for meat quality traits. These interacting QTL pairs explained up to 8% of the phenotypic variance. Conclusions: Our findings demonstrate the significance of epistasis in pigs. We have revealed evidence for epistatic relationships between different chromosomal regions, confirmed known QTL loci and connected regions reported in other studies. Considering interactions between loci allowed us to identify several novel QTL and traitspecific relationships of loci within and across chromosomes.
C Phatsara - One of the best experts on this subject based on the ideXlab platform.
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epistatic qtl pairs associated with meat quality and Carcass Composition traits in a porcine duroc pietrain population
Genetics Selection Evolution, 2010Co-Authors: Christine Grosebrinkhaus, Elisabeth Jonas, Heiko Buschbell, C Phatsara, Dawit Tesfaye, Heinz Jungst, Christian Looft, K SchellanderAbstract:Background: Quantitative trait loci (QTL) analyses in pig have revealed numerous individual QTL affecting growth, Carcass Composition, reproduction and meat quality, indicating a complex genetic architecture. In general, statistical QTL models consider only additive and dominance effects and identification of epistatic effects in livestock is not yet widespread. The aim of this study was to identify and characterize epistatic effects between common and novel QTL regions for Carcass Composition and meat quality traits in pig. Methods: Five hundred and eighty five F2 pigs from a Duroc × Pietrain resource population were genotyped using 131 genetic markers (microsatellites and SNP) spread over the 18 pig autosomes. Phenotypic information for 26 Carcass Composition and meat quality traits was available for all F2 animals. Linkage analysis was performed in a two-step procedure using a maximum likelihood approach implemented in the QxPak program. Results: A number of interacting QTL was observed for different traits, leading to the identification of a variety of networks among chromosomal regions throughout the porcine genome. We distinguished 17 epistatic QTL pairs for Carcass Composition and 39 for meat quality traits. These interacting QTL pairs explained up to 8% of the phenotypic variance. Conclusions: Our findings demonstrate the significance of epistasis in pigs. We have revealed evidence for epistatic relationships between different chromosomal regions, confirmed known QTL loci and connected regions reported in other studies. Considering interactions between loci allowed us to identify several novel QTL and traitspecific relationships of loci within and across chromosomes.
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Epistatic QTL pairs associated with meat quality and Carcass Composition traits in a porcine Duroc × Pietrain population
Genetics Selection Evolution, 2010Co-Authors: Christine Große-brinkhaus, Elisabeth Jonas, Heiko Buschbell, C Phatsara, Dawit Tesfaye, Heinz Jungst, Christian Looft, K Schellander, Ernst TholenAbstract:Background: Quantitative trait loci (QTL) analyses in pig have revealed numerous individual QTL affecting growth, Carcass Composition, reproduction and meat quality, indicating a complex genetic architecture. In general, statistical QTL models consider only additive and dominance effects and identification of epistatic effects in livestock is not yet widespread. The aim of this study was to identify and characterize epistatic effects between common and novel QTL regions for Carcass Composition and meat quality traits in pig. Methods: Five hundred and eighty five F2 pigs from a Duroc × Pietrain resource population were genotyped using 131 genetic markers (microsatellites and SNP) spread over the 18 pig autosomes. Phenotypic information for 26 Carcass Composition and meat quality traits was available for all F2 animals. Linkage analysis was performed in a two-step procedure using a maximum likelihood approach implemented in the QxPak program. Results: A number of interacting QTL was observed for different traits, leading to the identification of a variety of networks among chromosomal regions throughout the porcine genome. We distinguished 17 epistatic QTL pairs for Carcass Composition and 39 for meat quality traits. These interacting QTL pairs explained up to 8% of the phenotypic variance. Conclusions: Our findings demonstrate the significance of epistasis in pigs. We have revealed evidence for epistatic relationships between different chromosomal regions, confirmed known QTL loci and connected regions reported in other studies. Considering interactions between loci allowed us to identify several novel QTL and traitspecific relationships of loci within and across chromosomes.
M E Einstein - One of the best experts on this subject based on the ideXlab platform.
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ractopamine treatment biases in the prediction of pork Carcass Composition
Journal of Animal Science, 2003Co-Authors: A P Schinckel, C T Herr, B T Richert, J C Forrest, M E EinsteinAbstract:Carcass and live measurements of 45 barrows were used to evaluate the magnitude of ractopamine (RAC) treatment prediction biases for measures of Carcass Composition. Barrows (body weight = 69.6 kg) were allotted by weight to three dietary treatments and fed to an average body weight of 114 kg. Treatments were: 1) 16% crude protein, 0.82% lysine control diet (CON); 2) control diet + 20 ppm RAC (RAC16); 3) a phase feeding sequence with 20 ppm RAC (RAC-P) consisting of 18% crude protein (1.08%. lysine) during wk 1 and 4, 20% crude protein (1.22% lysine) during wk 2 and 3, 16% crude protein (0.94% lysine) during wk 6, and 16% crude protein (0.82% lysine) during wk 6. The four lean cuts from the right side of the Carcasses (n = 15/treatment) were dissected into lean and fat tissue. The other cut soft tissue was collected from the jowl, ribs, and belly. Proximate analyses were completed on these three tissue pools and a sample of fat tissue from the other cut soft tissue. Prediction equations were developed for each of five measures of Carcass Composition: fat-free lean, lipid-free soft tissue, dissected lean in the four lean cuts, total Carcass fat tissue, and soft-tissue lipid mass. Ractopamine treatment biases were found for equations in which midline backfat, ribbed Carcass, and live ultrasonic measures were used as single technology sets of measurements. Prediction equations from live or Carcass measurements underpredicted the lean mass of the RAC-P pigs and underpredicted the lean mass of the CON pigs. Only 20 to 50% of the true difference in fat-free lean mass or lipid-free soft-tissue mass between the control pigs and pigs fed RAC was predicted from equations including standard Carcass measurements. The soft-tissue lipid and total Carcass fat mass of RAC-P pigs was overpredicted from the Carcass and live ultrasound measurements. Prediction equations including standard Carcass measurements with dissected ham lean alone or with dissected loin lean reduced the residual standard deviation and magnitude of biases for the three measures of Carcass lean mass. Prediction equations including the percentage of lipid of the other cut soft tissue improved residual standard deviation and reduced the magnitude of biases for total Carcass fat mass and soft-tissue lipid. Prediction equations for easily obtained Carcass or live ultrasound measures will only partially predict the true effect of RAC to increase Carcass leanness. Accurate prediction of the Carcass Composition of RAC-fed pigs requires some partial dissection, chemical analysis, or alternative technologies.
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evaluation of alternative measures of pork Carcass Composition
Journal of Animal Science, 2001Co-Authors: A P Schinckel, J C Forrest, J R Wagner, M E EinsteinAbstract:Carcass and live measurements of 203 pigs representing seven genetic populations and four target live weights (100, 114, 128, and 152 kg) were used to evaluate alternative measures of Carcass Composition. Measures of Carcass lean (fat tissue-free lean, FFLM; lipid-free soft tissue, LFSTIS; and dissected lean in the four lean cuts, DL), fat (total Carcass fat tissue, TOFAT), and lipid mass (soft tissue lipid, STLIP) were evaluated. Overall, LFSTIS was 22.8% greater than FFLM (47.8 vs 38.9 kg) and TOFAT was 30% greater than STLIP (38.5 vs 29.6 kg). The allometric growth coefficients relative to Carcass weight were different for the measures: b = 0.776, 0.828, 0.794, 1.37, and 1.49 for FFLM, LFSTIS, DL, TOFAT, and STLIP, respectively. At 90 kg Carcass weight, the predicted growth of FFLM, LFSTIS, TOFAT, and STLIP was 0.314, 0.420, 0.553, and 0.446 kg/kg increase in Carcass weight. The difference between FFLM and LFSTIS, representing nonlipid components of the Carcass fat tissue, was greater for barrows than for gilts (9.2 vs 8.6 kg). Lipid-free soft tissue mass was predicted more accurately from Carcass or live animal measurements than FFLM with smaller relative RSD (4.6 vs 6.5% of their mean values). The alternative measures of Carcass Composition were evaluated as predictors of empty body protein (MTPRO) and lipid (MTLIP) mass. Empty body protein was predicted with similar accuracy (R 2 = 0.74 to 0.81) from either DL, FFLM, LFSTIS, or ribbed Carcass measurements. Empty body lipid was predicted more accurately from TOFAT (R 2 = 0.92) or STLIP (R 2 = 0.93) than ribbed Carcass measurements (R 2 = 0.88). Although the alternative measures of lean mass (LFSTIS vs FFLM) and lipid mass (TOFAT vs STLIP) were highly related to each other (r = 0.93 to 0.98), they had different relative growth rates (allometric coefficients) and thus cannot be predicted as linear functions of the similar alternative variable without significant weight group biases. From the 100- to 152-kg target weight groups, gilts gained 12.9% greater FFLM and 12.1% greater MTPRO but only 4.4% greater LFSTIS than barrows. Fat-free lean mass is more precise as a measure of muscle growth and as a predictor of lysine requirements. Lipid-free soft tissue can be obtained more quickly and predicted more accurately from Carcass or live animal measurements.