Accuracy of dual energy X-ray absorptiometry, weight, longissimus lumborum muscle depth and GR fat depth to predict half carcass composition in sheep

2007 ◽  
Vol 47 (10) ◽  
pp. 1165 ◽  
Author(s):  
F. R. Dunshea ◽  
D. Suster ◽  
P. J. Eason ◽  
R. D. Warner ◽  
D. L. Hopkins ◽  
...  
Keyword(s):  
Mineral Content ◽  
Dual Energy ◽  
Carcass Composition ◽  
Regression Equations ◽  
Tissue Mass ◽  
X Ray ◽  
Longissimus Lumborum ◽  
The Relationship ◽  
Non Destructive ◽  
Total Tissue

A Hologic QDR4500W dual energy X-ray absorptiometer (DXA) was used to measure body composition in 60 sheep half carcasses ranging from 8 to 28 kg. Half carcasses were from ewes and wethers of mixed genetics. Values determined by DXA, including total tissue mass (TTM), lean tissue mass (LTM), fat tissue mass (FTM) and bone mineral content (BMC), for the half carcass were evaluated by comparison with chemically determined composition. In the case of BMC, the relationship was with chemically determined ash content. Liveweight and chemically determined lean, fat and ash were strongly related to DXA-derived values for TTM, LTM, FTM and BMC, respectively (R2 = 0.999, 0.986, 0.989 and 0.920, respectively). However, because DXA estimates were different from chemically determined values in this sample of carcasses, they needed to be adjusted with the use of appropriate regression equations to correct the in-built algorithms. These data demonstrate the efficacy of DXA as a non-destructive method for determining the composition of the sheep half carcass.

The accuracy of dual energy X-ray absorptiometry (DXA), weight, and P2 back fat to predict half-carcass and primal-cut composition in pigs within and across research experiments

2004 ◽  
Vol 55 (9) ◽  
pp. 973 ◽  
Author(s):  
D. Suster ◽  
B. J. Leury ◽  
C. D. Hofmeyr ◽  
D. N. D'Souza ◽  
F. R. Dunshea
Keyword(s):  
Mineral Content ◽  
Dual Energy ◽  
Regression Equations ◽  
Lean Tissue ◽  
Large White ◽  
Tissue Mass ◽  
X Ray ◽  
Fat Composition ◽  
Non Destructive ◽  
Total Tissue

A Hologic QDR4500A dual energy X-ray absorptiometer (DXA) was used to measure body composition in 199 half-carcasses ranging from 15 to 48 kg. Half-carcasses were from animals of mixed sex and of either Large White × Landrace or Large White × Landrace × Duroc descent. Half-carcasses were selected from 5 different experiments to evaluate DXA accuracy within and across experiments. Values determined by DXA including total tissue mass, fat tissue mass, lean tissue mass, and bone mineral content, for the half-carcass and the shoulder, loin, belly, and ham primal cuts were evaluated by comparison with manually dissected composition. Relationships between manually dissected values and measurements of weight and backfat at the P2 site were also evaluated. Manually dissected values were strongly related to DXA-derived values, more so than with weight and P2 or a combination of both, particularly in the measurement of fat composition. In contrast to estimates derived from weight and P2, DXA-derived estimates remained accurate even when between-experiment variation was included. However, because DXA estimates were different from manually dissected values, they would need to be adjusted with the use of appropriate regression equations to correct the in-built algorithms. These results demonstrate the efficacy of DXA as a non-destructive method for determining the composition of the half-carcass and primal cuts, and its greater precision than current routinely used methods.

Repeatability of pig body composition measurements using dual energy X-ray absorptiometry and influence of animal size and subregional analyses

2006 ◽  
Vol 46 (11) ◽  
pp. 1447 ◽  
Author(s):  
D. Suster ◽  
B. J. Leury ◽  
D. J. Kerton ◽  
F. R. Dunshea
Keyword(s):  
Body Composition ◽  
Mineral Content ◽  
Regional Analysis ◽  
Dual Energy ◽  
Whole Body ◽  
Lean Tissue ◽  
Tissue Mass ◽  
X Ray ◽  
Animal Size ◽  
Total Tissue

Fifteen Large White × Landrace male pigs were used to investigate the influence of animal size and subregional analysis technique on dual energy X-ray absorptiometry body composition measurements and their repeatability. Pigs were scanned in triplicate with an Hologic QDR4500A X-ray absorptiometer at the beginning of the study (3 weeks of age, liveweight 5–10 kg) and then every 4 weeks until 19 weeks of age. Measurements made by dual energy X-ray absorptiometry included total tissue mass, lean tissue mass, fat tissue mass and bone mineral content. The QDR4500 software allows the scanned image to be divided into head, arms, legs and trunk using an in-built regional analysis grid that contains algorithms unique to each region. Different regional grid manipulations were performed at each scan to evaluate the effects of incorporating subregions into a whole body analysis over time. The dual energy X-ray absorptiometry measurements were highly repeatable and measurement repeatability improved as animal size increased. When results were averaged across regional grid placement and scan time, the most repeatable measurement was total tissue mass (CV = 0.21%), followed by lean tissue mass (CV = 0.59%), bone mineral content (CV = 2.50%) and fat tissue mass (CV = 2.71%). The placement of the regional analysis grid influenced the repeatability of all measurements except for total weight; however, this influence reduced with increasing animal size. It is recommended that the body of the scan image be positioned in the arm region and the head in the head region of the software regional analysis grid to measure whole body composition in pigs because it provides the most repeatable measure overall. Animal placement into the trunk region or utilising the full regional analysis option as specified by the manufacturer provided less repeatable results.

Genotype and age effects on sheep meat production. 4. Carcass composition predicted by dual energy X-ray absorptiometry

2007 ◽  
Vol 47 (10) ◽  
pp. 1172 ◽  
Author(s):  
E. N. Ponnampalam ◽  
D. L. Hopkins ◽  
F. R. Dunshea ◽  
D. W. Pethick ◽  
K. L. Butler ◽  
...  
Keyword(s):  
Bone Mineral ◽  
Mineral Content ◽  
Dual Energy ◽  
Carcass Composition ◽  
Age Effects ◽  
Meat Production ◽  
Semitendinosus Muscle ◽  
Eye Muscle ◽  
X Ray ◽  
Sheep Meat

This study compares the carcass composition of different genotypes of Australian sheep slaughtered at four ages (110, 236, 412 and 662 days of age, or 4, 8, 14 and 22 months of age). The genotypes used were Poll Dorsetgrowth × Border Leicester Merino (PDg × BLM), Poll Dorsetgrowth × Merino (PDg × M), Poll Dorsetmuscling × Merino (PDm × M), Merino × Merino (M × M) and Border Leicester × Merino (BL × M). Approximately 150 mixed sex animals were slaughtered at each age and the right sides (half carcass) were scanned by dual energy X-ray absorptiometry (DXA) for chemical lean, fat and bone mineral percentages of the carcass. Carcass lean percentage decreased (P < 0.001) across sire groups from Merino to Poll Dorset to Border Leicester at each age, while fatness increased (P < 0.001) in the opposite direction. With age, the magnitude of difference between genotypes for fatness became greater. There was a marked increase (P < 0.01) in ash mineral percentages in M × M and PDg × M genotypes relative to other genotypes in the 14- and 22-month groups. There were no differences (P > 0.1) between PDg × M and PDm × M in either chemical lean or fat percentages at any age but ash mineral percentage was higher in the PDg × M genotype at older ages (P < 0.05). This in turn led to differences in chemical lean : ash mineral content at later ages between PDg × M and PDm × M. Wethers had higher chemical lean (P < 0.05) and lower fat (P < 0.05) percentages in the carcass than ewes at all ages but ash mineral and chemical lean : ash mineral content did not differ between sexes. It was clear that the level of chemical lean or fat or ash mineral composition reached by some genotypes at one age was equivalent to that reached by other genotypes at the next measurement age. Those genotypes that reach a specification at younger ages will be more productive for meat production. Purebred Merino genetics will always be less productive in terms of carcass weight and muscle related productive traits (loin weight, semitendinosus muscle weight, eye muscle area) than BL and PD genetics, but the relative productivity of PD and BL genetics will depend on the traits used in the specification [see also Ponnampalam EN, Hopkins DL, Butler KL, Dunshea FR, Warner RD (2007) Genotype and age effects on sheep meat production. 2. Carcass quality traits. Australian Journal of Experimental Agriculure 47, 1147–1154]. The results suggest that selection for muscling had a greater impact on reducing ash mineral content associated with bone mineral mass than on increasing lean mass in the carcass.

scholarly journals Head, Neck, Trunk, and Pelvis Tissue Mass Predictions for Older Adults using Anthropometric Measures and Dual-Energy X-Ray Absorptiometry

2020 ◽  
Vol 8 (3) ◽  
pp. 14
Author(s):  
Charles A.J. Kahelin ◽  
Nicole C. George ◽  
Danielle L. Gyemi ◽  
David M. Andrews
Keyword(s):  
Older Adults ◽  
Dual Energy ◽  
Regression Equations ◽  
Prediction Equations ◽  
Tissue Mass ◽  
Younger Adults ◽  
X Ray ◽  
Recreational Activities ◽  
Biomechanical Models ◽  
Head Neck

Background: Regression equations using anthropometric measurements to predict soft (fat mass [FM], lean mass [LM], wobbling mass [WM]) and rigid (bone mineral content [BMC]) tissue masses of the extremities and core body segments have been developed for younger adults (16-35 years), but not older adults (36-65 years). Tissue mass estimates such as these would facilitate biomechanical modeling and analyses of older adults following fall or collision-related impacts that might occur during sport and recreational activities. Purpose: The purpose of this study was to expand on the previously established tissue mass prediction equations of the head, neck, trunk, and pelvis for healthy, younger adults by generating a comparable set of equations for an older adult population. Methods: A generation sample (38 males, 38 females) was used to create head, neck, trunk, and pelvis tissue mass prediction equations via multiple linear stepwise regression. A validation sample (13 males, 12 females) was used to assess equation accuracy; actual tissue masses were acquired from manually segmented full body Dual-Energy X-ray Absorptiometry scans. Results: Adjusted R2 values for the prediction equations ranged from 0.326 to 0.949, where BMC equations showed the lowest explained variances overall. Mean relative errors between actual and predicted masses ranged from –2.6% to 6.1% for trunk LM and FM, respectively. All actual tissue masses except head BMC (R2 = 0.092) were significantly correlated to those predicted from the equations (R2 = 0.403 to 0.963). Conclusion: This research provides a simple and effective method for predicting head, neck, trunk, and pelvis tissue masses in older adults that can be incorporated into biomechanical models for analyzing sport and recreational activities. Future work with this population should aim to improve core segment BMC predictions and develop equations for the extremities.

Head, Neck, Trunk, and Pelvis Tissue Mass Predictions for Young Adults Using Anthropometric Measures and Dual-Energy X-Ray Absorptiometry

2017 ◽  
Vol 33 (5) ◽  
pp. 366-372
Author(s):  
Danielle L. Gyemi ◽  
Charles Kahelin ◽  
Nicole C. George ◽  
David M. Andrews
Keyword(s):  
Young Adults ◽  
Head And Neck ◽  
Dual Energy ◽  
Regression Equations ◽  
Prediction Equations ◽  
Anthropometric Measures ◽  
Tissue Mass ◽  
X Ray ◽  
Head Neck

Accurate prediction of wobbling mass (WM), fat mass (FM), lean mass (LM), and bone mineral content (BMC) of living people using regression equations developed from anthropometric measures (lengths, circumferences, breadths, skinfolds) has previously been reported, but only for the extremities. Multiple linear stepwise regression was used to generate comparable equations for the head, neck, trunk, and pelvis of young adults (38 males, 38 females). Equations were validated using actual tissue masses from an independent sample of 13 males and 13 females by manually segmenting full-body dual-energy x-ray absorptiometry scans. Prediction equations exhibited adjusted R2 values ranging from .249 to .940, with more explained variance for LM and WM than BMC and FM, especially for the head and neck. Mean relative errors between predicted and actual tissue masses ranged from −11.07% (trunk FM) to 7.61% (neck FM). Actual and predicted tissue masses from all equations were significantly correlated (R2  = .329 to .937), except head BMC (R2  = .046). These results show promise for obtaining in-vivo head, neck, trunk, and pelvis tissue mass estimates in young adults. Further research is needed to improve head and neck FM and BMC predictions and develop tissue mass prediction equations for older populations.

Lumbar bone mineral content measured by dual energy X-ray absorptiometry in newborns and infants

1992 ◽  
Vol 81 (12) ◽  
pp. 953-958 ◽  
Author(s):  
Bernard L Salle ◽  
Pierre Braillon ◽  
Francis H Glorieux ◽  
Jacques Brunet ◽  
Eduardo Cavero ◽  
...  
Keyword(s):  
Bone Mineral Content ◽  
Bone Mineral ◽  
Mineral Content ◽  
Dual Energy ◽  
X Ray

scholarly journals Sodium loading, treadmill walking, and the acute redistribution of bone mineral content on dual energy X-ray absorptiometry scans

2019 ◽  
Vol 316 (1) ◽  
pp. R59-R67
Author(s):  
Tamara Hew-Butler ◽  
Kailyn Angelakos ◽  
Joshua Szczepanski
Keyword(s):  
Bone Mineral Content ◽  
Bone Mineral ◽  
Mineral Content ◽  
Dual Energy ◽  
Treadmill Walking ◽  
Primary Study ◽  
Intervention Trial ◽  
Dxa Scan ◽  
X Ray ◽  
Total Body

The purpose of this study was to assess relationships between plasma sodium concentration ([Na+]) and bone mineral content (BMC) after an acute sodium load plus treadmill walking and then quantify the amount of sodium the dual energy X-ray absorptiometry (DXA) scan could detect. The primary study was a single-blind randomized control crossover trial under two conditions: ingestion of six flour tablets (placebo trial) or six 1-g NaCl tablets (salt intervention trial). The tablets were ingested after baseline blood and urine collection followed immediately by the DXA scan. After 60 min of rest, a 45-min treadmill walk was conducted. Immediately postexercise, blood and urine were collected and the DXA scan was repeated. Main outcomes included changes (∆: post minus pre) in plasma [Na+] and BMC. Additionally, six 1-g NaCl tablets were superimposed over a DXA spine phantom for separate quantification of sodium as BMC. Fourteen subjects completed the primary study. Two-way repeated measures ANOVA tests revealed significant interaction ( F = 13.06; P = 0.0007), condition ( F = 21.88; P < 0.001), and time ( F = 6.51; P = 0.014) effects in plasma [Na+]. A significant condition ( F = 6.46; P = 0.014) effect was also noted in urine [Na+]. Total body BMC∆ was negatively correlated with plasma [Na+]∆ ( r = −0.43; P = 0.02) and urine [Na+]∆ ( r = −0.47; P = 0.01). Total body BMC∆ in the salt intervention trial [−5.5 (27) g] closely approximated the amount of NaCl ingested and subsequently absorbed into the bloodstream. The DXA scan quantified 67% of NaCl tablets as BMC in spine phantom analyses. Total body BMC∆ was negatively related to plasma and urine [Na+]∆ after treadmill walking. Reductions in total body BMC closely approximated the amount of NaCl ingested (~6 g). The DXA scan quantified NaCl as BMC.

scholarly journals Accuracy of predicting chemical body composition of growing pigs using dual-energy X-ray absorptiometry

2020 ◽  
Author(s):  
Claudia Kasper ◽  
Patrick Schlegel ◽  
Isabel Ruiz-Ascacibar ◽  
Peter Stoll ◽  
Giuseppe Bee
Keyword(s):  
Body Composition ◽  
Crude Protein ◽  
Imaging Techniques ◽  
Dual Energy ◽  
Growing Pigs ◽  
Regression Equations ◽  
Chemical Analyses ◽  
Prediction Equations ◽  
Animal Science ◽  
X Ray

AbstractStudies in animal science assessing nutrient and energy efficiency or determining nutrient requirements necessitate gathering exact measurements of body composition or body nutrient contents. Wet chemical analysis methods or standardized dissection are commonly applied, but both are destructive. Harnessing human medical imaging techniques for animal science can enable repeated measurements of individuals over time and reduce the number of individuals required for research. Among imaging techniques, dual-energy X-ray absorptiometry (DXA) is particularly promising. However, the measurements obtained with DXA do not perfectly match dissections or chemical analyses, requiring the adjustment of the DXA via calibration equations. Several calibration regressions have been published, but comparative studies are pending. Thus, it is currently not clear whether existing regression equations can be directly used to convert DXA measurements into chemical values or whether each individual DXA device will require its own calibration. Our study builds prediction equations that relate body composition to the content of single nutrients in growing entire male pigs (body weight range 20-100 kg) as determined by both DXA and chemical analyses, with R2 ranging between 0.89 for ash and 0.99 for water and crude protein. Moreover, we show that the chemical composition of the empty body can be satisfactorily determined by DXA scans of carcasses, with the prediction error rCV ranging between 4.3% for crude protein and 12.6% for ash. Finally, we compare existing prediction equations for pigs of a similar range of body weights with the equations derived from our DXA measurements and evaluate their fit with our chemical analyses data. We found that existing equations for absolute contents that were built using the same DXA beam technology predicted our data more precisely than equations based on different technologies and percentages of fat and lean mass. This indicates that the creation of generic regression equations that yield reliable estimates of body composition in pigs of different growth stages, sexes and genetic breeds could be achievable in the near future. DXA may be a promising tool for high-throughput phenotyping for genetic studies, because it efficiently measures body composition in a large number and wide array of animals.

scholarly journals Effect of calcitonin on renal osteodystrophy in hemodialysis patients. Measurement of bone mineral content by dual energy X-ray absorptiometry(DEXA).

1993 ◽  
Vol 26 (11) ◽  
pp. 1691-1696
Author(s):  
Yoshio Nomura ◽  
Hiroaki Mizoguchi ◽  
Masayuki Nakagawa ◽  
Nobuyoshi Nasu ◽  
Tsutomu Nishida ◽  
...  
Keyword(s):  
Bone Mineral Content ◽  
Bone Mineral ◽  
Renal Osteodystrophy ◽  
Mineral Content ◽  
Hemodialysis Patients ◽  
Dual Energy ◽  
X Ray
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