Prediction of carcass composition in meat breeds of sheep using computer tomography

1999 ◽  
Vol 1999 ◽  
pp. 43-43 ◽  
Author(s):  
M.J. Young ◽  
R.M. Lewis ◽  
K.A. McLean ◽  
N.A.A. Robson ◽  
J. Fraser ◽  
...  

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).

2006 ◽  
Vol 82 (3) ◽  
pp. 289-300 ◽  
Author(s):  
J. M. Macfarlane ◽  
R. M. Lewis ◽  
G. C. Emmans ◽  
M. J. Young ◽  
G. Simm

AbstractThe best means to utilize X-ray computed tomography (CT) and ultrasound to predict carcass lean, fat and bone weights in vivo in terminal sire sheep were tested. Data on 160 lambs from three breeds were considered: 50 Suffolk males, 50 Suffolk females, 40 Texel males and 20 Charollais males. One-fifth of the lambs within each breed and sex group were slaughtered at each of 14, 18 and 22 weeks of age and the remaining two-fifths at 26 weeks. Carcasses were dissected into lean, fat and bone weights. Prior to slaughter all lambs were CT scanned, with cross-sectional scans taken at seven sites along the body (ischium, hip, mid shaft of femur, 2nd and 5th lumbar vertebrae and 6th and 8th thoracic vertebrae), and ultrasound scanned at the 3rd lumbar vertebra and 13th rib.A set of three CT scans that reliably predicted carcass lean, fat and bone weights was identified which included a scan in each of the three main carcass regions: ischium in the hind leg, 5th lumbar vertebra in the loin and 8th thoracic vertebra in the shoulder. Breed and sex affected the intercepts of the prediction equations but not their slopes. Therefore, a minimal set of equations is likely to be sufficient to predict tissue weights, at least within terminal sire sheep breeds. Equations derived showed high degrees of fit to the data with R2values of 0·924, 0·978 and 0·830 for lean, fat and bone weights, respectively, when predicted using CT alone, and 0·589 and 0·857 for lean and fat weights, respectively, when predicted using ultrasound alone. Using live weight in addition to CT information only improved prediction accuracy slightly for lean (0·966) and fat (0·986) although more substantially for bone (0·925). Where live and tissue weights are considered contemporaneously in genetic evaluations, excluding live weight from prediction may therefore be preferable to avoid colinearity among weight measures.


animal ◽  
2007 ◽  
Vol 1 (1) ◽  
pp. 3-11 ◽  
Author(s):  
E. Karamichou ◽  
B.G. Merrell ◽  
W.A. Murray ◽  
G. Simm ◽  
S.C. Bishop

Author(s):  
J.M. Titchmarsh

The advances in recent years in the microanalytical capabilities of conventional TEM's fitted with probe forming lenses allow much more detailed investigations to be made of the microstructures of complex alloys, such as ferritic steels, than have been possible previously. In particular, the identification of individual precipitate particles with dimensions of a few tens of nanometers in alloys containing high densities of several chemically and crystallographically different precipitate types is feasible. The aim of the investigation described in this paper was to establish a method which allowed individual particle identification to be made in a few seconds so that large numbers of particles could be examined in a few hours.A Philips EM400 microscope, fitted with the scanning transmission (STEM) objective lens pole-pieces and an EDAX energy dispersive X-ray analyser, was used at 120 kV with a thermal W hairpin filament. The precipitates examined were extracted using a standard C replica technique from specimens of a 2¼Cr-lMo ferritic steel in a quenched and tempered condition.


Author(s):  
Imre Pozsgai ◽  
Klara Erdöhalmi-Torok

The paintings by the great Hungarian master Mihaly Munkacsy (1844-1900) made in an 8-9 years period of his activity are deteriorating. The most conspicuous sign of the deterioration is an intensive darkening. We have made an attempt by electron beam microanalysis to clarify the causes of the darkening. The importance of a study like this is increased by the fact that a similar darkening can be observed on the paintings by Munkacsy’s contemporaries e.g Courbet and Makart. A thick brown mass the so called bitumen used by Munkacsy for grounding and also as a paint is believed by the art historians to cause the darkening.For this study, paint specimens were taken from the following paintings: “Studio”, “Farewell” and the “Portrait of the Master’s Wife”, all of them are the property of the Hungarian National Gallery. The paint samples were embedded in a polyester resin “Poly-Pol PS-230” and after grinding and polishing their cross section was used for x-ray mapping.


Author(s):  
Judith M. Brock ◽  
Max T. Otten

A knowledge of the distribution of chemical elements in a specimen is often highly useful. In materials science specimens features such as grain boundaries and precipitates generally force a certain order on mental distribution, so that a single profile away from the boundary or precipitate gives a full description of all relevant data. No such simplicity can be assumed in life science specimens, where elements can occur various combinations and in different concentrations in tissue. In the latter case a two-dimensional elemental-distribution image is required to describe the material adequately. X-ray mapping provides such of the distribution of elements.The big disadvantage of x-ray mapping hitherto has been one requirement: the transmission electron microscope must have the scanning function. In cases where the STEM functionality – to record scanning images using a variety of STEM detectors – is not used, but only x-ray mapping is intended, a significant investment must still be made in the scanning system: electronics that drive the beam, detectors for generating the scanning images, and monitors for displaying and recording the images.


2007 ◽  
Vol 8 (2) ◽  
pp. 139-164 ◽  
Author(s):  
Manfred N Partl ◽  
Alexander Flisch ◽  
M Jönsson
Keyword(s):  

2021 ◽  
Vol 11 (7) ◽  
pp. 2971
Author(s):  
Siwei Tao ◽  
Congxiao He ◽  
Xiang Hao ◽  
Cuifang Kuang ◽  
Xu Liu

Numerous advances have been made in X-ray technology in recent years. X-ray imaging plays an important role in the nondestructive exploration of the internal structures of objects. However, the contrast of X-ray absorption images remains low, especially for materials with low atomic numbers, such as biological samples. X-ray phase-contrast images have an intrinsically higher contrast than absorption images. In this review, the principles, milestones, and recent progress of X-ray phase-contrast imaging methods are demonstrated. In addition, prospective applications are presented.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1271
Author(s):  
Andreas Koenig ◽  
Leonie Schmohl ◽  
Johannes Scheffler ◽  
Florian Fuchs ◽  
Michaela Schulz-Siegmund ◽  
...  

The aim of the study was to investigate the effect of X-rays used in micro X-ray computer tomography (µXCT) on the mechanical performance and microstructure of a variety of dental materials. Standardised bending beams (2 × 2 × 25 mm3) were forwarded to irradiation with an industrial tomograph. Using three-dimensional datasets, the porosity of the materials was quantified and flexural strength was investigated prior to and after irradiation. The thermal properties of irradiated and unirradiated materials were analysed and compared by means of differential scanning calorimetry (DSC). Single µXCT measurements led to a significant decrease in flexural strength of polycarbonate with acrylnitril-butadien-styrol (PC-ABS). No significant influence in flexural strength was identified for resin-based composites (RBCs), poly(methyl methacrylate) (PMMA), and zinc phosphate cement (HAR) after a single irradiation by measurement. However, DSC results suggest that changes in the microstructure of PMMA are possible with increasing radiation doses (multiple measurements, longer measurements, higher output power from the X-ray tube). In summary, it must be assumed that X-ray radiation during µXCT measurement at high doses can lead to changes in the structure and properties of certain polymers.


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