Computer tomographic investigation of subcutaneous adipose tissue as an indicator of body composition

<p>Abstract</p> <p>Background</p> <p>Modern computer tomography (CT) equipment can be used to acquire whole-body data from large animals such as pigs in minutes or less. In some circumstances, computer assisted analysis of the resulting image data can identify and measure anatomical features. The thickness of subcutaneous adipose tissue at a specific site measured by ultrasound, is used in the pig industry to assess adiposity and inform management decisions that have an impact on reproduction, food conversion performance and sow longevity. The measurement site, called "P2", is used throughout the industry. We propose that CT can be used to measure subcutaneous adipose tissue thickness and identify novel measurement sites that can be used as predictors of general adiposity.</p> <p>Methods</p> <p>Growing pigs (<it>N </it>= 12), were each CT scanned on three occasions. From these data the total volume of adipose tissue was determined and expressed as a proportion of total volume (fat-index). A computer algorithm was used to determined 10,201 subcutaneous adipose thickness measurements in each pig for each scan. From these data, sites were selected where correlation with fat-index was optimal.</p> <p>Results</p> <p>Image analysis correctly identified the limits of the relevant tissues and automated measurements were successfully generated. Two sites on the animal were identified where there was optimal correlation with fat-index. The first of these was located 4 intercostal spaces cranial to the caudal extremity of the last rib, the other, a further 5 intercostal spaces cranially.</p> <p>Conclusion</p> <p>The approach to image analysis reported permits the creation of various maps showing adipose thickness or correlation of thickness with other variables by location on the surface of the pig. The method identified novel adipose thickness measurement positions that are superior (as predictors of adiposity) to the site which is in current use. A similar approach could be used in other situations to quantify potential links between subcutaneous adiposity and disease or production traits.</p

Non-invasive study of changes in body composition in rabbits during pregnancy using X-ray computerized tomography

The objectives of this study were: 1 ) to follow changes in body composition during pregnancy using a non-invasive method; 2) to compare the results obtained with X-ray computerized tomography (CT) and with the slaughter method; and 3) to study the influence of litter size on changes in body reserves in pregnant does. Seventeen pregnant Pannon White rabbit does were examined by means of CT on the day of insemination, on days 14, 21 and 28 of pregnancy, and a few hours after parturition. At comparable time points, non-pregnant does (n = 26) were also scanned as a control group. During the CT procedure 27 images (scans) were taken from all of the animals in the body region from the scapular arch to the femoral-tibial articulation. The scans were processed by means of the computerized imaging technique, to obtain three-dimensional (3D) histograms that represented the changes in the water content, and in the fat and muscle tissues of the does. On the day after parturition all the does were slaughtered and the fat content of their empty bodies was subjected to chemical analysis. In the first 14 days of pregnancy little change was detected in body composition. Thereafter, in the abdominal region a marked increase was noted in densities corresponding to water and water-rich tissues, in correspondence with the growth of uterine contents. From day 21 of pregnancy a decrease in fat was noted in the pregnant does and an increase in the same reserves in the non-pregnant control group. To compare the fat content of animals in different physiological states so-termed fat indices were created by relating pixels corresponding to fat densities to the total number of pixels. In the same way muscle indices were created to demonstrate the changes in the muscle reserves during the experimental period. To test the accuracy of estimation by fat indices a regression analysis was carried out between the index numbers and the fat content subjected to chemical analysis. The result of this analysis showed a high correlation between the parameters examined. The same fat indices demonstrated a higher mobilisation of body reserves in does with higher litter size than in those with smaller litters

Changes of the fatty acid composition and malondialdehyde concentration in rabbit Longissimus dorsi muscle after regular electrical stimulation

The experiment was carried out to investigate, whether in vivo transcutaneous electrical nerve stimulation (TENS) affects the fatty acid composition and antioxidant status of rabbit Longissimus dorsi muscle. Altogether 20 Pannon White meat type rabbits were divided into two groups, from which one was routinely exposed to TENS treatment with the following settings: 2 events (each 20 min) a day/50 days, 1 channel (2 electrodes)/animal, 30 Hz, 20 mus impulse length and 10 mA. The control group was not treated. After slaughtering gas chromatography analysis of the Muscle showed significantly decreased stearic, arachidonic and docosahexaenoic acid proportions, while the estimated activity of the elongase enzyme decreased. The malondialdehyde concentration decreased insignificantly in the treated group, however, it followed the changes of the total highly unsaturated fatty acid amount (three or more double bonds), which decreased from 9.16% to 7.81%. The adaptation to the in vivo electrical treatment may significantly influence the meat fatty acid profile, especially PUFA proportion

THE EFFECT OF LIVE WEIGHT ON THE CARCASS TRAITS AND THE CHEMICAL COMPOSITION OF MEAT OF PANNON WHITE RABBITS BETWEEN 2.2 AND 3.5 KGS

[EN] For 267 Pannon White growing rabbits of both sexes slaughtered at a body weight of 2.2-2.4, 2.4-2.6, 2.6-2.8, 2.8-3.0, 3.0- 3.2, 3.2-3.4 and 3.4-3.5 kg, the average dressing percentage was 59.5, 60.7, 61.9, 62.2, 61.4, 62.4 and 62.1 % respectively. While the weight of live animals increased by about 50 % between 2.29 and 3.42 kg the change in the weight of blood (23 %), full gastrointestinal tract (26 %) and head (35 %) were the lowest, whereas the intermediate part (65 %), liver (82 %), skin (73 %), meat on hind legs (74 %), meat on the intermediate part (85 %) and perirenal fat (326 %) gained weight the most rapidly. 129 Pannon White rabbits were slaughtered between 2.2 and 3.5 kg live weight. The water, protein, fat and ash content of their meat was analyzed in the M. longissimus dorsi (LD), hind leg (HL) and M. /ongíssimus dorsi + belly (LD + B). Water content averaged 74.8, 73.8 and 71.0 % in LO, HL and LD + B respectively, whereas protein, fat and ash content averaged 23.1, 22.1 and 21.7 %, 1.08, 3.24 and 6.39 %, 1.15, 1.09 and 1.04 % respectively, in the arder of the meat parts Usted above. Water content decreased and fat content increased with increasing weight (r = -0.47, -0.33 and -0.51, r = 0.38, 0.31 and 0.45 for water and fat contents of LD, HL and LD + B respectively). Protein and ash content did not change significantly with weight.[FR] Pour 267 /apins en croissance de génotype Pannon White, des deux sexes, abattus au poids vif de 2,2-2,4; 2,4-2,6; 2,6-2,8; 2,8-3,0; 3,0- 3,2 ; 3,2-3,4 ; 3,4-3,5 kg, le rendement moyen a /'abattage a été de 59,5 - 60, 7 - 61,9 - 62,2 - 61,4 - 62,4 et 62, 1% respectivement. A/ors que le poids vif des animaux augmente d'environ 50% entre 2,29 et 3,42 kg, les augmentations de poids du sang (23%), du tractus gastrointestinal plein (26%), et de la téte (35%) ont été inférieures a cene du poids vif. A /'inverse, les augmentations de poids du rSble (65%), du foie (72%), de la peau (73%), des muse/es des pattes arriares ou du rSble (7 4% et 85%) et surtout du gras périrénal (326%) ont été plus rapides que ce/le du poids vif. Par ailleurs, 129 lapins Pannon White ont été abattus entre 2,2 et 3,5 kg de poids vif. Les teneurs en eau, protéines, lipides et matiares minéra/es ont été déterminées pour le muse/e longissimus dorsi (LO), /es muse/es d'une patte arriare (HL) et /'ensemble muscu/aire longissimus dorsi + paroi abdominale (LO + B). La teneur moyenne en eau est de 74,8- 73,8 et 71,0% pour LO, HL et LO+ B, tandis que les teneurs moyennes en protéines, lipides et minéraux des mémes ensemb/es muscu/aires sont de 23, 1 - 22, 1 et 21, 7 % ; 1,08 - 3,24 et 6,39% ; 1, 15 - 1,09 et 1,04 respectivement. Quand le poids vif augmente, la teneur en eau diminue et la teneur en lipides augmente (r = -0,47, -0,33 et -0,51 ; r = +0,38 ; +0,31 et +0,45 pour /'eau et les lipides de LO, HL et LO + B, respectivement). Les teneurs en protéines et en matiares minérales ne varient pes significativement avec le poíds vif.Szendrö, Z.; Randai, I.; Biro-Nemeth, E.; Romvari, R.; Milisits, G.; Kenessey, A. (1998). THE EFFECT OF LIVE WEIGHT ON THE CARCASS TRAITS AND THE CHEMICAL COMPOSITION OF MEAT OF PANNON WHITE RABBITS BETWEEN 2.2 AND 3.5 KGS. World Rabbit Science. 06(2). doi:10.4995/wrs.1998.351SWORD06

IN VIVO MEASUREMENT OF BODY PARTS AND FAT DEPOSITION IN RABBITS BY MRI

[EN] An experiment using Magnetic Resonance lmaging (MRI) tomography were done inwlving 87 rabbits el four genotypes, 12 or 16 weeks old. MRI was applied on the day before slaughter. The slices were taken in three orthogonal planes. The resufting pictures indicate that MRI provides very detailed slices. The volume of the fat deposit around the kldneys, the tml body fat volume of the body and the muscle el the hind part was collected from the MRI pictures. Correlation coefficients were computad between the volume of the perirenal fat ancl its weight, the muscle volume el the hind part ancl its weight, the tctal body fat volume and the crude fat content. The correlation values were found to be very high (O. n to 0.94) in the group of age 16 proving that the MRI tomograph is a excellent In vivo method to determine the volumes of fat and muscle. The la.ver correlation values in the group el age 12 (0.39 to 0.76) indicate that the MRI tomography is sensitiva to the digital sampling errors.[FR] Un total de 87 laplns appartensnt lt 4 génotypes ~s de 12 lt 16 semalnes ont été étudlés par lmsgerie en résonance magnétique (IRM). Les laplns ont été ana/ysés par IRM Is vei//e de fsbattage. Les "coupes• ont été réalisées dans 3 p/Bns orthogonaux. Les images obtenues pour chaque coupe sont tres détaillées. Le volume de la masse adipeuse p(riénBle, de fensemble des masses adipeuses du COITJS et ce/ui des masses musculaires de farrilJre de fanimal ont été détermlnées par analyse de coupes. Les coefficients de corrélation entre ces volumes détermlnés par IRM et /eur poids mesuré par dissection aprés abattage sont de O, 77 lt 0,94 chez les laplns de 16 semalnes. Ceci atieste que f/RM est une bonne méthode pour la mesure in vivo des volumes de tissu adipeux ou musculaire. Les vBleurs beaucoup plus faibles des corrélations obtenues chez les laplns de 12 semalnes, (0,39 it O, 76) montrent la limite de f/RM pour ce type d'étude (faible masse des tissus adipeux) en raison de se sensibilité aux erreurs d'analyse des images infonnatiques numérlséesThis work was supported by the E.C. (Copernicus) as a part of project CIPA-CT93-0206. The authors gratefully ackowledge E. Biro-Németh, L. Radnai and the staff of the CT Biological Centre of the Pannon Agricultural University for their expert assistanceKöver, G.; Szendrö, Z.; Romvari, R.; Jensen, J.; Sørensen, P.; Milisits, G. (1998). IN VIVO MEASUREMENT OF BODY PARTS AND FAT DEPOSITION IN RABBITS BY MRI. World Rabbit Science. 06(2). doi:10.4995/wrs.1998.349SWORD06