Regional markets require a large variety of pig breeds and pork products. Noninvasive techniques like computed tomography, magnetic resonance imaging, dual-energy X-ray absorptiometry, computer vision, or, very often, ultrasound helps to provide the information required for breeding, quality control, payment, and processing. Meanwhile, computed tomography is being used as phenotyping tool by leading pig breeding organizations around the world, while ultrasound B- or A-mode techniques belong to the standard tools, especially to measure subcutaneous fat and muscle traits. Magnetic resonance imaging and dual-energy X-ray absorptiometry, however, are still mainly used as research tools to develop and characterize new phenotypic traits, which usually could not be measured without slaughtering the breeding pigs. A further noninvasive method—already used on a commercial basis, not only in abattoirs—is video 2D or 3D imaging. This chapter will review the latest developments for these noninvasive techniques.

A number of parameters have been used to assess the impact ofcoccidiosis on chickens in clinical settings as well as in experimental studies. However, a rapid way to determine body composition would be useful to evaluate or compare responses to coccidia and could give further insight into the metabolic impact of infection. The current study evaluates the use of dual X-ray absorptiometry (DEXA) to determine the impact of coccidiosis on body composition in chicks receiving inoculations with single or mixed species of Eimeria. Chicks infected with Eimeria maxima, Eimeria acervulina, or Eimeria tenella had altered parameters of body composition as measured by DEXA at 6 days postinfection (PI). The greatest effects were noted in birds infected with E. acervulina or E. maxima, where lean mass and fat were reduced from control values about 75% and 85%, respectively. In chicks infected with E. tenella, tissue and fat were reduced about 10%. Bone mineral content (BMC) was about 75% of control values in birds infected with E. acervulina or E. maxima, but only E. acervulina altered bone mineral density (BMD). The decreases in BMC and BMD are likely due to malabsorption. In chicks receiving a mixed coccidian infection, all DEXA parameters were significantly decreased at 8 days PI compared with age-matched controls. As with single infections, BMD and BMC were significantly depressed (P < 0.05). Values of all DEXA parameters were near 92% of control values by day 16 PI. Analysis of all birds in the current study indicates DEXA tissue weight slightly underestimated the gravimetrically measured weight by about 3%. The current results demonstrate that DEXA is a potentially important tool for the rapid evaluation of the effect of coccidiosis on broiler chicks and suggest it can be useful for evaluation of vaccines and other disease controls.

The growth and composition of the neonatal pig is of interest because of potential impact on subsequent growth and finally, composition at market weight. The purpose of this study was to compare at weaning the growth and body composition of the largest and smallest pigs from each of 38 litters. At weaning (27 +/- 1.7 d) the largest (9.3 +/- 1.1 kg) and smallest (6.2 +/- 1.5 kg) pigs were selected for body composition measurement by dual energy X-ray absorptiometry (DXA). The body composition of the largest pigs consisted of 38% more fat, 32% more lean, and 29% more bone mineral content (P<0.001). However, when expressed as a percentage of body weight, there was no difference in the fat, lean or bone mineral content content of the two groups of pigs (P>0.05). A second study consisted of 12 pairs of pigs from 8 litters that were selected on the basis of having the same birth weight, but one pig out gaining the other by at least 50 g/day. At 21 days of age the selected pigs were scanned by DXA. For both groups combined, the correlation (r) between body weight and lean mass was 0.99, between body weight and fat mass it was 0.87, and between body weight at birth and body weight at weaning it was 0.56. The results of these studies revealed that, at weaning, the fastest and slowest growing pigs had similar proportions of fat, lean and bone mineral and, consistent with previous results, the rates of both fat and lean deposition were highly correlated (P<0.001) with total body growth rate.

The purpose of this study was to use quantitative magnetic resonance (QMR) to measure changes in the body composition of piglets during growth from birth to 4 kg body weight. Using QMR, 60 pigs were scanned an average of 5 times starting at 2.7 +/- 1.3 days of age (1.95 kg) and finally at 13.1 +/- 4.3 days (4.14 kg). Regression analysis revealed that the rates of total body growth and fat and lean deposition were linear throughout this period. Subsequently, a second group of 235 pigs (109 males and 126 females) were scanned twice, first at 2.7 +/- 1.2 days of age and then at 13.4 +/- 3.1 days of age. The mean (+/- SD) rate of total body growth was 230 +/- 57 g/day. The rates of fat and lean deposition were 40 13 g/day and 191 +/- 52 g/day, respectively. The rates of both fat and lean deposition were highly correlated (P<0.001) with total body growth rate (R-2=0.81 and 0.93, respectively) and the coefficient of determination between the rates of fat and lean deposition was 0.71 (P<0.001). The results of this study demonstrate that QMR is a useful method for measuring changes in body composition in neonatal pigs. Furthermore, the results indicate that during the period of growth from birth to 4 kg, the rates of both fat and lean deposition are linear and highly correlated with total body growth.

Lipids play a vital role in the architecture of cell membranes. About one third of the known cellular proteins are located in the membrane lipid and these are largely the transporters, signalers, receptors and defense systems. The fatty acid component in membranes across species and in different cell types is species, organ and sub cellular specific. In human cell types, the inner cell membrane is dominated by arachidonic acid whilst that of the photo receptor and neural synapse is strikingly rich in docosahexaenoic acid. The biophysical basis for this molecular specificity in not understood.

Changes in energy intake affects metabolic function in adipose tissue that plays a central role in lipid and glucose metabolism and the production of hormones and inflammatory cytokines. To determine the effects of excess calories from fructose and/or fat on adipose tissue and liver gene expression, 32 conventional crossbred juvenile pigs were randomized and fed 1) a basal calorie diet alone or 2) with added fructose (20% of total calories); or 3) a high calorie diet with added fat alone or 4) with added fat and fructose for 12 wk. Total body fat deposition detected by DXA‐scan and carcass digestion, and gene expression in liver and visceral and peripheral adipose tissue was measured. The results indicated that both high fat diets induced a significant body weight gain and fat deposition with expression of inflammatory genes in liver and visceral adipose‐derived stromal cells. Pigs on the basal diet with added fructose showed a marginal gain in bodyweight with no difference in fat deposition or induction of inflammation when compared to pigs on the basal diet. However, the combination of added fructose and fat induced expression of lipogenic genes (fatty acid binding protein (FABP4), stearoyl‐CoA desaturase (SCD), and leptin in adipocytes isolated from peripheral fat. Thus, excess dietary fructose combined with a high fat diet can exacerbate fat deposition and body weight gain by promoting lipidogenesis.

Bone morphogenetic protein 11 (BMP11) is a key regulatory protein in skeletal development. BMP11 propeptide has been shown to antagonize GDF11 activity in vitro. To explore the role of BMP11 propeptide in skeletal formation in vivo, we generated transgenic mice with skeleton-specific overexpression of BMP11 propeptide cDNA. The mice showed a transformation of the seventh cervical vertebra into a thoracic vertebra in our previous report. Presently, further characterizations of the transgenic mice indicated that ossification in calvatia was dramatically enhanced in transgenic fetuses at 16.5 dpc in comparison with their wild-type littermates. At 10 weeks of age, bone mineral content and bone mineral density were significantly (P < 0.05) higher in transgenic mice than that in their wild-type littermates based on dual energy X-ray absorptiometry analysis. The relative trabecular bone volume measured by histological analysis was dramatically increased in transgenic mice compared with their wild-type littermates. The enhanced bone formations in the transgenic mice appear to result from increase osteoblast activities as the expressions of four osteoblast markers - alpha 1 type 1 collagen, osteocalcin, alkaline phosphatase and phex were significantly higher in transgenic fetuses than that in their wild-type littermates. These results suggest that over-expression of BMP11 propeptide stimulates bone formation by increasing osteoblast cell functions. (C) 2011 Elsevier Inc. All rights reserved.

To evaluate the effect of probiotics in pigs fed a high fat/high fructose/high cholesterol (obesogenic) diet, three groups of eight recently weaned Ossabaw pigs were maintained on the obesogenic diet and fed 1) 2 x 1010cfu of Bb12 or 2) a probiotic-free vehicle placebo daily, and compared to 3) pigs fed a control basal diet (CD). The obesogenic diet with or without Bb12 increased weight gain, abdominal circumference, total body fat deposition, and serum levels of LDH:HDL cholesterol, and analysis of the intestinal microbiota revealed less bacterial diversity in the lumen and mucosa compared to pigs fed the CD. Notably, morphometric measurements of adipocytes in abdominal fat depots of pigs fed the obesogenic diet and probiotic-free placebo showed a significant increase in size compared to pigs fed CD or the obesogenic diet and Bb12. Systemic leptin levels, however, were significantly increased only in pigs fed the obesogenic diet and Bb12 compared to pigs in the other groups. The juvenile Ossabaw pig fed an obesogenic diet represents a model to evaluate feeding probiotics or other bioactive dietary components on development of obesity, especially since recent studies demonstrated a significant relationship between adipocyte size and % fat gain in the upper body of overfed humans. (Funded by USDA/ARS).

A study was conducted to appraise a new EchoMRI™ device for body composition analysis (BCA) of infants and to compare it with dual energy X-ray absorptiometry (DXA), using chemical analysis as a reference method.The calibration part of the study included cross-validation comparisons between EchoMRI™ measurements of awake, anesthetized and dead piglets of the calibration set. It also included comparison of two different approaches to refining the calibration of EchoMRI™, by low- or by high-dimensional linear regressions. Only the low-dimensional approach was applied to DXA.The validation part yielded EchoMRI™ accuracy of 27 g and 70 g for fat and total water, respectively, on piglets scanned while anesthetized, as compared with 24 g and 57 g, respectively, for DXA.EchoMRI™ precision was found to be 4 g and 7 g for fat and total water, respectively, for anesthetized piglets, as compared to 16 g and 14 g, respectively, for DXA. The differences between fat measurements of awake, anesthetized and dead piglets can be statistically significant, but are comparable in magnitude to random errors.To summarize: Characterization of random errors by CV, especially that of fat, is not suitable for BCA, whereas absolute errors or errors relative to total body weight can be applicable. Low- and high-dimensional regressions offer nearly the same accuracy improvements. Improved DXA and EchoMRI™ offer nearly the same accuracy, within 1% of weight in fat, while EchoMRI™ has better precision, within 0.2 % of weight in fat for anesthetized and dead piglets as compared to DXA's 0.5-0.6%.

A study was conducted to validate the use of a quantitative magnetic resonance (QMR) device for measuring the body composition of infants and neonates weighing <12 kg using the pig as a model. A total of 25 piglets weighing between 2 and 12 kg were studied. Body composition was assessed by QMR, dual-energy x-ray absorptiometry (DXA), and whole-body chemical analysis (CA) of carcass for lipid and water content. The precision, mean and SD of repeated measurements, of QMR to estimate fat mass (FM), lean mass (LM), and total body water (TBW) for five consecutive scans with reposition was 12.5, 32.0, and 36.0 g, respectively. QMR measures of FM, LM, and TBW were highly and significantly correlated with CA of carcass. In terms of accuracy, mean difference between QMR and CA (percent of mean value for CA), QMR overestimated FM by 40 g (4.7%), overestimated LM by 114.9 g (2.1%), and underestimated TBW by 134.6 g (3.1%). This study concludes that QMR provides precise and accurate measures of FM, LM, and TBW in piglet weighing up to 12 kg. These results suggest that QMR can provide valuable body composition data in longitudinal studies in infants.

During studies of the growth of neonatal piglets it is important to be able to accurately assess changes in body composition. The purpose of this study was to compare the in vivo measurements of body composition of small piglets using QMR and DXA and to validate those results by chemical analysis. A total of 25 pigs (1.7 ‐ 4.1 kg) were measured by QMR (EchoMRI) and by DXA (Lunar Prodigy). Both instruments were tested as supplied by the manufacturer, with QMR measuring total body fat, water, and lean and DXA measuring total body fat and lean. The chemical measure of total body fat was highly correlated with both the QMR (r = 0.96) and DXA (r = 0.98) fat measurements and the correlation (r) between QMR and DXA was 0.93. However, DXA overestimated the amount of fat by 31% (P<0.05), whereas QMR overestimated the amount of fat by only 3.4% (P>0.05). The chemical measure of total body water was highly correlated with both the QMR (r = 0.98) and DXA (r = 0.99) measurements of total body lean mass and the correlation between QMR and DXA was 0.99. The DXA measure of total body lean was 18% more (P<0.05) than that measured by QMR. The QMR measure of total body water was 8% less (P>0.05) than that measured by chemical analysis. These studies indicate that QMR represents a potentially accurate method for measuring the body composition of piglets offers the advantages of no exposure to X‐ray radiation and measurement without the pig being anesthetized.

Synthesized beta 1- and beta 2-pentapeptide sequences corresponding to published adrenoceptor transmembrane activation site subtypes were investigated in vitro for selectivity in association for drug ligands of known selectivity. Both nuclear magnetic resonance spectroscopy and molecular mechanics demonstrated that structural differences among the corresponding pentapeptide activation-site sequences can explain agonist selectivity. Results suggest the agonists bind across the activation site loop on the second transmembrane alpha-helix by dipole/dipole interactions between a ligand and the peptide. Since electrostatic interactions within the membrane may determine the rate of intercellular ion flux, agonist association across the activation site sequence could thereby decrease electrostatic resistance to positive ion flux into the cell. Interactions between the peptides and the ligands may provide insight into the structures and mechanisms involved in association of ligands for the identical sequences on the beta-adrenoreceptors.

Abstract. Research was conducted to determine if directing expression of insulin-like growth factor I (IGF1) specifically to striated muscle would enhance lean muscle growth in swine. At 120 kg BW, 25 transgenic (T) and 26 control (C) pigs were sacrificed to evaluate carcass composition. T-pigs had lower percentages of fat and higher percentages of lean tissues than C-pigs for the overall carcass and each carcass region (P ≤ 0.002 for each). Expression of the IGF1 transgene did not alter the percentages of the three fiber types in the five skeletal muscles, however, fiber areas of longissimus dorsi muscle (LM) and serratus ventralis were larger (P ≤ 0.031) in T- than in C-pigs. In Tpigs the relative abundance of IGF1 mRNA in gastrocnemius, gluteus medius, LM, and the average for all five skeletal muscles (ASM) was positively (P ≤ 0.011) correlated with percentage of carcass lean (r = +0.597 to 0.804), whereas the relative abundance of IGF1 mRNA in the LM and the ASM was negatively (P ≤ 0.047) correlated with average backfat (r = −0.546 and −0.488, respectively). Based on these results we conclude that expression of IGF1 specifically in skeletal muscle had a positive effect on carcass composition of swine.

The purpose of this study was to measure the growth and body composition of pigs during normal or compensatory growth from 60 to 100 kg, without (cont) or with ractopamine (rac) supplementation (20 mg/kg of diet). Thirty-four pigs were scanned by dual X-ray absorptiometry (DXA) for body composition analysis at a starting weight of 61.4 ± 0.3 kg and at a final weight of 100.4 ± 0.5 kg. Half the pigs were fed ad libitum throughout (8 cont and 9 rac). The other half were fed at maintenance for 8 weeks and then scanned again by DXA. Following the maintenance feeding, the pigs were fed ad libitum (9 cont and 8 rac) to the final weight. Compensatory growth resulted in a 30% increase in the rate of weight gain (1.23 v. 0.94 kg/day, P < 0.05), including a 44% increase in the rate of lean tissue deposition (0.90 v. 0.62 kg/day, P < 0.05), but no change in the rate of fat deposition (0.31 v. 0.30 kg/day, P > 0.05). Feeding rac resulted in a 13% increase in the rate of weight gain (1.15 v. 1.02 kg/day, P < 0.05), consisting of a 29% increase in the rate of lean tissue deposition (0.86 v. 0.67 kg/day, P < 0.05) and an 18% reduction in the rate of fat deposition (0.27 v. 0.33 kg/day, P < 0.05). The effects of ractopamine on the rates of fat and lean tissue deposition were similar for pigs continuously fed ad libitum and those experiencing compensatory growth. Both compensatory growth and the addition of ractopamine to the diet resulted in an improvement in efficiency of protein deposition; however, ractopamine also resulted in a reduction in the efficiency of energy deposition. For both growth rate and lean tissue deposition, there was an additive effect for ractopamine and compensatory growth. Thus, feeding ractopamine will enhance the growth and body composition during compensatory growth in swine.

Pigs were raised on six isotopically controlled diets to examine the dietary macronutrients used in the synthesis of bulk bone isochemical components (apatite, collagen and lipids) and individual compounds (bone fatty acids, cholesterol and amino acids from collagen). delta C-13 values of apatite and bulk bone lipids reflected those of the whole diet, with Delta C-13(apatite-whole diet)=10.2 +/-1.3% and Delta C-13(bone lipids-whole diet)=-2.4 +/-0.7%. A wide variation observed in the Delta C-13(collagen-whole diet) values (0.5 to 6.1%) was hypothesized to reflect the relative importance of (i) the direct incorporation of essential amino acids, and (ii) the balance between direct incorporation and de novo synthesis of non-essential amino acids. Linear regression (n=6) was used to assess the relationship between the delta C-13 values of whole diet and bulk bone components and individual compounds. Whole diet delta C-13 values showed a strong correlation with those of bone cholesterol (R-2=0.85) and glutamate (R-2=0.96) in collagen. The essential amino acids leucine (Delta (13)C(collagen leu diet leu)0.5 +/-1.2%) and phenylalanine (Delta C-13(collagen phe-diet phe)=-0.6 +/-0.6%) showed little isotopic fractionation between diet and bone collagen.

The purpose of this study was to evaluate the use of a cross-sectional scan as an alternative to the total body DXA scan for predicting the body composition of pigs in vivo. A total of 212 pigs (56 to 138 kg live body weight) were scanned by DXA. The DXA scans were analyzed for percentage fat and lean in the total body and in 14 cross-sections (57.6 mm wide): 5 in the front leg/thoracic region, 4 in the abdominal region, and 5 in the back leg region. Regression analysis was used to compare total body and cross-sectional DXA results and chemical analysis of total body fat, protein and water. The relation (R2) between the percentage fat in individual slices and the percentage of total body fat measured by DXA ranged from 0.78 to 0.97 and by chemical analysis from 0.71 to 0.85, respectively. The relation between the percentage of lean in the individual slices and chemical analysis for percentage of total body protein and water ranged from 0.48 to 0.60 and 0.56 to 0.76, respectively. These results indicate that total body composition of the pig can be predicted (accurately) by performing a time-saving single-pass cross-sectional scan.

A unit cell in which three isomers are in an l configuration and one is in a d configuration is inherently asymmetrical. For ldll mixtures of amino acids with identical chemical structures (apart from chirality), the inter- and intramolecular interactions observed from the 13C CP/MAS NMR spectra are even larger than those which have been observed with mixtures of diastereoisomers in the solid state. This occurs even though the chemical composition of these molecular clusters consists only of nearest neighbor enantiomers. Because d and l isomers have identical chemical shifts, changes in chemical shift and peak intensities of these asymmetrical solid mixtures cannot be unamiguously assigned to either the d or one of the l isomers. In lldl mixtures of amino acids in which half is l isomers and the other half is dl isomers, the NMR spectra clearly depend upon which amino acid contains the d isomer. Any further structural interpretation of these molecular clusters is equivocal without assigning chemical shifts to the d isomer (or alternatively designated the R, [−] or [+] isomer). Both more rigorous mathematical analysis and new NMR experiments are required which link interactions at chiral centers with NMR spectra of lldl mixtures in the solid state.