BIA on Animals: • Cattle• Lamb• Fish• Other

BIA on Cattle

J Anim Sci. 1999 Nov;77(11):2965-70.

Marchello MJ, McLennan JE, Dhuyvetter DV, Slanger WD.

Animal and Range Sciences Department, North Dakota State University, Fargo 58105-5727, USA. mmarchel@ndsuext.nodak.edu

Two experiments were performed to develop prediction equations of saleable beef and to validate the prediction equations. In Exp. 1, 50 beef cattle were finished to typical slaughter weights, and multiple linear regression equations were developed to predict kilograms of trimmed boneless, retail product of live cattle, and hot and cold carcasses. A four-terminal bioelectrical impedance analyzer (BIA) was used to measure resistance (Rs) and reactance (Xc) on each animal and processed carcass. The IMPS cuts plus trim were weighed and recorded. Distance between detector terminals (Lg) and carcass temperature (Tp) at time of BIA readings were recorded. Other variables included live weight (BW), hot carcass weight (HCW), cold carcass weight (CCW), and volume (Lg2/Rs). Regression equations for predicting kilograms of saleable product were [11.87 + (.409 x BW) – (.335 x Lg) + (.0518 x volume)] for live (R2 = .80); [-58.83 + (.589 x HCW) – (.846 x Rs) + (1.152 x Xc) + (.142 x Lg) + (2.608 x Tp)] for hot carcass (R2 = .95); and [32.15 + (.633 x CCW) + (.33 x Xc) – (.83 x Lg) + (.677 x volume)] for cold carcass (R2 = .93). In Exp. 2, 27 beef cattle were finished in a manner similar to Exp. 1, and the prediction equations from Exp. 1 were used to predict the saleable product of these animals. The Pearson correlations between actual saleable product and the predictions based on live and cold carcass data were .91 and .95, respectively. The Spearman and Kendall rank correlations were .95 and .83, respectively, for the cold carcass data. These results provide a practical application of bioelectrical impedance for market-based pricing. They complement previous studies that assessed fat-free mass.

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J Anim Sci. 1994 Dec;72(12):3118-23.

Marchello MJ, Slanger WD.

Department of Animal and Range Sciences, North Dakota State University, Fargo 58105.

Multiple linear regression equations predicting total skeletal muscle (TM) and total skeletal fat-free muscle (TFFM) weight were developed from data of 33 beef cows. Animals varied in weight (385 to 749 kg), age (3 to 10 yr), and fatness (.13 to 2.54 cm). A four-terminal impedance meter/plethysmograph measured resistance and reactance on the live animals, exsanguinated (bled) animals, and on the subsequent hot and cold carcasses. Stainless steel, sterile needles (20-gauge) were used as electrodes. They were inserted to depths of 12.7 mm for measurements made before and after exsanguination and to 25.4 mm for carcass measurements. Cold carcass resistance and reactance were measured a second time using 13-gauge needles inserted to depth of 76.2 mm. Distance between detector electrodes was measured. Carcass sides were physically separated into muscle, fat, and bone. Chemical composition (moisture, protein, and fat) was determined on the muscle portion. Equations predicting TM weight from live, bled, hot carcass, and cold carcass data had adjusted R2 values of .90, .96, .94, and .92, respectively. Analogous adjusted R2 values for TFFM weight were .87, .93, .90, and .87. Resistance was a predictor variable in all equations. The use of larger needles resulted in higher adjusted R2 values and inclusion of reactance as a predictor variable. Mallows Cp values were close to the ideal value of the number of independent variables in the prediction equations plus one (1).(ABSTRACT TRUNCATED AT 250 WORDS)

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BIA on Lamb

J Anim Sci. 2004 Nov;82(11):3144-53.

Survival, growth, and carcass traits of F1 lambs.Freking BA, Leymaster KA.

ARS, USDA, U.S. Meat Animal Research Center, Clay Center, NE 68933-0166, USA.

The objectives of this study were to estimate effects of sire breed (Dorset, Finnsheep, Romanov, Texel, and Montadale), and dam breed (Composite III and Northwestern whiteface) on survival, growth, carcass, and composition traits of F1 lambs. Effects of mating season (August, October, and December) were estimated for survival and growth traits. Data were collected on 4,320 F1 lambs sired by 102 purebred rams over 3 yr. Birth weight was recorded on all lambs, and subsequent BW were adjusted to 56 (weaning), 70, and 140 d of age (n = 3,713, 3,654, and 3,579 observations, respectively). Survival of dam-reared progeny (n = 4,065) to weaning was recorded. Each year, wethers from October matings were slaughtered in three groups at 25, 29, and 33 wk of age to obtain carcass data (n = 546). In addition to standard carcass traits, resistive impedance measurements were recorded on the warm carcass to predict lean mass. Dam breed (P = 0.37) did not influence lamb survival to weaning, but sire breed (P < 0.05) was important. Romanov-sired lambs excelled in survival rate to weaning (94.1%), followed by Finn-sheep (93.0%), Texel (90.7%), Dorset (90.0%), and Montadale (89.1%) sired progeny. Lower (P < 0.01) postweaning growth rate was observed for Texel (267 g/d) and Finnsheep (272 g/d) sired progeny than for Dorset (285 g/d), Montadale (282 g/d), and Romanov (278 g/d) sired progeny. Sire breed and dam breed were generally significant for most carcass traits. Breed differences in distribution of carcass fat and carcass shape were detected; however, carcass composition was similar for all sire breeds when compared at a constant carcass weight. When evaluated at a constant 12th-rib fat depth, carcasses of lambs from Finnsheep, Romanov, and Texel sires produced 1 to 1.5 kg less (P < 0.001) predicted lean mass per lamb than carcasses of lambs from Dorset and Montadale sires. These experimental results provide information about the direct breed effects for survival, growth, and carcass traits of these breeds and their potential use in crossbreeding systems.

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J Anim Sci. 1996 Nov;74(11):2672-8.

Berg EP, Neary MK, Forrest JC, Thomas DL, Kauffman RG.

Purdue University, West Lafayette, IN 47907-1151, USA.

Market weight lambs, average weight 52.5 kg (+/-6.1), were used to evaluate nontraditional live animal measurements as predictors of carcass composition. The sample population (n = 106) represented U.S. market lambs and transcended geographic location, breed, carcass weight, yield grade, and production system. Realtime ultrasonic (RU) measurements and bioelectrical impedance analysis (BIA) were used for development and evaluation of prediction equations for % boneless, closely trimmed primal cuts (BCTPC), weight or % of dissected lean tissue (TDL), and chemically derived weight or % fat-free lean (FFL). Longitudinal ultrasonic images were obtained parallel to the longissimus thoracis et lumborum (LTL), positioning the last costae in the center of the transducer head. Images were saved and fat and LTL depths were derived from printed images of the ultrasonic scans. Bioelectrical impedance analysis was administered via a four-terminal impedance plethysmograph operating at 800 microA at 50 kHz. Impedance measurements of whole-body resistance and reactance were recorded. Prediction equations including common linear measurements of live weight, heart girth, hindsaddle length, and shoulder height were also evaluated. All measurements were taken just before slaughter. Bioelectrical impedance measurements (as compared to RU and linear measurements) provided equations for %BCTPC, TDL, %TDL, FFL and %FFL with the highest R2 and lowest root mean square error. Even though BIA provided the best equations of the three methodologies tested, prediction of proportional yield (%BCTPC, %TDL, and %FFL) was marginal (R2 = .296, .551, and .551, respectively). Equations combining BIA, RU, and linear measurements greatly improved equations for prediction of proportional lean yield.

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BIA on Fish

Can. J. Fish. Aquat. Sci. 62(2): 269.275 (2005)

Nonlethal estimation of proximate composition in fish

M. Keith Cox and Kyle J. Hartman

NRC Canada

The need to precisely measure growth is a common denominator in many fisheries studies, but growth measures other than total masses or lengths are nearly nonexistent because more precise measurements such as body composition analysis are often too difficult and time consuming. Here, we present a means of estimating body composition in fish quickly, and after validation, without the need to sacrifice the animal. Models built with brook trout (Salvelinus fontinalis) were linear with strong validation group relationships (R² > 0.96) for composition parameters including water, protein, fat, fat-free, and dry masses. Subject responses to bioelectrical impedance analysis were minimal, with only slight bruising (p < 0.001) with no effect on swimming, color, bleeding, or feeding. The model was also tested on the water and dry masses of 10 warmwater fish species and found to have strong correlations (R² > 0.86), suggesting that more general relationships may exist. Nonlethal estimation of body composition using bioelectrical impedance analysis will permit increased precision in bioenergetics energy flow and compositional studies as well as permit study of community energetics and condition on spatial and temporal scales not previously possible.

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Development of Bioelectrical Impedance Analysis (BIA) for a rapid assessment of fish condition

Steve Pothoven, et al.

National Oceanic and Atmospheric Administration — Great Lakes Environmental Research Laboratory

This project focuses on the further development of an innovative technique, bioelectrical impedance analysis (BIA), for the rapid, cost-effective, accurate, and non-lethal measure of proximate body composition (i.e. lipids, energy density) of fish collected in the field or laboratory. BIA instantaneously measures the resistance and reactance (capacitance) along the length of the fish, which then can be used to quantify proximate body composition. The study will focus on generating necessary calibration equations for three commercially important Great Lakes fishes, yellow perch, lake whitefish, and walleye, which differ in terms of mass-specific lipid content, energy density, and total body size. Ultimately, this study will enhance efforts to assess the condition (health) of these species in a rapid, cost-effective manner.

In 2005, we collected 41 yellow perch and 10 walleye from Lake Erie for BIA analysis. Preliminary results from 2005 indicate strong relationships between BIA resistance measures for yellow perch relative to total calories (r² = 0.87) and water content (r² = 0.88) (Fig 1). Given these positive findings, BIA holds great potential for Great Lakes researchers and agencies that desire the ability to rapidly and accurately quantify fish condition and health.

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Aquaculture 271 (2007) 432-438

M. Duncan, S.R. Craig, Angela N. Lunger, D.D. Kuhn, G. Salze, E. McLean

Virginia Tech Aquaculture Center, 1 Plantation Road, Blacksburg, VA 24061-0321, USA

Sixty juvenile cobia (Rachycentron canadum; 28.3±0.13 g wet wt) were randomly distributed into each of 12 tanks in a recirculation unit (n=5 tank-1). Fish were fed one of two diets (47:8 or 47:20 protein:lipid) at 6-8% body wt d-1 for 6 weeks. Each week, the composition of fish (n=5) from each dietary treatment was calculated by measuring the impedance (resistance and reactance) of a current (x µAAC and kHz) passed through a live animal. Electrodes were positioned at morphologically discrete points on the dorsal left hand side of the animal. After bioimpedance (BIA) assessment, the identical fish were sacrificed and their body composition determined using traditional, chemical methods. Results generated by chemical analyses were regressed against BIA data. Linear regression analysis was performed utilizing compositional analysis (protein, lipid and ash) as the observed values and BIA assessment for the predicted. Regressions for each body composition parameter produced high correlations in all relationships: resistance (in parallel) and protein (adj. R²=0.9569), resistance (in parallel) and total body water (adj. R²=0.9894), reactance (in parallel) and total body ash (adj. R²=0.8547), reactance (in series) and dry matter (adj. R²=0.9272) and reactance (in series) and fat-free mass (adj. R²=0.9916). The F value tests (Pb0.0001) revealed significant correlations between the independent and dependent variables for each body composition parameter. Correlations for each regression indicate strong linear relationships between impedance and proximate analysis variables with values of 1:1. This indicates that this BIA methodology can be utilized as an inexpensive, non-lethal, on the farm determination of proximate composition.

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Fish. Res. (2008)

Jay Willis, Alistair J. Hobdaya

Tagging fish without gathering physiological informationmay be awasted opportunity.We tested bioelectrical impedance analysis (BIA) for measurement of relative condition of southern bluefin tuna (Thunnus maccoyii) during conventional tagging at sea. We refined the equipment and method by measurement of 360 fish during conventional and acoustic tagging. Our results demonstrate that BIA is an accurate measure of condition for southern bluefin tuna in the same way it has been shown to be for metabolic condition and composition in other vertebrates including humans. Further, there is sufficient variation in BIA measures of the natural population to give meaningful measures of both metabolic condition and composition between groups at different times and developmental stages. Condition of tuna in this study may be related to the ocean environment just prior to measurement. BIA meets the necessary objectives for measuring fish condition during tagging as it is shown to be harmless, reliable, quick, and effective and does not disrupt conventional tagging operations. In the light of these results this type of condition measurement should be taken wherever possible in future tagging operations for this and other similar species, which will generate new insight into the ecological challenges faced by pelagic fishes. The ability to relate recent ocean environments and subsequent patterns in fish survival may lead to changes in the way tagging data is interpreted.

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J Physiol Anthropol Appl Human Sci. 2004 May;23(3):93-9. Fisheries Research 93 (2008) 64-71.

Jay Willisa^a and Alistair J. Hobday^b

^aSchool of Zoology & QMS, University of Tasmania, Hobart, Australia

^bCSIRO Marine and Atmospheric Research, Castray Esplanade, Hobart, Tasmania, Australia

Tagging fish without gathering physiological information may be a wasted opportunity. We tested bioelectrical impedance analysis (BIA) for measurement of relative condition of southern bluefin tuna (Thunnus maccoyii) during conventional tagging at sea. We refined the equipment and method by measurement of 360 fish during conventional and acoustic tagging. Our results demonstrate that BIA is an accurate measure of condition for southern bluefin tuna in the same way it has been shown to be for metabolic condition and composition in other vertebrates including humans. Further, there is sufficient variation in BIA measures of the natural population to give meaningful measures of both metabolic condition and composition between groups at different times and developmental stages. Condition of tuna in this study may be related to the ocean environment just prior to measurement. BIA meets the necessary objectives for measuring fish condition during tagging as it is shown to be harmless, reliable, quick, and effective and does not disrupt conventional tagging operations. In the light of these results this type of condition measurement should be taken wherever possible in future tagging operations for this and other similar species, which will generate new insight into the ecological challenges faced by pelagic fishes. The ability to relate recent ocean environments and subsequent patterns in fish survival may lead to changes in the way tagging data is interpreted.

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BIA on Other Animals

J Nutr. 2001 Apr;131(4):1302-8.

Yokoi K, Lukaski HC, Uthus EO, Nielsen FH.

U.S. Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, North Dakota 58202-9034, USA. kyokoi@gfhnrc.ars.usda.gov

The effect of dietary sulfur amino acids on bioelectric properties was studied in rats by using bioimpedance spectroscopy. Weanling rats were assigned to one of 12 groups in a factorially arranged experiment with dietary variables of supplemental sulfur amino acid (none, 10 g DL-methionine/kg or 10 g DL-homocystine/kg), pyridoxine hydrochloride (0 or 7.5 mg/kg) and nickel (0 or 1 mg/kg). After 9 wk of feeding, 20-h urine specimens were collected from food-deprived rats for measurements of creatinine, and then bioimpedance was measured with multifrequency (Hydra ECF/ICF 4200) and single-frequency (RJL Systems model 101) analyzers. Urinary creatinine excretion was measured by intracellular water (ICW), total body solid and urinary volume (R2 = 0.675). Extracellular water (ECW) did not add significantly to the model. Rats fed methionine had significantly lower total body water, ICW and ECW than rats fed no supplemental sulfur amino acid. Rats fed homocystine had significantly lower ECW and a significantly higher ratio of ICW to ECW. Rats fed methionine or homocystine had significantly lower capacitance corrected for body length and ICW than those fed no supplemental sulfur amino acids. These results suggest that dietary homocystine changes the distribution of body water and that sulfur amino acids can affect membrane porosity and/or membrane thickness.

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Med Biol Eng Comput. 1998 Sep;36(5):604-7.

Kohli KS, Rai DV, Jindal VK, Goyal N.

Department of Biophysics, Panjab University, Chandigarh, India.

A computer assisted AC impedance system is used to measure the DC voltage-current (V-I) characteristics and AC impedance of a goat eye lens using a two-probe Ag-AgCl electrode system. The measurement of the V-I characteristics shows that when a DC voltage from 0 mV to 30 mV is applied, the resultant current decreases from an initial value of 0.58 microA to 0.006 microA. However, when the voltage is increases beyond 30 mV, the current increases and reaches a value of 0.9 microA at 100 mV. The data on the frequency response (0.01-10 Hz) of the impedance of lens tissue show an inverse relationship with frequency. The effect of various DC voltages, namely 0, 30, 50, 100 and 200 mV, on the impedance of the eye lens is also investigated over a frequency range of 0.01-10 Hz. The measurement results for both V-I characteristics and AC impedance further suggest the presence of a 30 mV voltage compartment in the goat eye lens.

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J Anim Sci. 1992 Nov;70(11):3443-50.

Marchello MJ, Slanger WD.

Animal and Range Sciences Department, North Dakota State University, Fargo 58105.

The objective of this research was to make available bioelectrical impedance technology for the prediction of kilograms of lean and kilograms of fat-free muscle of Boston butts. Seventy butts were removed from 70 pork carcasses according to standard procedures (NAMP, #406), with the exception that the fat was not removed. After the weight in kilograms (BUTT) and internal temperature in degrees centigrade (TEMP) were recorded, each butt was measured for resistance (Rs, ohms), reactance (Xc, ohms), and distance (L, centimeters) between detector terminals four different ways: parallel or perpendicular to the top of the carcass and on either lean surface or fat surface of the cut. Each cut was physically separated into lean, fat, and bone. Chemical composition (moisture, protein, and fat) was determined on the lean portion. Variable selection analysis was used to develop equations for predicting kilograms of lean and kilograms of fat-free muscle of Boston butts. Results of measurements of the four sites were quite similar; however, measuring perpendicularly on the lean surface is recommended. The prediction equation for kilograms of lean from measurements thus taken is as follows: .461-.0304 x TEMP + .576 x BUTT – .0118 x Rs + .00845 x Xc + .0630 x L. The respective coefficients of these independent variables for predicting kilograms of fat-free muscle are .537, -.0415, .479, -.0139, .00804, and .0764. In an industry application of these coefficients, recording temperature would not be imperative because the temperature range would be sufficiently narrow to render temperature of little practical influence when separating butts according to leanness.(ABSTRACT TRUNCATED AT 250 WORDS)

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Journal of Mammalogy, 87(4):717-722, 2006

JUSTIN A. PITT,* SERGE LARIVIE`RE, AND FRANCOIS MESSIER

Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada (JAP, FM) Cree Hunters and Trappers Income Security Board, Edifice Champlain, Bureau 110, 2700 Boulevard Laurier, Sainte-Foy, Quebec G1V 4K5, Canada (SL)

Body condition directly affects survival and reproduction by animals, so its effects on fitness represent an important component of animal ecology. Traditionally, ecologists have relied on direct chemical analysis or morphometric indices to assess body condition. We examined the ability of morphometric indices and bioelectrical impedance analysis to estimate body condition of raccoons (Procyon lotor) and assessed the need for species-specific models. Morphological indices were poor estimators of body condition; the best model explained 62% of the variation of fat and had a high SE (r2 1/4 0.62, SE 1/4 0.52, P , 0.001). Bioelectrical impedance analysis proved to be a reliable way to noninvasively estimate body condition. Models for lean dry mass and total body water were used to accurately estimate body fat (r2 1/4 0.94, SE 1/4 0.16, P , 0.001). Body fat estimates derived through models for a similar species performed better than morphometric indices but did not achieve the accuracy of the species-specific model. Examination of our data highlights the need to validate models used to estimate body condition before use.

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J. Nutr. 132: 1760S-1762S, 2002.

Denise A. Elliott,2,3 Robert C. Backus, Marta D. Van Loan* and Quinton R. Rogers

Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, CA and *U.S. Department of Agriculture Western Human Nutrition Research Center, Davis, CA

Multifrequency bioelectrical impedance analysis (MFBIA4) is emerging as a simple, noninvasive routine clinical procedure that allows the rapid and frequent evaluation of total body water (TBW) and extracellular water (ECW) (1) The application of MF-BIA to determine TBW and ECW in adult healthy cats has been evaluated (2). In that study, the MF-BIA prediction of TBW in 20 healthy adult cats was r _ 0.84, and the standard error of the estimate (SEE) was 0.26 L, or 9.96%. Similarly, the MF-BIA prediction of ECW in 20 healthy adult cats was r _ 0.91, and SEE was 0.07 L, or 6.87%. The purpose of this study was to cross-validate the MF-BIA method by comparing the relationship between MF-BIA with TBW determined by deuterium oxide (D2O) dilution and ECW determined by bromide (Br) space in a group of cats with a diverse range of body weights and body condition scores.

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J. Anim. Sci. 1999. 77:2965-2970

M. J. Marchello, J. E. McLennan, D. V. Dhuyvetter, and W. D. Slanger

Animal and Range Sciences Department, North Dakota State University, Fargo 58105-5727

Two experiments were performed to develop prediction equations of saleable beef and to validate the prediction equations. In Exp. 1, 50 beef cattle were finished to typical slaughter weights, and multiple linear regression equations were developed to predict kilograms of trimmed boneless, retail product of live cattle, and hot and cold carcasses. A four-terminal bioelectrical impedance analyzer (BIA) was used to measure resistance (Rs) and reactance (Xc) on each animal and processed carcass. The IMPS cuts plus trim were weighed and recorded. Distance between detector terminals (Lg) and carcass temperature (Tp) at time of BIA readings were recorded. Other variables included live weight (BW), hot carcass weight (HCW), cold carcass weight (CCW), and volume (Lg2/Rs). Regression equations for predicting kilograms of saleable product were [11.87 + (.409 × BW) – (.335 × Lg) + (.0518 × volume)] for live (R2 = .80); [-58.83 + (.589 × HCW) (.846 × Rs) + (1.152 × Xc) + (.142 × Lg) + (2.608 × Tp)] for hot carcass (R2 = .95); and [32.15 + (.633 × CCW) + (.33 × Xc) – (.83 × Lg) + (.677 × vo1ume)] for cold carcass (R2 = .93). In Exp. 2, 27 beef cattle were finished in a manner similar to Exp. 1, and the prediction equations from Exp. 1 were used to predict the saleable product of these animals. The Pearson correlations between actual saleable product and the predictions based on live and cold carcass data were .91 and .95, respectively. The Spearman and Kendall rank correlations were .95 and .83, respectively, for the cold carcass data. These results provide a practical application of bioelectrical impedance for market-based pricing. They complement previous studies that assessed fat-free mass.

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J. Anim . Sci. 1994. 72:3118-3123

M. J. Marchello and W. D. Slanger

Department of Animal and Range Sciences, North Dakota State University, Fargo 58105

Multiple linear regression equations predicting total skeletal muscle (TM) and total skeletal fat-free muscle (TFFM weight were developed from data of 33 beef cows. Animals varied in weight (385 to 749 kg), age (3 to 10 yr), and fatness (.13 to 2.54 cm). A four-terminal impedance meter/plethysmograph measured resistance and reactance on the live animals, exsanguinated (bled) animals, and on the subsequent hot and cold carcasses. Stainless steel, sterile needles (20-gauge) were used as electrodes. They were inserted to depths of 12.7 mm for measurements made before and after exsanguinations and to 25.4 mm for carcass measurements. Cold carcass resistance and reactance were measured a second time using 13-gauge needles inserted to depth of 76.2 mm. Distance between detector electrodes was measured. Carcass sides were physically separated into muscle, fat, and bone. Chemical composition (moisture, protein, and fat) was determined on the muscle portion. Equations predicting TM weight from live, bled, hot carcass, and cold carcass data had adjusted R2 values of .90, .96, .94, and .92, respectively. Analogous adjusted R2 values for TFFM weight were 37, .93, .90, and .87. Resistance was a predictor variable in all equations. The use of larger needles resulted in higher adjusted R2 values and inclusion of reactance as a predictor variable. Mallows Cp values were close to the ideal value of the number of independent variables in the prediction equations plus one( 1). Results indicate that bioelectrical impedance technology is a rapid, nondestructive, and accurate method for determining TM and TFFM weight of beef cows and carcasses. This demonstrates that bioelectrical impedance has the potential to be used as a valuebased marketing tool. Because these measurements can be easily obtained on live animals with no detrimental effects, it has the potential to be used for the genetic selection of superior animals.

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Can. J. Zool. 77: 418-422 (1999)

W. Don Bowen, Carrie A. Beck, and Sara J. Iverson

W.D. Bowen.1 Marine Fish Division, Bedford Institute of Oceanography, Department of Fisheries and Oceans, Dartmouth, NS B2Y 4A2, Canada. C.A. Beck and S.J. Iverson. Department of Biology, Dalhousie University, Halifax, NS B3H 4J1, Canada.

Estimates of total body water (TBW) play an important role in studies of body composition and energetics in mammals. We evaluated bioelectrical impedance analysis (BIA) as a means of rapidly and inexpensively estimating TBW in 38 grey seals (Halichoerus grypus). Twenty-two males and 16 females, representing the range of body sizes in the population, were studied at Sable Island, Nova Scotia. Seals were chemically immobilized with Telazol during BIA measurement. TBW was determined by dilution of tritiated water. The mean difference in duplicate BIA measurements did not differ significantly from zero. BIA-measured resistance accounted for 83% of the variation in TBW over a range of body masses from 38.5 to 294 kg. Bioelectrical conductor volume (length2/resistance) accounted for 97% of the variation in TBW. Average error in predicting TBW was +0.10% for a validation set of nine animals, but errors in predicting TBW of individual seals were up to 25%. Our results indicate that BIA measurements can be a valuable adjunct to the use of isotope dilution for estimating TBW in chemically immobilized grey seals; however, individual estimates may be associated with varying degrees of error.

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Meat Science 72 (2006) 43-46

A. Daza a,*, A. Mateos a, I. Ovejero a, C.J. LoŽpez Bote b

a Departamento de ProduccioŽn Animal, E.T.S de Ingenieros AgroŽ nomos, Universidad PoliteŽcnica de Madrid, Spain
b Departamento de ProduccioŽn Animal, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid, Spain

Twelve barrow Iberian pigs with an average weight at slaughter of 109.2 kg were used to evaluate bioelectrical impedance procedures to predict the body composition of live pigs. Twelve hours before slaughter pigs were weighed, and a four-terminal body composition analyser (Model BIA-101, RJL Systems, Detroit, MI) was utilized to determine resistance (Rs in X) and reactance (Xc in X). The length values (L in cm) were measured between detector electrodes with a flexible steel tape. Twenty four hours after slaughter the left side of each carcass was separated using a scalpel into fat, lean, bone and skin. Multiple regression equations for estimating lean, fat, bone and skin amounts and lean, fat, bone and skin proportions with respect to slaughter weight were calculated. The live weight (LW) and L independent variables predicted 85.3% and 64.3% of the variability of the lean amount and lean proportion, respectively. The LW, Xc and L variables accounted for 96% and 91.6% of the variation in fat quantity and fat proportion, respectively. The LW and Rs accounted for 58.9% of the variation in bone amount, and the same variables predict 79.1% of the variability of bone percentage. The Rs and L variables explained 68% of the variability of skin quantity and LW, Rs and Xc predicted 83.1% of the variation of skin proportion. Results from this experiment indicate that bioelectrical impedance may be of interest for body composition prediction of live Iberian pigs.

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Marine Mammal Science 11 (3) , 301-313 doi:10.1111/j.1748-7692.1995.tb00286.x

JOHN P. Y.ARNOULD

British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 OET, U.K.

An attempt was made to develop simple, inexpensive, rapid means of determining body composition in Antarctic fur seals (Arctocephalus gazella). Measurements of total body water (TBW) and total body lipid (TBL), obtained by hydrogen isotope dilution, were compared to the results of bioelectrical impedance analysis (BIA) and morphometric indices of body condition in 52 adult females. TBW was weakly correlated with BIA measurements of resistance (v = -0.30, P < 0.03). Conductor volume (length2/resistance) was more highly correlated with TBW(r = 0.75, P < 0.0001) and the inclusion of mass into the predictive equation improved the correlation further (r = 0.95, P < 0.0001). A body condition index (mass/length) previously used in pinniped studies was positively correlated to TBL (r = 0.77, P < 0.0001) validating its use as a relative index of condition. However, body mass alone was highly correlated to TBW (r = 0.94, P < 0.0001) and appears to provide a simple, rapid means of estimating body composition in adult females. This technique may also be applicable to juvenile male Antarctic fur seals.

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Can. J. Zool. 77(3): 418-422 (1999)

W. Don Bowen, Carrie A. Beck, and Sara J. Iverson

Estimates of total body water (TBW) play an important role in studies of body composition and energetics in mammals. We evaluated bioelectrical impedance analysis (BIA) as a means of rapidly and inexpensively estimating TBW in 38 grey seals (Halichoerus grypus). Twenty-two males and 16 females, representing the range of body sizes in the population, were studied at Sable Island, Nova Scotia. Seals were chemically immobilized with Telazol during BIA measurement. TBW was determined by dilution of tritiated water. The mean difference in duplicate BIA measurements did not differ significantly from zero. BIA-measured resistance accounted for 83% of the variation in TBW over a range of body masses from 38.5 to 294 kg. Bioelectrical conductor volume (length2/resistance) accounted for 97% of the variation in TBW. Average error in predicting TBW was +0.10% for a validation set of nine animals, but errors in predicting TBW of individual seals were up to 25%. Our results indicate that BIA measurements can be a valuable adjunct to the use of isotope dilution for estimating TBW in chemically immobilized grey seals; however, individual estimates may be associated with varying degrees of error.

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Marine Mammal Science 10 (1) , 1-12 doi:10.1111/j.1748-7692.1994.tb00385.x

ROSEMARY GALES

Ocean Sciences Centre, Memorial University of Newfoundland, St. John’s, Newfoundland, Canada A1C 5S7, DEANE RENOUF11Ocean Sciences Centre, Memorial University of Newfoundland, St. John’s, Newfoundland, Canada A1C 5S7, G. A. J. WORTHY22Marine Mammal Research Program, Texas A&M University, 4700 Avenue U, Building 303, Galveston, Texas 77551, USA

Ocean Sciences Centre, Memorial University of Newfoundland, St. John’s, Newfoundland, Canada A1C 5S7 2Marine Mammal Research Program, Texas A&M University, 4700 Avenue U, Building 303, Galveston, Texas 77551, USA

Department of Parks, Wildlife and Heritage, GPO Box 44A, Hobart, Australia 7001.

Bioelectrical impedance analysis (BIA) measures resistance and reactance of a current as it passes through an organism. The validity of using BIA as a tool to measure body water content, and hence body composition and condition, was tested on harp and ringed seals. The resistance and reactance readings from BIA were compared to estimates of total body water (TBW) determined via tritiated water dilution. The relationship between resistance and TBW (% of body mass) was linear after logarithmic transformation and the two variables were highly correlated. We describe the electrode configuration and placements which provide reliable results in these seals. Our findings indicate that BIA has considerable potential as an inexpensive, rapid, and reliable technique for estimating body composition of phocid seals.

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Wildlife Research 24(6) 649 – 660 (1997)

Andrew P. Woolnough, William J. Foley, Christopher N. Johnson and Murray Evans

Several indirect methods for measuring body composition in a large herbivore, the southern hairy-nosed wombat (Lasiorhinus latifrons), were evaluated. Body composition was determined by whole-body chemical analysis of 15 wild-caught wombats, and compared with several indices of body fat: total body water measured by isotope dilution, bioelectrical impedance analysis (BIA), body-mass index, and a body- condition score. Total body water and total body fat (by soxhlet analysis) were highly correlated (r2 = 0.97, intercept s.e. = 1.00). Total body water measured by desiccation was highly correlated with isotope dilution space (r2 = 0.97, intercept s.e. = 0.43 for deuterium; r2 = 0.95, intercept s.e. = 0.44 for H218O). Percentage body fat by soxhlet analysis was highly correlated with total body water measured as deuterium dilution space (r2 = 0.83, intercept s.e. = 2.46). Multiple linear regression models using BIA plethysmograph measurements (resistance and impedance) and total body mass, were successful in predicting body fat (r2 = 0.90, s.e. = 1.99) and total body water (r2 = 0.90, s.e. = 1.64). Isotope-dilution techniques are the most accurate means of indirectly measuring total body water and total body fat, but at considerable expense of time and money. BIA offers reduced accuracy but at less cost and may be useful for measuring changes in body composition in populations of herbivores. Body-condition indices and scores correlate poorly with body fat, suggesting that their application as a means to predict body fat is limited.

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Wildlife Society Bulletin, Vol. 30, No. 3 (Autumn, 2002), pp. 915-921

Kris J. Hundertmark and Charles C. Schwartz

Estimation of body composition of wild ungulates yields important information regarding nutritional status of individuals and populations; yet, there are few suitable field techniques that are nondestructive, unbiased, precise, and quick to perform. We tested the suitability of bioelectrical impedance analysis (BIA) as an estimator of body composition of moose (Alces alces) for use in the field. A derived BIA variable, impedance volume, was a significant predictor of body fat (mass and percentage) and body water (mass and percentage) when sex was added to models as an indicator variable but explained only 48-57% of variation in composition. Best predictive models included impedance volume, sex, body mass, and a body mass × sex interaction. Due to difficulty measuring body mass of moose in the field, we also generated predictive models when body mass was replaced with a proxy tex-math$(text{length}times text{girth}^{2})$/tex-math. Predictive equations for body water were more precise than were those for body fat. Impedance estimates decreased as the subject’s hind leg was straightened, indicating that animal positioning must be standardized to minimize bias. Lack of precision made BIA unsuitable for estimating moose body fat in the field. BIA was a precise and quick estimator of body water in moose, but its limitations make it more suitable for the laboratory than the field.

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The Journal of Wildlife Management, Vol. 63, No. 1 (Jan., 1999), pp. 286-291

Robert J. Gau and Ray Case

The use of blood parameters to estimate nutritional condition of bears has yet to be validated with actual body compositions. We used bioelectrical impedance analysis (BIA) to accurately estimate the body composition of a free-ranging population of grizzly bears (Ursus arctos) from the central Arctic of the Northwest Territories (NWT), Canada. We then correlated their blood hematology and metabolite parameters, previously identified by other studies on black bears (U. americanus) and grizzly bears to be useful indicators of nutritional condition, to the percentage of total body fat determined by BIA. None of the examined blood parameters had a significant relation with total body fat levels that were free from the effects of activity, stress, or dietary changes. Thus, interpretations of a grizzly bear’s nutritional condition via the blood parameters we examined would be spurious.

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Ursus, 2004 pp. 161-171

Charles T. RobbinsA, Charles C. SchwartzB, and Laura A. FelicettiC

A. Department of Natural Resource Sciences and School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA,
B. Interagency Grizzly Bear Study Team, U.S. Geological Survey, Northern Rocky Mountain Science Center, Forestry Sciences Lab, Montana State University, Bozeman, MT 59717, USA,
C. School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA

The capability to understand the nutritional ecology of free-ranging bears has increased dramatically in the last 20 years. Advancements have occurred because (1) managers and biologists recognized the need to link habitat quality, productivity, and variability with bear movements, home ranges, and demographic parameters like reproductive output, survival, and population growth, and (2) several research teams are using new methods to build on the results of earlier field studies. Our ability to couple new field methods and empirical field research with controlled experiments using captive bears has been central to our increased understanding of bear nutrition. Newer methods include the use of stable isotopes to quantify assimilated diet and nutrient flows within ecosystems, bioelectrical impedance to measure body composition, and naturally occurring mercury to estimate fish intake. Controlled experiments using captive bears have been integral to developing methods, isolating specific variables by controlling the environment, and providing additional nutritional understanding necessary to interpret field observations. We review new methods and apply our increased understanding of bear nutritional ecology to 3 management issues: (1) the importance of salmon (Oncorhynchus spp.) to brown bears (Ursus arctos) in the Pacific Northwest, (2) the consequences of the closure of the Yellowstone garbage dumps to grizzly bears, and (3) the relocation of problem bears.

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Polar Bears International / AZA Bear TAG (February 2006)

B.A. Lintzenich, M.S., A.M. Ward, M.S., M.S. Edwards, Ph.D., M.E. Griffin, Ph.D., C.T. Robbins, Ph.D.

Cincinnati Zoo & Botanical Garden, Fort Worth Zoo, Smithsonian National Zoological Park, Purina Mills, Inc., Washington State University

Polar bears, the most carnivorous of the Ursidae family, prey primarily on ringed seals (Best, 1985; Derocher, et. al, 2000; Stirling and Archibald, 1977). When brought into captivity, maintaining their nutritional and mental health can be challenging. Due to the lack of indepth species-specific research, captive polar bear diets must be based on a combination of known requirements of related domestic animals, the successful captive polar bear diets, and nutrients consumed by healthy captive polar bears to formulate dietary recommendations. A balanced diet for captive bears could include a combination of nutritionally complete items (dry, raw, and/or gel), saltwater fish, bones, whole prey, produce, and enrichment food items. All bears should be offered a diet that would maintain appropriate body condition across all Seasons.

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These papers and abstracts of papers have been published in peer-reviewed journals. They may draw conclusions and discuss applications of Bioelectrical Impedance Analysis which have not been reviewed by the FDA. Statements made within them are the sole responsibility of the authors. Unless otherwise indicated, no material support was provided to the authors or study investigators by RJL Systems.