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PubMed2004

Energy expenditure of walking and running: comparison with prediction equations.

PURPOSE: This study established the published prediction equations for the energy expenditure of walking and running compared with the measured values. To make this comparison we first determined whether differences exist in energy expenditure for 1600 m of walking versus running, and whether energy expenditure differences occur due to being on the track or treadmill. METHODS: Energy was measured via indirect calorimetry in 24 subjects while walking (1.41 m.s(-1)) and running (2.82 m.s(-1)) 1600 m on the treadmill. A subgroup also performed the 1600-m run/walk on the track. The measured energy expenditures were compared with published prediction equations. RESULTS: Running required more energy (P < 0.01) for 1600 m than walking (treadmill: running 481 +/- 20.0 kJ, walking 340 +/- 14 kJ; track: running 480 +/- 23 kJ, walking 334 +/- 14 kJ) on both the track and treadmill. Predictions using the ACSM or Leger equations for running, and the Pandolf equation for walking, were similar to the actual energy expenditures for running and walking (total error: ACSM: -20 and 14.4 kJ, respectively; Legers walking: -10.1 kJ; Pandolf walking: -10.0 kJ). An overestimation (P < 0.01) for 1600 m was found with the McArdle's table for walking and running energy expenditure and with van der Walt's prediction for walking energy expenditure, whereas the Epstein equation underestimated running energy expenditure (P < 0.01). CONCLUSION: Running has a greater energy cost than walking on both the track and treadmill. For running, the Leger equation and ACSM prediction model appear to be the most suitable for the prediction of running energy expenditure. The ACSM and Pandolf prediction equation also closely predict walking energy expenditure, whereas the McArdle's table or the equations by Epstein and van der Walt were not as strong predictors of energy expenditure.

Adolescent↗
PubMed2006

Predicted exposures to steroid estrogens in U.K. rivers correlate with widespread sexual disruption in wild fish populations.

Steroidal estrogens, originating principally from human excretion, are likely to play a major role in causing widespread endocrine disruption in wild populations of the roach (Rutilus rutilus), a common cyprinid fish, in rivers contaminated by treated sewage effluents. Given the extent of this problem, risk assessment models are needed to predict the location and severity of endocrine disruption in river catchments and to identify areas where regulation of sewage discharges to remove these contaminants is necessary. In this study we attempted to correlate the extent of endocrine disruption in roach in British rivers, with their predicted exposure to steroid estrogens derived from the human population. The predictions of steroid estrogen exposure at each river site were determined by combining the modeled concentrations of the individual steroid estrogens [17beta-estradiol (E2), estrone (E1), and 17alpha-ethinylestradiol (EE2)] in each sewage effluent with their predicted dilution in the immediate receiving water. This model was applied to 45 sites on 39 rivers throughout the United Kingdom. Each site studied was then categorized as either high, medium, or low "risk" on the basis of the assumed additive potency of the three steroid estrogens calculated from data derived from published studies in various cyprinid fish species. We sampled 1,438 wild roach from the predicted high-, medium-, and low-risk river sites and examined them for evidence and severity of endocrine disruption. Both the incidence and the severity of intersex in wild roach were significantly correlated with the predicted concentrations of the natural estrogens (E1 and E2) and the synthetic contraceptive pill estrogen (EE2) present. Predicted steroid estrogen exposure was, however, less well correlated with the plasma vitellogenin concentration measured in the same fish. Moreover, we found no correlation between any of the end points measured in the roach and the proportion of industrial effluents entering the rivers we studied. Overall, our results provide further and substantive evidence to support the hypothesis that steroidal estrogens play a major role in causing intersex in wild freshwater fish in rivers in the United Kingdom and clearly show that the location and severity of these endocrine-disrupting effects can be predicted.

Animals↗
PubMed1996

The NIEHS Predictive-Toxicology Evaluation Project.

The Predictive-Toxicology Evaluation (PTE) project conducts collaborative experiments that subject the performance of predictive-toxicology (PT) methods to rigorous, objective evaluation in a uniquely informative manner. Sponsored by the National Institute of Environmental Health Sciences, it takes advantage of the ongoing testing conducted by the U.S. National Toxicology Program (NTP) to estimate the true error of models that have been applied to make prospective predictions on previously untested, noncongeneric-chemical substances. The PTE project first identifies a group of standardized NTP chemical bioassays either scheduled to be conducted or are ongoing, but not yet complete. The project then announces and advertises the evaluation experiment, disseminates information about the chemical bioassays, and encourages researchers from a wide variety of disciplines to publish their predictions in peer-reviewed journals, using whatever approaches and methods they feel are best. A collection of such papers is published in this Environmental Health Perspectives Supplement, providing readers the opportunity to compare and contrast PT approaches and models, within the context of their prospective application to an actual-use situation. This introduction to this collection of papers on predictive toxicology summarizes the predictions made and the final results obtained for the 44 chemical carcinogenesis bioassays of the first PTE experiment (PTE-1) and presents information that identifies the 30 chemical carcinogenesis bioassays of PTE-2, along with a table of prediction sets that have been published to date. It also provides background about the origin and goals of the PTE project, outlines the special challenge associated with estimating the true error of models that aspire to predict open-system behavior, and summarizes what has been learned to date.

Animals↗
PubMed1998

Site-specific data confirm arsenic exposure predicted by the U.S. Environmental Protection Agency.

The EPA uses an exposure assessment model to estimate daily intake to chemicals of potential concern. At the Anaconda Superfund site in Montana, the EPA exposure assessment model was used to predict total and speciated urinary arsenic concentrations. Predicted concentrations were then compared to concentrations measured in children living near the site. When site-specific information on concentrations of arsenic in soil, interior dust, and diet, site-specific ingestion rates, and arsenic absorption rates were used, measured and predicted urinary arsenic concentrations were in reasonable agreement. The central tendency exposure assessment model successfully described the measured urinary arsenic concentration for the majority of children at the site. The reasonable maximum exposure assessment model successfully identified the uppermost exposed population. While the agreement between measured and predicted urinary arsenic is good, it is not exact. The variables that were identified which influenced agreement included soil and dust sample collection methodology, daily urinary volume, soil ingestion rate, and the ability to define the exposure unit. The concentration of arsenic in food affected agreement between measured and predicted total urinary arsenic, but was not considered when comparing measured and predicted speciated urinary arsenic. Speciated urinary arsenic is the recommended biomarker for recent inorganic arsenic exposure. By using site-specific data in the exposure assessment model, predicted risks from exposure to arsenic were less than predicted risks would have been if the EPA's default values had been used in the exposure assessment model. This difference resulted in reduced magnitude and cost of remediation while still protecting human health.

Algorithms↗
PubMed2001

Predicting exercise stage transitions over two consecutive 6-month periods: a test of the theory of planned behaviour in a population-based sample.

OBJECTIVES: To predict exercise stage transitions over two consecutive 6-month periods using the theory of planned behaviour (TPB). It was hypothesized that different social cognitive constructs would predict different stage transitions. DESIGN: Prospective and longitudinal in order to predict multiple stage transitions over time. Assessments were made at baseline, 6 months and 1 year. METHOD: Participants were a randomly selected population-based sample of 683 adults who completed two telephone interviews (baseline and 6 months) that assessed exercise stage, intention, perceived behavioural control, attitude, subjective norm, and social support, and a mailed survey (1 year) that assessed exercise stage. RESULTS: Progression from pre-contemplation was predicted by intention, attitude and subjective norm; progression/regression from contemplation was predicted by intention, perceived behavioural control, attitude, and social support; progression/regression from preparation was predicted by intention and attitude; and regression from action/maintenance was predicted by intention, attitude and social support. CONCLUSIONS: Different social cognitive constructs predicted different stage transitions, which indicates that exercise behaviour change may be represented by a series of stage transitions. Moreover, the TPB may be a useful model for highlighting the key social cognitive constructs that are important for exercise stage transitions.

Journal Article↗
PubMed2002

Predictive genetic testing for conditions that present in childhood.

There is a general consensus in the medical and medical ethics communities against predictive genetic testing of children for late onset conditions, but minimal consideration is given to predictive testing of asymptomatic children for disorders that present later in childhood when presymptomatic treatment cannot influence the course of the disease. In this paper, I examine the question of whether it is ethical to perform predictive testing and screening of newborns and young children for conditions that present later in childhood. I consider the risks and benefits of (1) predictive testing of children from high-risk families; (2) predictive population screening for conditions that are untreatable; and (3) predictive population screening for conditions in which the efficacy of presymptomatic treatment is equivocal. I conclude in favor of parental discretion for predictive genetic testing, but against state-sponsored predictive screening for conditions that do not fulfill public health screening criteria.

Age of Onset↗
PubMed2004

Predicting response to omalizumab, an anti-IgE antibody, in patients with allergic asthma.

STUDY OBJECTIVE: To determine baseline characteristics predictive of response to omalizumab, an anti-IgE antibody, in patients with allergic asthma. DESIGN: Pooled analysis of two multicenter, double-blind, randomized, placebo-controlled phase III studies with omalizumab. PATIENTS: One thousand seventy allergic asthma patients symptomatic despite moderate-to-high doses (mean, 725 micro g/d) of inhaled beclomethasone dipropionate (BDP). INTERVENTIONS: Omalizumab (n = 542) or placebo (n = 528) were administered at a 4-weekly subcutaneous dose of at least 0.016 mg/kg/IgE (IU/mL) for 16 weeks in addition to stable BDP therapy. MEASUREMENTS AND RESULTS: Univariate logistic regression was performed to explore baseline variables predictive of best response. Various aspects of response (reduced symptom scores, reduced usage of rescue medication, improved lung function, improved quality of life [QoL]) were explored as well as a composite definition of response (response in at least one of these four aspects with no asthma exacerbation during 16 weeks of treatment). Time to onset of response as well as the ability to predict eventual response were also determined for the composite definition of response. A consistent pattern of predictive covariates was seen over all definitions of response (except for QoL). For the composite definition, a history of emergency asthma treatment in the past year was the factor most predictive (p = 0.015) of best response on active treatment (response rate for those with such history was 67% for omalizumab and 42% for placebo; for those without a history the response rates were 63% and 54%, respectively). Another factor predictive of best response on active treatment was high BDP dose (p = 0.037; response rate for those treated with >or= 800 micro g/d was 65% for omalizumab and 40% for placebo; for those treated with < 800 micro g/d, the response rates were 63% and 55%, respectively). A low FEV(1) was also predictive (p = 0.072; response rates for those with FEV(1) or= 65% predicted, the response rates were 67% and 53%, respectively). Seventy-six percent of patients had at least one of these factors. This subgroup showed odds of being a responder (composite definition) 2.25 times higher (95% confidence interval, 1.68 to 3.01) than placebo. Some 38% of patients treated with omalizumab showed a response (composite definition) at the first evaluation time point at 4 weeks, increasing to 64% at week 16 (vs 48% for placebo; p < 0.001). Among omalizumab responders at 16 weeks, only 61% had responded at 4 weeks whereas 87% had responded at 12 weeks. CONCLUSIONS: Patients who benefit most when omalizumab is administered as add-on therapy are those receiving high doses of BDP, those with a history of frequent emergency asthma treatment, and those with poor lung function. Patients should be treated with omalizumab for a minimum duration of 12 weeks.

Adolescent↗
PubMed2005

Prediction of successful cardioversion and maintenance of sinus rhythm in patients with lone atrial fibrillation.

OBJECTIVE: We aimed to prospectively investigate the predictive value of echocardiographic parameters for the prediction of successful cardioversion and long-term sinus rhythm (SR) maintenance in patients who have experienced a lone episode of atrial fibrillation (AF). MEASUREMENTS AND RESULTS: Clinical and echocardiographic data, including mean left atrial appendage (LAA) peak flow velocity and mitral annulus motion, were analyzed in 78 consecutive patients (mean [+/- SD] age, 59.3 +/- 9.3 years) with AF lasting > 48 h and < 6 months. Sixty-one patients (78%) underwent successful external electrical cardioversion, while the remaining remained in AF. At the 1-year follow-up, of the 61 patients who had successfully been converted to SR, 24 (39.3%) remained in SR. For predicting the success of the cardioversion, we used a model consisting of two variables. LAA flow velocity (> 20 cm/s) and left ventricular (LV) fractional shortening (> 30%) appear to be quite strong, yielding 83.3% correct results. For predicting the maintenance of SR, we used a model consisting of two variables. The absence of the early systolic abnormal mitral annulus motion and LAA flow velocity (> 20 cm/s) appears to be quite strong, yielding 84.6% correct results. LAA flow velocity only marginally enters the model, and, if removed, little predictive value is lost (dropping to 83.3%). Removing the early systolic abnormal mitral annulus motion variable, the prediction value drops significantly to 70.5%. CONCLUSION: LAA flow velocity combined with LV fractional shortening can predict the success of the conversion of AF to SR. Additionally, LAA flow velocity, combined with the analysis of mitral annulus motion before cardioversion, can predict the long-term maintenance of SR.

Aged↗
PubMed2005

Role of quantitative CT in predicting hypoxemia and complications after lung lobectomy for cancer, with special reference to area of emphysema.

STUDY OBJECTIVES: To determine the ability of quantitative CT, with special reference to area of emphysema, to predict early postoperative oxygenation capacity and outcome after lung lobectomy for cancer. METHODS: Sixty-two consecutive patients scheduled to undergo lung lobectomy for cancer were enrolled in this study. The area of emphysema (< - 910 Hounsfield units) was measured on a three-dimensional CT lung model. Arterial oxygen saturation (Sao(2)) was calculated from Pao(2) measured 1 day before and 1 day after surgery with patients at rest breathing room air. A patient was considered to have recovered at the completion of a standardized management regimen. RESULTS: Postoperative Sao(2) (postSao(2)) was predicted by the baseline value and the area of emphysema with the use of a regression equation. Ten of the 62 patients (16%) had postoperative cardiopulmonary complications (CPCs). The median time to postoperative recovery was 3 days (range, 1 to 17 days). Predicted postSao(2) and predicted postoperative FEV(1) were shown to be significant independent predictors of postoperative CPCs as well as postoperative recovery time. CONCLUSION: Determining the area of emphysema by quantitative CT is useful in predicting early postoperative oxygenation capacity. Predicted oxygenation capacity and predicted ventilatory capacity independently affect perioperative outcomes. Therefore, using quantitative CT in combination with spirometry may improve risk prediction in patients undergoing lung lobectomy for cancer. However, the role of quantitative CT in grading nonemphysematous lung diseases, such as interstitial lung diseases, must be investigated.

Aged↗
PubMed2002

Prediction of clearance in humans from in vitro human liver microsomes and allometric scaling. A comparative study of the two approaches.

The objective of this study was to evaluate whether the predicted clearance of a drug in humans from in vitro human liver microsomes was comparable with the predicted clearance in humans obtained by allometric scaling. Sixteen drugs were randomly selected from the literature and their hepatic clearances were predicted using human liver microsomes. For allometric scaling at least three animal species were used and three methods were utilized to generate allometric equations to predict the clearance in humans: (i) clearance vs body weight (simple allometry); (ii) product of the clearance and maximum life-span potential (MLP) vs body weight; and (iii) the product of clearance and brain weight vs body weight. The choice of one of the methods was based on the 'rule of exponents' as described by Mahmood and Balian /2,3/. The results of this study indicated that the use of human liver microsomes to predict hepatic clearance in humans may not provide reliable predictions. On the other hand, the prediction of clearance in humans using allometric scaling combined with the 'rule of exponents' can provide comparatively better prediction of clearance in humans.

Animals↗
PubMed2002

A statistical method for predicting automobile driving posture.

A new model for predicting automobile driving posture is presented. The model, based on data from a study of 68 men and women in 18 vehicle package and seat conditions, is designed for use in posturing the human figure models that are increasingly used for vehicle interior design. The model uses a series of independent regression models, coupled with data-guided inverse kinematics, to fit a whole-body linkage. An important characteristic of the new model is that it places greatest importance on prediction accuracy for the body locations that are most important for vehicle interior design: eye location and hip location. The model predictions were compared with the driving postures of 120 men and women in five vehicles. Errors in mean eye location predictions in the vehicles were typically less than 10 mm. Prediction errors were largely independent of anthropometric variables and vehicle layout. Although the average posture of a group of people can be predicted accurately, individuals' postures cannot be predicted precisely because of interindividual posture variance that is unrelated to key anthropometric variables. The posture prediction models developed in this research can be applied to posturing computer-rendered human models to improve the accuracy of ergonomic assessments of vehicle interiors.

Adult↗
PubMed2006

Estimating the combined toxicity by two-step prediction model on the complicated chemical mixtures from wastewater treatment plant effluents.

The toxicities of chemical mixtures containing 10 compounds, detected in wastewater treatment plant (WWTP) effluents, were investigated using Daphnia magna in a two-step prediction (TSP) model. The 10 chemicals determined by gas chromatography/ mass spectrometry in WWTP effluents included three groups: Three acetylcholinesterase inhibitors, six narcosis inhibitors, and one seedling root inhibitor. In the first step, a concentration addition (CA) model was used to predict the mixture toxicities for the three component groups with similar modes of action; in the second step, an independent action (IA) model was used for the newly developed concentration-response curves from the three CA predictions. The CA predictions did not show a statistically significant difference from the observed results with respect to the three groups of chemicals, whereas the IA model did not conform to the experimental results. Therefore, the concentration-response curves obtained from the mixture toxicity tests in each group was considered as a single curve and applied in the next step of the mixture toxicity prediction. However, the observed toxicity of the 10-chemical mixture showed large differences from the results of the IA and CA model predictions, whereas the TSP model predicted the toxicity well and with statistical significance (p = 0.0501, n = 17). This suggests that the TSP model would provide a valid prediction for a randomly selected chemical mixture having various modes of action if the concentration-response function for an individual component is obtained.

Animals↗
PubMed1990

Prediction of clinical diabetic nephropathy in IDDM patients. Alternatives to microalbuminuria?

This perspective deals with prediction of overt diabetic nephropathy in patients with insulin-dependent diabetes mellitus (IDDM). The role of elevated urinary albumin excretion rate (microalbuminuria) in predicting diabetic nephropathy has been emphasized by new follow-up studies. Development of severe kidney impairment was seen in a large percentage of patients with microalbuminuria, but with more intensive care for diabetic patients, this percentage may be falling. Herein, I analyzed alternatives to microalbuminuria in predicting kidney disease in diabetes. 1) Parental predisposition to hypertension is not seen in all studies and therefore may not be a decisive factor, and it cannot be used in prediction of nephropathy. 2) Prediabetic blood pressure may predict nephropathy in certain non-insulin-dependent diabetic patients, but elevated blood pressure seems to develop after early microalbuminuria and is likely to be an aggravating factor in established microalbuminuria in IDDM patients. 3) At the clinical diagnosis of IDDM, diabetic nephropathy cannot be predicted. 4) Glycemic control is poor in normoalbuminuric patients with later development of microalbuminuria, and multiple glycosylated hemoglobin measurements are therefore important. 5) In diabetes, glomerular hyperfiltration is associated with late nephropathy, but it alone cannot be the decisive factor, because hyperfiltration in nondiabetic individuals does not produce kidney disease, according to new long-term follow-up studies. 6) Studies of glomerular structure and ultrastructure have not yet documented predictive values for overt nephropathy, but further studies are in progress. 7) Isolated blood pressure elevation without microabuminuria (probably representing essential hypertension in diabetes) has not been predictive. 8) It is clear that elevation of serum creatinine is a very late and insensitive parameter, occurring only with pronounced proteinuria.(ABSTRACT TRUNCATED AT 250 WORDS)

Albuminuria↗
PubMed2005

Prediction of serum ionized calcium concentration by use of serum total calcium concentration in dogs.

OBJECTIVE: To determine whether total serum calcium (tCa) or adjusted tCa concentrations accurately predict ionized calcium (iCa) status in dogs. SAMPLE POPULATION: 1,633 canine serum samples. PROCEDURE: The tCa concentration was adjusted for total protein (TP) or albumin concentration by use of published equations. Correlations between iCa and tCa or adjusted tCa, tCa and TP, and tCa and albumin were calculated. Diagnostic discordance between tCa or adjusted tCa and iCa was determined. Diagnostic discordance in predicting iCa was also determined for 490 dogs with chronic renal failure (CRF). Sensitivity, specificity, positive and negative predictive values, and positive and negative diagnostic likelihood ratios were calculated for tCa, tCa adjusted forTP, and tCa adjusted for albumin. RESULTS: Diagnostic discordance was 27% when tCa concentration was used to predict iCa status. Use of adjusted tCa increased diagnostic discordance to approximately 37% for all dogs and 55% for dogs with CRF. Positive predictive value and positive diagnostic likelihood ratios were poor when tCa concentration was used to predict iCa status. The tCa concentration overestimated normocalcemia and underestimated hypocalcemia. Adjusted tCa overestimated hypercalcemia and underestimated hypocalcemia. CONCLUSIONS AND CLINICAL RELEVANCE: Adjusted tCa or tCa concentrations are unacceptable for predicting iCa status in dogs. Use of adjustment equations is not recommended. Direct measurement of iCa concentration is necessary for accurate assessment of calcium status. Use of tCa or adjusted tCa concentrations to predict iCa status in dogs could cause serious mistakes in diagnosis and case management, especially in dogs with CRF.

Animals↗
PubMed2005

Differences in saccadic latency and express saccades between skilled and novice ball players in tracking predictable and unpredictable targets at two visual angles.

The purpose of the study was to investigate saccadic latency and percentage of express saccades involved in predictable tasks between skilled and novice ball players. Participants performed four different tasks, including time and direction unpredictable task, time predictable task, direction predictable task, and time and direction predictable task at the visual angles of 10 and 20 degrees. Skilled ball players had shorter mean saccadic latency than novice players on direction and time and direction predictable tasks. The percentage of express saccades of skilled ball players was higher than that of novice players on the latter. Saccadic latency was shorter in the 10 degrees condition in time and direction unpredictable task and time predictable task than for 20 degrees. These results suggested that predictive ability might be one of the general characters distinguishing skilled ball athletes from novices in visuomotor performance. The prediction might reduce the mean difference in the saccadic latency at various visual angles.

Adult↗
PubMed2001

Predicting physical therapy visits needed to achieve minimal functional goals after arthroscopic knee surgery.

STUDY DESIGN: Retrospective, cross-sectional regression modeling. OBJECTIVE: To predict physical therapy visits following arthroscopic knee surgery. BACKGROUND: The number of physical therapy visits required to achieve a set of specific minimal-level goals (full knee extension, straight leg raise, normalized gait pattern, bicycle pedaling, and independent home exercises) that are related to decreased complication rates has not previously been modeled. METHODS AND MEASURES: A multiple regression model to predict postoperative physical therapy visits was developed using subject demographics and 2 simple clinical measures, degree of straight leg raise lag and total range of motion. All data were collected from 148 patient charts. Model validity was examined by the predicted residual sum of squares technique and a second independent sample of 157 charts. RESULTS: Diagnosis group, surgery group, and range of motion were the significant variables predicting visits in the final model (R2 = 0.384). Results of model validation analyses using predicted residual sum of squares technique (R2 = 0.346) and the second set of data (R2 = 0.282) were satisfactory. Analysis of residuals (difference of observed and predicted visits) showed prediction of the number of physical therapy visits within 3 visits for approximately 75% of the cases in both sets of data. CONCLUSIONS: Using the model to predict physical therapy visits following arthroscopic knee surgery was more accurate than using diagnosis alone, except for lateral retinacular release. This study demonstrates how regression models could be used to explain variance in physical therapy visits for a given set of minimal functional goals.

Activities of Daily Living↗
PubMed1992

A computer model to predict empty body weight in cattle from diet and animal characteristics.

A computer model was developed to predict empty BW in cattle as a function of diet (forage NDF, physical form of forage [hay vs silage and pasture], proportion of dietary concentrates) and animal (full BW) characteristics. The model was empty BW = full BW * (1 - GFILL), where GFILL is gut fill expressed as a fraction of full BW. An equation obtained from published data (GFILL = .05354 + .329 * NDF) was used to provide a base prediction of GFILL from the fraction of NDF in the forage. Predicted GFILL was then corrected for full BW, physical form of forage, and fraction of concentrates using multiplicative factors obtained from published data. The model was evaluated with data from 11 published experiments. Several breeds of cattle, a wide range of forage types, and diets with 0 to 93% concentrates were represented in these data. Observed values for empty BW were compared to model-predicted values and to values predicted by systems published by the Agricultural Research Council (ARC) and National Research Council (NRC). Sums of squared deviations of predicted values from observed (n = 64) were 3,074, 37,327, and 25,920 for the model, ARC, and NRC systems, respectively. After fitting predicted empty BW values to observed values, proportion of concentrates and forage NDF accounted for a significant (P less than .01) amount of the residual variation with the ARC and NRC systems, but not for the model. This finding suggests that the model will predict empty BW more accurately than the ARC and NRC systems with diets similar to those used in the evaluation.

Animal Feed↗
PubMed1995

Prediction of carcass and empty body composition of steers by 40K emission detection.

Although originally used for prediction of whole body composition (WBC), use of 40K emission detection was later suggested for determination of empty body composition (EBC), Therefore, the present study was conducted to validate existing equations developed to predict WBC and to develop more useful equations to predict EBC or carcass composition (CC) of beef steers. Fourteen crossbred steers were detected for 40K emissions and slaughtered and their chemical composition determined from chemical analyses and total body K determined from 40K emissions. the existing equation for percentage whole body lipid had a slope of .93 and an intercept of -1.62%, indicating a close approximation of percentage of whole body lipid. Percentage of whole body protein was poorly estimated by existing equations. Equations developed for prediction of EBC relied on both BW and predicted K. Coefficients of variation for prediction of empty water or protein were within 5% and those for prediction of empty body lipid were approximately 15%. These results demonstrate that use of predicted K from 40K emission detection enhances the determination of EBC and CC.

Animals↗