Realtime Ultrasound and Body Composition

Predicting Percentage of Intramuscular Fat Using Two Types of Real-Time Ultrasound Equipment

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Abstract

A total of 500 steers were used to develop models for prediction of percentage of intramuscular fat (PIMF) in live beef cattle. Prior to slaughter, steers were scanned across the 11th and 13th ribs using Aloka 500V and PIE scanner 200 machines. After slaughter, a cross-sectional slice of the longissimus dorsi muscle from the 12th rib facing was used for chemical extraction to determine carcass intramuscular fat measures (CIMF). Texture analysis software was used by two interpreters to define image parameters, which included Fourier, gradient, histogram, and co-occurrence parameters. A total of four prediction models were developed for each machine. These included, models developed without transformation of CIMF (model-I), models based on logarithmic transformation of CIMF (model-II), ridge regression (model-III), and principal components regression (model-IV) models. Model R2 and root mean square error (RMSE) of Aloka models I, II, III and IV were .72, .84%; .72, .86%; .69, .91%; and .71, .86%; respectively. The corresponding R2 and RMSE value of PIE models I, II, III, and IV were .68, .87%; .70, .85%; .64, .94%; and .65, .91%; respectively. All models were validated on an independent data set from 71 feedlot steers. The overall mean bias, standard error of prediction (SEP), and rank correlation coefficient across the four Aloka models were .42%, .84%, and .88, respectively. For PIE models the corresponding values were .67%, .81%, and .91, respectively. Both Aloka and PIE equipment can be used to accurately predict PIMF in live cattle. Further improvement in the accuracy of prediction could be achieved through increasing the development data set and the variation in PIMF of cattle used.

Keywords: ASL R1732

How to Cite:

Hassen, A., Wilson, D., Amin, V., Rouse, G. & Hays, C., (2001) “Predicting Percentage of Intramuscular Fat Using Two Types of Real-Time Ultrasound Equipment”, Iowa State University Animal Industry Report 1(1).