A Comparison of Ultrasonic Estimates of Rib-Eye Area and Fat Thickness in Cattle

Abstract
A comparison of estimates of rib-eye area and fat thickness on 27 cattle by two similar ultrasonic instruments independently operated by two individuals is reported. Highly significant correlations between ultrasonic live animal estimates and carcass rib-eye area and fat thickness suggest that ultrasonic estimates of these traits are reliable indicators of the corresponding carcass measurements. When the effect of sex was removed, which also included some adjustment for weight differences, the correlations between these variables were highly significant, but were lower than the simple correlations. A significant difference existed between the two operators in interpretation of the rib-eye area on sonographs from the same ultrasonic unit. Correlations for four ultrasonic rib-eye area and fat thickness estimates with carcass rib-eye area and fat thickness measurements did not differ from each other, suggesting that ultrasonic methods for estimating carcass rib-eye area and fat thickness are reasonably repeatable. Copyright © 1966. American Society of Animal Science . Copyright 1966 by American Society of Animal Science