Determination of Body Composition of Steers by 40K

Abstract

The body composition of 56 steers ranging in weight from 183 to 574 kg was estimated from ⁴⁰K which was measured in a Whole Body Counter. After monitoring in the Counter for ⁴⁰K, the animals were slaughtered by normal procedures, and analyses of all tissues were made for moisture, ether extract, nitrogen, K, ash and gross energy. Independent variables, live and carcass weight, live and carcass ⁴⁰K and carcass specific gravity were used to predict the dependent variables, carcass or empty body ether extract, nitrogen, water and gross energy. Significant relationships (P<.01) existed between all independent and dependent variables. The R² values between ⁴⁰K and nitrogen, ether extract, water and gross energy were lower than when specific gravity was compared to these dependent variables. However, R² values obtained when ⁴⁰K and live weight were used to predict nitrogen, ether extract, water and gross energy of the carcass were .87, .87, .84 and .84, respectively. The R² values obtained when ⁴⁰K and live weight were used to predict fat-free body and fat-free carcass weight were .97 and .96, respectively. Copyright © 1976. American Society of Animal Science . Copyright 1976 by American Society of Animal Science.