The composition and energy content of empty body-weight change in mature cattle

ABSTRACT Body-composition data from 73 non-pregnant, non-lactating cows of five genotypes were used to calculate the composition of empty body-weight change in mature cattle. The composition of empty body-weight change was shown to be dependent on empty body weight, containing more fat and less water, protein and ash at higher empty body weights. There were no differences between the genotypes. Between 300 and 600 kg empty body weight the protein concentration in empty body-weight change ranged from 125 to 40 g/kg, whilst application of standard energy values for fat and protein gave equivalent figures for body energy of 22·5 to 32·7 MJ/kg.