Tissue turnover in ovine muscles and lipids as recorded by multiple (H, C, O, S) stable isotope ratios

Multiple stable isotope ratios (delta H-2, delta C-13, delta O-18 and delta S-34) were measured in muscle, muscle lipids and lipid fractions collected from 28 lambs, subjected to a diet-switch and raised on two energy allowances (EAs), to determine tissue turnover and diet-tissue fractionation. The diet-muscle fractionations prior to the diet-switch were estimated to be -44.0 parts per thousand, +1.9 parts per thousand and 0 parts per thousand for H, C and S, respectively, while the drinking water was demonstrated to be the main source of muscle 0 and thus delta O-18 variation. The diet-intra-muscular lipid fractionations prior to the diet-switch were estimated to be -172.7 parts per thousand, -1.3 parts per thousand. and -11.5 parts per thousand. for H, C and O, respectively. The C half-lives of muscle were determined to be 75.7 and 91.6 days for animals receiving the high and low EA, respectively. Extracting temporally resolved pre-slaughter dietary information from meat by analysing bulk muscle, muscle lipids and muscle lipid fractions appeared to be not practicable due to possible incomplete turnover of lipids. (C) 2010 Elsevier Ltd. All rights reserved.