689 Journal of Animal and Feed Sciences, 13, Suppl. 1, 2004, 689-692 Kangaroo adipose tissue has higher concentrations of cis 9, trans 11-conjugated linoleic acid than lamb adipose tissue * C.F. Engelke 1,2 , B.D. Siebert 3 , K. Gregg 4 , A-D.G. Wright 2 and P.E. Vercoe 1,5 1 Animal Biology, University of Western Australia 2 CSIRO Livestock Industries, Centre for Environmental and Life Sciences Floreat Park, Western Australia 3 Department of Animal Science, University of Adelaide, South Australia 4 Centre for High-Throughput Agricultural Genetic Analysis, Murdoch University Western Australia ABSTRACT Ruminant tissues and products contain conjugated linoleic acids (CLA) due to biohydrogenation in the rumen. We hypothesize that kangaroos would have higher concentrations of CLA compared to lambs due to incomplete biohydrogenation of fatty acids in the kangaroo foregut. Fatty acid composition of adipose tissue (including cis 9, trans 11 CLA) from lambs and kangaroos were significantly different. The concentrations of CLA and its precursor trans vaccenic acid (TVA) in the adipose tissue of kangaroos were approximately four and five times that of lambs. Kangaroo fat was significantly less saturated and had a lower melting point. KEY WORDS: CLA, lamb, kangaroo, fatty acids, desaturase INTRODUCTION Conjugated linoleic acids (CLA) represent a series of isomers derived from octadecadienoic acid found in ruminant fat as a result of biohydrogenation in the foregut. In addition the animal synthesises CLA endogenously in mammary and adipose tissue. CLA has been found to have anticarcinogenic properties in vivo and to reduce the incidence of tumours in animal models (Bauman et al., 2000). The fatty acid profiles of ruminant meats are more saturated than other species, * Supported by the Rural Industries Research and Development Corporation. 5 Corresponding author: e-mail: pvercoe@agric.uwa.edu.au