Proportions of polyunsaturated fatty acid (PUFA) in ruminant tissues are generally low as dietary PUFA including linoleic acid (LA) and α-linolenic acid (ALA) undergo biohydrogenation to stearic acid in the rumen. Conjugated linoleic acid (CLA) is formed during biohydrogenation as an intermediate metabolite. Feeding PUFA-rich sources can enhance deposition in the tissues of ruminants (Bolte et al, 2002), but the degree of lipid hydrogenation may depend on the source form and the ruminant species (Rowell-Schäffer et al, 2001). Bolte et al, (2002) showed that oilseed-fed sheep had higher PUFA proportions in their tissues than sheep fed a beet pulp-based diet but Rowell-Schäffer et al (2001) found in deer tissues higher PUFA proportions than in those of sheep. Possible effects of the form of the lipid source and the ruminant species on the fatty acids deposited were tested.