Accumulation of dietary fish fatty acids in the body fat reserves of some carnivorous fur-bearing animals

Abstract

Body fat composition of the mink (Mustela vison), polecat (Mustela putorius), and the raccoon dog (Nyctereutes procyonoides) was studied. The animals were fed a wet diet, supplemented with 5 % lard (LA) or fish oil (FO) for 5-6 months. At pelting, five animals per dietary group were sampled. Dietary levels of cetoleic (C22:1ω11), eicosapentaenoic (EPA, C20:5ω3), and docosahexaenoic (DHA, C22:6ω3) acids were 0.4, 0.3, and 0.5% in the fat of the LA diet, and 7.6, 4.2 and 4.3% in the FO diet, respectively. In the FO diet, EPA and DHA accumulated especially in the liver and heart, while cetoleic acid showed the highest affinity to the heart muscle and subcutaneous fat. The highest levels of EPA were found in raccoon dogs and polecats fed the FO diet. The mean EPA levels ranged from 6.7-9.3% in the liver fat and 7.2-8.0% in the heart muscle fat. In the mink, the corresponding values were 2.7% and 3.9%, respectively. DHA levels were the highest in the liver fat of the polecats, being 18.5% in the FO diet. In addition, the liver in raccoon dogs fed the FO diet (13.8%) differed significantly from themink (9.4%). The differences in the accumulation of these long-chained marine fatty acids were apparently caused by species differences in the efficiency of their peroxisomal β-oxidation.

Chemical and carbon isotopic composition of fatty acids in adipose tissue as indicators of dietary history in wild arctic foxes (A lopex lagopus) on Svalbard

“…In this paper, we measure the carbon isotope compositions of individual fatty acids in adipose tissue from arctic foxes collected from four different localities on Svalbard, to examine whether such data can be used to distinguish the origin of each fatty acid. Small carnivores seem to retain fatty acids derived from fish lipids particularly efficiently (Rouvinen et al, 1992) so arctic foxes seemed as good a species as any other wild mammal in which to investigate the feasibility of assessing the contributions of the marine and terrestrial food chains to the diet from the chemical and isotopic composition of the storage lipids.…”

Using fatty acids to study marine mammal foraging: The evidence from an extensive and growing literature

“…2008), terrestrial and aquatic carnivores ( e.g ., Reidinger et al . 1985, Rouvinen and Kiiskinen 1989, Rouvinen et al . 1992, Iverson et al .…”

“…An extensive scientific literature exists that demonstrates and quantifies the relationship between a consumer's FA stores and the FA composition of its diet. Marine mammals have the same basic metabolic pathways as other higher vertebrates and the predictable incorporation of ingested FAs into adipose tissue and blubber has been experimentally demonstrated through controlled feeding studies of seals (Kirsch et al 2000Budge et al 2004, Cooper 2004, Tollit et al 2006, Cooper et al 2006, Nordstrom et al 2008, terrestrial and aquatic carnivores (e.g., Reidinger et al 1985, Rouvinen and Kiiskinen 1989, Rouvinen et al 1992, Cooper et al 2006, and seabirds , as well as fish and invertebrates (reviewed in Dalsgaard et al 2003). In addition to these controlled experiments, many other studies have analyzed the FA composition of the blubber of free-ranging marine mammals and their prey "together" (note that some studies report predator and prey data in separate papers although they were collected "together," that is, spatially and temporally "from the same waters," which is clearly explained in the papers themselves; e.g., Ackman and Eaton 1966, Iverson et al 1995Iverson et al , 1997Iverson et al , 2004Dahl et al 2000, Bradshaw et al 2003, Cooper 2004, Falk-Petersen et al 2004, Beck et al 2007aBudge et al 2008, Tucker et al 2008).…”

Stable isotopes in adipose tissue fatty acids as indicators of diet in arctic foxes (Alopex lagopus)

“…Small carnivores seem to retain fatty acids derived from fish oils particularly efficiently (Rouvinen et al 1993).…”