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

Authors

• Kirsti Rouvinen Agricultural Research Centre of Finland, Fur Farming Research Station, SF-69100 Kannus, Finland
• Jaakko Mäkelä Finnish Fur Breeders’ Association,, P.0.Box 5, SF-01601 Vantaa, Finland
• Tuomo Kiiskinen Agricultural Research Centre of Finland, Institute of Animal Production, SF-31600 Jokioinen, Finland
• Seppo Nummela Agricultural Research Centre of Finland, Central Laboratory, SF-31600 Jokioinen, Finland

DOI: https://doi.org/10.23986/afsci.72461

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.