engleski

Blood fatty acid composition in free-ranging and captive European brown bears

The composition and incorporation of fatty acids (FA) in blood cells is the resultant of food intake, metabolism and peripheral utilization. Essential polyunsaturated FA (PUFA), linoleic (LA, C18:2n-6) and linolenic (LNA, C18:3n-3) cannot be synthesized by most mammals therefore have to be ingested. They serve multiple functions, and the balance between dietary n-3 and n- 6 PUFA strongly affects cellular functions. Eicosapentaenoic (EPA, 20:5n-3) docosahexaenoic (DHA, C22:6n-3) and arachidonic acid (AA, C20:4n- 6) are known as "conditionally essential". The objective of the study was to analyse the FA composition of erythrocytes and whole blood in free-ranging (Dinara-Pindos and Carpathian populations) and captive brown bears. The study was conducted on 29 animals (16, Croatia ; 13, Poland). Total lipids were extracted and the composition of FA methyl esters was determined by gas chromatography. Lipids isolated from the blood of free-ranging Croatian and Polish bears were dominated by saturated FA (SFA, 65.7±14.3% vs. 45.0±4.3% ; p<0.05). Second in the representation in free-ranging Croatian bears (N=13) were PUFA (20.6±12.3% vs. 23.06±4.36% in Poland ; p>0.05), while in freeranging Polish bears (N=10) those were monounsaturated FA (MUFA, 31.9±3.1% vs. 13.6±6.5% in Croatia ; p<0.05). Lipids isolated from blood of captive bears in both countries (Croatia vs. Poland) were composed as follows: SFA (66.2±6.2% vs. 40.8±2.6% ; p<0.05), PUFA (16.9±2.2 vs. 31.8±1.3% ; p<0.05), MUFA (16.9±7.3 vs. 27.3±3.9% ; p>0.05). Significantly higher percentages of LNA (2.1±1.1 vs. 0.3±0.1%), AA (8.5±8.1 vs. 0.3±0.2%), DHA (1.8±0.9 vs. 0.7±0.5%) and AA/EPA ratio (0.9±0.6 vs. 0.04±0.02) were found in free-ranging Croatian compared to free-ranging Polish bears. Significantly higher LA (14.98±0.78 vs. 4.39±0.99%), EPA/DHA ratio (9.92±2.15 vs. 2.22±0.02%) and n-3 PUFA family (15.41±1.89 vs. 10.18±2.08%) were found in captive bears from Poland compared to those in Croatia. The FA representation, especially of essential FA, can provide an important health assessment, while variation in the diet FA composition may have an influence on some aspects of animal performance.

blood, fatty acid, Ursus arctos

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