engleski

Fatty acid composition of subcutaneous adipose tissue of brown bear (Ursus arctos) in Croatia

Accurate information on foraging is essential for understanding, management and conservation of wildlife populations. In Croatia, research of the brown bear nutritional ecology was based mainly on faeces analysis which can only show the composition of the relatively recent meal. In contrast, fatty acids (FA) indicate feeding habits of individuals over an extended period of time, thus providing more reliable information about how individuals meet their energy needs. The study was conducted on 91 specimens of brown bear (25 females and 66 males) harvested in the hunting season. After thawing, homogenization and lipid extraction of subcutaneous adipose tissue, the FA composition was determined by gas chromatography with regard to gender, sampling season and sampling location. Lipids isolated from the subcutaneous adipose tissues of brown bear were dominated by monounsaturated fatty acids (MUFA ; females 45.61%, males 41.09 %), the second most represented were saturated FAs (SFA ; females 26.18%, males 37.97%) and polyunsaturated fatty acids (PUFA ; females 24.69 %, males 20.94%) were the least represented. In males the percentages of C16:0, C16:1, C17:0, SFA and MUFA were significantly higher in spring than in autumn. Also, in males the percentages of C18:2 and PUFA were significantly lower in spring compared to autumn. In autumn the percentages of C16:1 and MUFA were lower and the percentages of C15:0 and SFA were higher in males compared to females. In Primorsko- goranska county, in males percentages of C8:0, C14:0, C18:3 and C20:1 were significantly higher and the percentage of C20:0 was significantly lower compared to Ličko-senjska county. In Primorje-Gorski Kotar County percentages of C15:0, C17:0 and SFA were higher in males compared to females. Based on the results, it can be concluded that the presence of fatty acids, for both females and males, differs according to the season and is dependent on sampling location. Higher percentage of PUFA in the subcutaneous adipose tissue in autumn indicates the importance of these fatty acids for brown bear wintering.

brown bear; fatty acid composition; subcutaneous adipose tissue

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