[Evaluation of fatty acid levels and selected bioelements in femoral bones of chicks depending on age].

The study was done in Starbro chicks aged 1 to 50 days. Two chicks were collected every day and the femoral bones were removed. Altogether, 200 bones were studied. The material was divided into 5 age groups (I to V). Compact and spongy bone, bone marrow and articular cartilage were sampled. Lipids were extracted according to Folch et al. Total lipids were measured spectrophotometrically. Gas chromatography was used to study the content of individual fatty acids. Calcium (Ca), phosphorus (P), magnesium (Mg) and zinc (Zn) levels were determined using atomic absorption spectrometry (Philips PU 9100X), while fluorine content was studied with gas chromatography. As the distribution of the results deviated from normal, non-parametric Kruskal-Wallis and median tests were used. Correlations were studied with Spearman's Rs coefficients. Computations were done with Statistica 5.0 (StatSoft) software and the level of significance was taken as p < 0.05. Statistically significant differences in the fatty acid profile (Tab. 1) and content of elements (Tab. 2) were found. The content of fatty acids, calcium and fluorine correlated with age. Fatty acids with the highest content in bone tissues were C18:1, C16:0, C18:2 and C18:0. The highest content of fatty acids was found in bone marrow and the lowest in articular cartilage. Several correlations were revealed between individual fatty acids and elements (Tab. 3, 4). The following conclusions were drawn: 1) The fatty acid profile in compact and spongy bone, bone marrow and articular cartilage changed according to age of chicks; 2) Content of calcium, phosphorus, magnesium, zinc and fluoride correlated with age; 3) Oleic (C18:1), palmitic (C16:0), linoleic (C18:2), stearic (C18:0) and arachidonic acid (C20:4) accounted for the majority of the fatty acid pool; 4) Correlations in the content of fatty acids and elements were noted between bone structures. Fatty acids appear to play an important role in the metabolism of bone tissues, particularly in mineralization processes.