4.3. Plasma analysis

Hand-reared capercaillies had a higher uric acid and T4 concentration in plasma (I, Table 3). No differences were found between birds fed natural and control food in work III (Table 6). No effects of tannin were seen in amino acid or nitrogenous compound concentrations (V, Fig. 2). However, birds fed natural food had elevated alanine concentration in plasma in comparison to control or tannin food fed birds (V, Fig. 2).