3. Results
3.1. Laboratory experiments—tissue distribution of caprylic acid
Caprylic acid was immeasurable in tested tissues of both groups at the last sampling point (24 h). Analysis of caprylic acid in serum, gills and skin (Fig. 1) revealed also undetected levels at 0.5, 1 and 2 h post feeding in fish fed the low dosing diet. Further, with the exception of skin at 8 h sampling, significantly lower caprylic acid concentrations were measured in the low compared to double dosing group. In fish fed the high dosing diet, caprylic acid was detected already at 0.5 h post feeding in serum, showing an upward trend until 4 h post feeding and then concentration reached a plateau until the 10 h time point. In gills, the substance appeared almost as early as in circulation with the highest, among all tested tissues, level reached at 6 h, while it was rapidly decreased at the following samplings. A delayed appearance of caprylic acid was evident in skin tissues with the first measurement appearing 4 h post administration. A decreasing pattern was thereafter observed except for the 10 h sampling.