The first insights on trans-galactooligosaccharide effects on fatty acids profile and microstructure of muscle in common carp

The aim of the study was to determine the effects of prebiotic GOS on muscle histomorphometry and the total lipid, total cholesterol content and fatty acids profile in the meat of common carp. The 60-day-long experiment was performed on one-year-old fish. Three diets were used in the experiment: control diet 1 (C) with no microbiota affecting feed additives, diet 2 (B1) with 1 % of GOS, and diet 3 (B2) with 2 % of GOS. At the end of the trial, 16 individuals from each treatment group were used for the analyses. Fish meat from the B1 group had significantly higher lipid content compared to B2, but neither B1 nor B2 groups were different from the control group. The percentages of SFA, MUFA, PUFA, indexes n-3/n-6, PUFA/SFA, AI and TI, and total cholesterol content were not affected, in contrast to C14:0, C16:1 n-7, C18:0, C18:2 n-6, C20:4 n-6, and total n-6 FA. GOS significantly increased the percentage of normal fibres, while the lower number of fibre atrophy and splitting were observed. The results confirm that diet supplemented with 2 % GOS may be recommended as feed additive in carp nutrition due to positive effects on some fatty acids profiles and muscle microstructure.