n-3 enrichment of chicken meat using fish oil: Alternative substitution with rapeseed and linseed oils

Two sequential experiments were conducted to assess the effect of replacing a fish oil diet with vegetable oil diets on broiler chicken performance an d fatty acid (FA) composition and sensory traits of broiler meat. A diet en riched with 8.2% fish oil (FO) was fed to the birds throughout the 5-wk gro wth period (T1), the same basal diet being supplemented with 8.2% Linseed o il (LO, Experiment 1) or rapeseed oil (RO, Experiment 2) in three different periods: the last week before slaughtering at 35 d (T2), the last 2 wk (T3 ), and throughout the experiment (T4). A sensory evaluation of the meat was carried out and its FA profile was determined. Performance parameters were not significantly different among treatments. Removing FO resulted in lowe r values of saturated and higher n-6 FA content, the latter because of the increase in Linoleic acid in both experiments. The amounts of long-chain n- 3 polyunsaturated fatty acids (PUFA) were significantly depressed when FO w as replaced. However, replacing FO by LO resulted in minimal effects on tot al n-3 FA, due to the increase in Linolenic acid. The substitution of EO by RO resulted in a decrease in the n-3 FA content, whereas levels of monouns aturated FA (MUFA) increased in direct relation to the larger amounts of ol eic acid in the diet. Sensory panelists scored as unacceptable those meats from T1 in both experiments. Replacing 1 (T2) or 2 (T3) wk FO wi th vegetab le oil clearly resulted in the improved sensory quality of meat.