Among its long chain fatty acids linseed contains a-linolenic acid (ALA), which belongs to the group of V3 fatty acids. An increased V3/V6 ratio is believed to have favourable effects on individuals' health by an anti-inflammatory effect. Furthermore, beneficial effects of increased V3 fatty acids might possibly be expected for the meat consumer.

The aim of this preliminary study was to investigate whether an orally given linseed complementation would modify the fatty acid composition of red blood cells in sheep.

Five four months-old Texel-crossed lambs weighing 33.1 ± 1.3 kg were fed with grass silage ad libitum and supplemented with concentrate (1280 g/day) containing 14% linseed during a period of 3 weeks. Each animal underwent venous blood sampling before and after the supplementation trial. Red blood cell fatty acid composition was determined using gas chromatography coupled with flame ionization detectors.

Linseed complementation significantly increased w3 docosapentaenoic acid (DPA, 0.40 ± 0.12 versus 0.52 ± 0.08 mole%, p < 0.05) in red blood cell membranes, whereas a-linolenic acid (ALA, 0.57 ± 0.46 versus 1.02 ± 0.89 mole%, ns), eicosapentanoic acid (EPA, 0.97 ± 0.52 versus 1.48 ± 0.25 mole%, ns) and docosahexaenoic acid (DHA, 0.15 ± 0.06 versus 0.16 ± 0.06 mole%, ns) did not significantly increase. Several w6 fatty acids significantly increased: dihomogammalinolenic acid (DGLA, 0.15 ± 0.02 versus 0.20 ± 0.02 mole%, p < 0.05), arachidonic acid (AA, 1.31 ± 0.32 versus 1.73 ± 0.24 mole%, p < 0.005), adrenergic acid (ADRA, 0.22 ± 0.22 versus 0.41 ± 0.35 mole%, p < 0.05). Linoleic acid (LA, 1.11 ± 0.12 versus 1.22 ± 0.03 mole%, ns) and gamma-linoleic acid (GLA, 0.04 ± 0.01 versus 0.05 ± 0.02 mole%, ns) did not increase significantly. Decrease of w6/w3 ratio did not reach significance (6.88 ± 1.93 versus 4.86 ± 1.47 mole%, ns).

These data suggest that a 3-week period of linseed complementation is of sufficient duration to change red blood cell fatty acid composition in sheep. However, the expected increase in ALA was not significant and several w6 fatty acids were also increased, thereby preventing the w6/w3 ratio to decrease.

In conclusion of this preliminary study, linseed complementation does not allow to increase exclusively w3 fatty acids and the potentially beneficial effects of an increase in DPA might be counterbalanced by increased w6 fatty acids.