Fatty acid profile in milk of Bovec sheep fed in the stable or grazed in different pastures

The fatty acid profile in the milk of Bovec sheep fed total mixed ratio (TMR) and grazed natural pastures in the lowland (480 m altitude) supplemented with the second harvest (L) as well as grazed different altitude mountain pastures; M1 (1100- 1300 m altitude), M2 (1600-1700 m altitude), M3 (1800 m altitude), M4 (1900 m altitude), M5 (2200 m altitude) were determined. There was an important effect when ewes were turned from the stable to the pasture on all fatty acids. The percentage of α-linolenic acid (ALA), arachidonic acid (ARA) and docosahexaenoic acid (DHA) increased significantly (P<0.001) with the diet. In the milk from M5 grazing the percentage of ALA was 2.5 times higher than in milk from L and 2.6 times higher than in milk from TMR. The percentage of ARA and DHA in milk was the highest when ewes were grazing on the M5 pasture (0.21±0.02 wt. %; 0.22±0.02 wt. %) respectively. Total n-3PUFA and n-6PUFA increased significantly (P<0.001) by the diet. Therefore, the n-6/n-3PUFA ratio was the best (1.2) in milk produced in the highest mountain pasture (M5), in terms of nutritional requirements.