Dietary fennel (Foeniculum vulgare Mill) seeds supplementation affects yield, fatty acid composition and flavour profile of milk and cheese in grazing goats

Fennel (Foeniculum vulgare Mill) is an annual plant belonging to the family of Apiaceae, widely used in Mediterranean areas for its aromatic and medical properties, especially for carminative, digestive and galactagogue effects. In this trial, 20 multiparous goats homogeneous for body weight (BW: 50.0 ± 2 kg), parity (3rd) and milk yield (1940 ± 120 g/head/day), were randomly allocated into two groups (C: control; F: fennel) fed on a permanent pasture (9:00 am to 4:00 pm). In the pen both groups received 400 g of concentrate mixture (barley and corn meals) and group F diet was supplemented with 15 g/head/day of organic fennel seeds. From the beginning of May until September, milk yield was measured daily, and samples of milk and pasture were collected monthly and analysed, along with concentrate, for their chemical composition and fatty acid profile. Cheese samples were obtained at the beginning and at the end of the trial and analysed for chemical composition, fatty acid and VOCs profile. Milk yield was significantly higher in group F (1809.6 g vs 1418.3 g for group F and C respectively), whereas the solid content did not differ between groups. Milk fatty acid profile differed between groups, especially for the content of MUFA, PUFA, and SFA. Cheese production and composition also was different for yield, fatty acid profile and VOCs composition between the groups. Indeed, the cheese of group F had higher antioxidant capacity and 4 aromatic compounds which were completely absent in the cheese of group C. These results confirm the galactagogue activity of fennel seeds in dairy goats and suggest their potential role as feed additive in grazing system to enhance production in terms of yield and antioxidant activity.