Fatty Acid Profile and CLA Content of Goat Milk: Influence of Feeding System

There is great interest in producing bioethanol from biomass and there is much emphasis on exploiting The effect of pasture and of diet linseed supplementation on fatty acid profile of milk was evaluated using 45 pluriparous goats, equally divided after kidding into three homogeneous groups (H, P and L). Group H (control) and L were housed in a stall receiving alfalfa hay, while group P was led to pasture. The groups received concentrate which for group L had linseed as ingredient. Average milk yield did not statistically differ between the groups. Groups P showed significantly higher fat content than group H and L (4.62% vs 3.70%, and 3.90% respectively for groups P, H and L; P < 0.01). On the contrary, milk from goats of group H and L had significantly higher content of lactose (4.65% and 4.61% vs 4.57%, respectively for groups H, L and P; P < 0.05). The levels of C18:1 cis9, C18:1 trans11 and MUFA in milk were significantly (P < 0.05) increased by both the pasture and linseed, while linoleic acid (C18:2) and PUFA were significantly (P < 0.05) higher in group P compared either to H or to L groups. The highest values of CLAs, either as t11 CLA and t10 c12 CLA or as SCLA, have been registered in milk of group P, the lowest in group H. These parameters in milk of group L were significantly (P < 0.05) lower or higher than those of group P and H, respectively.