Fatty acid composition of mountain milk from Switzerland: Comparison of organic and integrated farming systems

During a 12-month study, bulk-tank milk was collected monthly from 3 dairies each of which collected both organic and conventional milks (from integrated farming) in the mountain regions of Switzerland. All milk samples were analyzed for fatty acid (FA) composition. Organic and conventional milks did not significantly differ with respect to saturated FA (SFA) nor trans FA contents, but organic milk had significantly higher contents of polyunsaturated FA (PUFA) (+5.5%; P ≤ 0.001), conjugated linonenic acid (CLA) (+14.9%; P ≤ 0.001), n-3 FA (+12.3%; P ≤ 0.001) and branched FA (+4.7%; P ≤ 0.001). Conventional milk had higher contents of monounsaturated FA (MUFA) (+2.3%; P ≤ 0.05) and n-6 FA (+4.2%; P ≤ 0.01). Significantly higher levels of grasses and lower levels of cereal concentrates in the fodder of organic farming could well explain these results. The differences in the fatty acid composition of milk between the two farming systems were nevertheless small because of low differences in the fodder composition.