Comparison of |w|-6 and w-3 fatty acids ratios in cow's milk between Iranian conventional and industrial production systems

Cow''s milk contains two families of fatty acids; omega-6 and omega-3، which are crucial in human health. It has been shown that the ratio between these two families is connected to the higher risk of chronic diseases. Therefore the ratio between them is more important than their quantity (The most desirable ratio is 1:1). This study was aimed to quantify fatty acids profile and determine the ratio between omega-6 and omega-3 fatty acid families in cow''s milk produced fewer than two different systems (rural and conventional). Twenty cow''s milk samples (10 rural and 10 conventional) from the dairy farms in Khorramabad city-Iran were collected. Fatty acids profiles were determined using gas chromatography. Conventional milk had higher omega-6 (2. 12±0. 4% vs 1. 65±0. 2%) and lower omega-3 (0. 16±0. 03% vs. 0. 21±0. 04%) in comparison with the rural milk. The ratio of omega-6 to omega-3 in rural milk was lower (8 to 1) than that in conventional milk (13 to 1) (p<0. 01). This study showed that milk produced in rural system has a better ratio of omega-6 to omega-3 therefore is healthier for human nutrition. It is also worth to mention that the ratio of omega-6 to omega-3 in cow''s milk produced in both systems is far from the acceptable ratio in human nutrition.