摘要
In an attempt to enhance organic omega-3 milk production, a practical study was performing in 7 Holstein dairy farms in Northeast Iran. The experiment was conducted at the ＂ShafashirToos industrial dairy farmers production and distribution cooperative＂ located in Northeast Iran, between June 2010 and December 2010. In Golshid-Mashhad Co., cows were fed with no linseed containing diets （NO-Lin）, while in the other farms （Hanaei Co., Ghasemi Co., Taheri Co., Teliseh Co., Arasp Co. and Navingholshid-Khorasan Co.）, cows were fed diets containing 9% ground linseed （Lin）. Cows were used in a randomized complete block experimental design. Diets were provided as TMR. Concentration of fat, protein and lactose in milk was measured. Milk fat extraction and fatty acid separation were determined. There were no differences in the most of the milk fatty acid profiles of cows in farms that received ground linseed but feeding Lin diets compared with NO-Lin, significantly decreased （P 〈 0.05） C8：0-C16：0 concentration and it increased those of C 18：1 n9trans, C 18：1 n9cis, C 18：2 trans and C 18：3 n3. As a result, farms with Lin diets had better milk fatty acid profiles with doubled in a-Linolenic acid concentration and increased in mono and polyunsaturated fatty acids and decrease in medium chain and saturated fatty acids compared with those of the NO-Lin diet. These results clearly demonstrate the possibility for sustainable production of organic omega-3 milk with levels ofC18：3 FA up to 2.4 times higher than typical levels in dairy fat. The manufacture of omega-3 enriched milk and milk products could supply dietary fatty acids at levels that may henefit health, without the need for unrealistic changes to eating habits.
