Conversion of α-linolenic acid to long-chain omega-3 fatty acid derivatives and alterations of HDL density subfractions and plasma lipids with dietary polyunsaturated fatty acids in Monk parrots (Myiopsitta monachus)

Abstract

The effect of α-linolenic acid from a flaxseed (FLX)-enriched diet on plasma lipid and fatty acid metabolism and possible atherosclerosis risk factors was studied in Monk parrots (Myiopsitta monachus). Twenty-four Monk parrots were randomly assigned to diets containing either 10% ground SUNs or 10% ground FLXs. Feed intake was calculated daily. Blood samples, body condition scores and body weights were obtained at -5 weeks, day 0, 7, 14, 28, 42 and 70. Plasma samples were analysed for total cholesterol, free cholesterol, triacylglycerols and lipoproteins. Phospholipid subfraction fatty acid profiles were determined. By day 70, the FLX group had significantly higher plasma phospholipid fatty acids including 18:3n-3 (α-linolenic acid), 20:5n-3 (eicosapentaenoic acid) and 22:6n-3 (docosahexaenoic acid). The sunflower group had significantly higher plasma phospholipid levels of 20:4n-6 (arachidonic acid). By day 70, the high-density lipoprotein (HDL) peak shifted resulting in significantly different HDL peak densities between the two experimental groups (1.097 g/ml FLX group and 1.095 g/ml SUN group, p = 0.028). The plasma fatty acid results indicate that Monk parrots can readily convert α-linolenic acid to the long-chain omega-3 derivatives including docosahexaenoic acid and reduce 20:4n-6 accumulation in plasma phospholipids. The reason for a shift in the HDL peak density is unknown at this time.

Keywords: Myiopsitta monachus; high-density lipoprotein; lipoproteins; polyunsaturated fatty acids.