Effect of Dietary Marine Microalgae (Schizochytrium) Powder on Egg Production, Blood Lipid Profiles, Egg Quality, and Fatty Acid Composition of Egg Yolk in Layers

다국어 초록 (Multilingual Abstract)

Two hundred and sixteen Institut de S$\acute{e}$lection Animale (ISA) brown layers (40 wks of age) were studied for 6 wks to examine the effect of microalgae powder (MAP) on egg production, egg quality, blood lipid profile, and fatty acid concentration of egg yolk. Dietary treatments were as follows: i) CON (basal diet), ii) 0.5% MAP (CON+0.5% Schizochytrium powder), and iii) 1.0% MAP (CON+1.0% Schizochytrium powder). From 44 to 46 wks, egg production was higher in 1.0% MAP treatment than in control treatment (linear, p = 0.034); however, there was no difference on the egg production from 40 to 43 wks (p>0.05). Serum triglyceride and total cholesterol were significantly reduced in the groups fed with MAP, compared to those in groups fed with control diets (Quadratic, p = 0.034 and p = 0.039, respectively). Inclusion of 0.5% MAP in the diet of layers improved egg yolk color, compared with hens fed with basal diet at 46 wks (quadratic, p = 0.044). Eggshell thickness was linearly increased in MAP-fed treatments at 46th wk (p<0.05). Concentration of yolk docosahexaenoic acid (DHA; C22:6n-3) was increased in treatment groups fed with MAP (linear, p<0.05). The n-6 fatty acids, n-6/n-3 fatty acid, and unsaturated fatty acid/saturated fatty acid were decreased in treatment groups fed with MAP (linear, p<0.05). These results suggest that MAP improved the egg production and egg quality, and may affect serum lipid metabolites in the layers. In addition, MAP increases yolk DHA levels, and deceases n-6/n-3 fatty acid ratio.