The effects of dietary microalgae (Schizochytrium spp.) and fish oil in layers on docosahexaenoic acid omega-3 enrichment of the eggs

Abstract

SummaryNutritional manipulation of diets for layers can help to naturally modify the nutritional content of eggs. The objective of this study was to increase the concentration of the omega-3 fatty acid, docosahexaenoic acid (DHA), in the egg yolk by feeding a diet rich in omega-3 fatty acids from microalgae compared to one containing fish oil to layers. A total of 480 layers (Babcock B308) aged 28 weeks old were divided into four treatment groups with four replicates per treatment. The layers were fed a control diet, a diet containing 4% crude salmon oil, or microalgae (Schizochytrium spp.) at 1% or 2% in the diet for eight weeks. Feed intake and egg production were recorded daily and egg quality tested every two weeks. There were no significant differences between the control and treatment groups as regards feed intake, egg production, egg weight, egg mass, albumin height, and Haugh unit of the eggs. The egg samples were obtained at the start of the trial, four weeks and eight weeks for the analysis of the fatty acid profile in the eggs. The DHA level in the eggs from layers fed even 1% or 2% algae was higher (P < 0.05) compared to the level from those fed with the control diet and 4% fish oil supplementation. The omega 6:3 ratio in eggs was significantly reduced (P < 0.05) compared to the control diet and the fish oil groups. Feeding 2% microalgae (Schizochytrium spp.) in hen diet resulted in an increase in the DHA level (above 100 mg/egg) and a decrease in the omega 6:3 ratio to the optimal level. The trial demonstrated that DHA concentration in eggs can be enriched through nutritional management of layers by using algae supplementation in order to provide more favourable fatty acids for consumers.