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.

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Plukenetia volubilis L. leaves were part of the traditional diets in many countries. P. volubilis leaves were used to make tea and sold as local products in Thailand. There is less information on the composition of P. volubilis leaves. Previous study revealed that roasted leaves extract with hot water showed the highest antioxidant activity and the antioxidant property might be due to the presence of flavonoid. The present study was carried out to determine the quercetin content in P. volubilis leaves extract and evaluate the anti-aging potential activities including MMP-2 inhibition activity and telomerase stimulation activity. P. volubilis leaves were roasted in hot air oven and extracted with hot water. The extract was investigated for quercetin content by high-performance liquid chromatography (HPLC). In vitro cytotoxicity, MMP-2 inhibition activity and telomerase stimulation activity were determined for anti-aging properties. The results revealed that P. volubilis leaves contained quercetin 50.50±4.78 mg/g DW. The extract showed no cytotoxicity on human skin fibroblast with cell viability of 96.76-120.83%. It demonstrated the potential of MMP-2 inhibition (8.74±2.84%) activity but lower than ascorbic acid. P. volubilis leave extract did not have telomerase stimulation activity on the human Hela cell line. However, the results from this study have indicated the possibility of anti-aging potential of P. volubilis leaves extract.