177 Effect of dietary choline and Schizochytrium oil on DHA content in the egg yolk and egg quality during storage.

摘要

The study was conducted to investigate the effects of dietary choline and oil (SO) on docosahexenoic acid (DHA) content in egg yolk and egg quality during storage. Six hundred and thirty 28-week-old laying hens were randomly assigned into 7 dietary treatments (1 + 2 × 3 factorial arrangement) that were supplemented with 0.05% choline (control), 0.1% choline +0.5% SO, 0.1% choline +1.0% SO, 0.1% choline +1.5% SO, 0.15% choline + 0.5% SO, 0.15% choline + 1.0% SO, or 0.15% choline + 1.5% SO, respectively. Each treatment contained 6 replicates with 15 birds each. Birds were fed the control diet for 1 week and then the corresponding experimental diets for 12 weeks. The results showed that egg yolk color deepened with the increasing level of SO. The amounts of n-3 polyunsaturated fatty acid and DHA in per egg increased with the elevation of SO supplementation, while their enrichment efficiency decreased. The Choline group improved yolk DHA enrichment efficiency compared to the Choline group. Dietary choline supplementation improved DHA enrichment efficiency in layers fed a 0.5% SO diet. The DHA enrichment efficiency was 34.01% when birds fed Choline -SO diet. Egg weight loss and yolk percentage increased with the increase of storage time at 4℃. Yolk color in SO groups were deeper than that in control group when stored for 30 days at 4℃. Yolk malondialdehyde (MDA) content increased with the increasing storage time and the elevation of SO level. The increase of MDA and decline of DHA gradually emerged before 20 days, while rapidly accelerated after 20 days. Overall, based on DHA content and enrichment efficiency, dietary choline and SO content were recommended as 0.05~0.1% and 0.5%~1.0%, respectively. The best edible time for DHA enriched eggs was recommended before 20 days.