Dietary choline supplementation regulated lipid profiles of egg yolk, blood, and liver and improved hepatic redox status in laying hens.

Five hundred and forty 19-wk-old HyLine Brown laying hens were randomly distributed to 6 dietary treatments and fed 1of 6 corn-soybean meal-based diets added into choline with 0, 425, 850, 1,700, 3,400, and 6,800 mg/kg to investigate effects of dietary choline supplementation on lipid profiles of egg yolk, serum and liver, and hepatic redox status of laying hens. Yolk weight and total lipid, triglyceride, cholesterol and phosphatidylcholine, serum triglyceride, cholesterol, apolipoprotein B 100 (apoB 100), and very low density lipoprotein (VLDL), and liver relative weight, total lipid, triglyceride and apoB 100 as well as hepatic total superoxide dismutase and glutathione peroxidase (GSH-Px) activities, total antioxidant capacity (T-AOC), and malondialdehyde (MDA) in laying hens at weeks 58 and 68 of age were determined. The differences (P < 0.001) were caused by choline treatments in yolk phosphatidylcholine (at 850 mg/kg or more choline), serum VLDL, and liver triglyceride (at 1,700 and 3,400 mg/kg choline) of birds, at weeks 58 and 68 of age, and yolk total lipids were elevated (P < 0.05) by supplemental choline at 3,400 mg/kg whereas liver total lipids were reduced (P < 0.05) by 1,700 and 3,400 mg/kg choline addition. Hens fed diets supplemented choline had higher (P = 0.005) liver GSH-Px activity (with 3,400 mg/kg choline) and greater (P = 0.014) T-AOC (with 1,700 mg/kg choline) than those fed diets with 0 and 425 mg/kg choline addition. Choline affected serum VLDL, liver total lipid, triglyceride and apoB 100 at weeks 58 and 68 of age and hepatic GSH-Px activity, T-AOC and MDA at week 68 of age quadratically (P < 0.05), whereas it influenced total lipid and phosphatidylcholine of egg yolk linearly (P < 0.05) and quadratically (P < 0.05). In conclusion, dietary choline supplementation elevated yolk total lipid and phosphatidylcholine and serum VLDL, reduced liver total lipid and triglyceride, and enhanced hepatic GSH-Px activity and T-AOC in laying hens.