Does dietary vitamin E or C decrease egg yolk cholesterol?

Area of Science:

• Animal Nutrition
• Biochemistry
• Poultry Science

Background:

• Dietary antioxidants, such as vitamins E and C, are often supplemented to improve animal health and product quality.
• The precise effects of these vitamins on serum metabolites and egg quality in layer hens require further investigation.

Purpose of the Study:

• To evaluate the impact of dietary vitamin E and C supplementation on serum metabolites, yolk cholesterol, egg quality, and performance of Hy-Line W-36 layer hens.
• To investigate the dose-dependent effects of these vitamins on key physiological and production parameters.

Main Methods:

• 168 Hy-Line W-36 layer hens were assigned to seven treatment groups, including a control and six levels of vitamin E or C (100, 200, 400 mg/kg).
• Supplementation lasted for 4 weeks, with data collected on hen performance, egg quality parameters, yolk cholesterol, and serum metabolites.

Main Results:

• No significant effects of vitamin E or C on hen performance (egg production, egg weight, feed consumption) were observed.
• Egg yolk cholesterol concentrations decreased linearly with antioxidant supplementation (P < 0.01).
• Antioxidant supplementation increased serum glucose, decreased HDL-cholesterol, and increased LDL-cholesterol, challenging existing hypotheses about antioxidant roles in lipid metabolism.

Conclusions:

• Dietary vitamin E and C effectively reduce egg yolk cholesterol in layer hens without compromising performance.
• The observed alterations in serum lipid profiles (decreased HDL-C, increased LDL-C) suggest a complex interaction that warrants further research, potentially revising current understanding of antioxidant functions.
• Vitamin E demonstrated greater efficacy than vitamin C in modulating these specific metabolic parameters.