PLASMA CONCENTRATIONS OF VITAMIN A

Area of Science:

• Avian nutrition
• Wildlife health
• Nutritional biochemistry

Background:

• Thawed frozen-fish diets in zoological settings may lead to nutritional deficiencies.
• Humboldt penguins (Spheniscus humboldti) are susceptible to vitamin imbalances.
• Assessing vitamin status is crucial for captive bird health.

Purpose of the Study:

• To evaluate the impact of vitamin A1, D3, E (α-tocopherol), and B1 supplementation on plasma concentrations in Humboldt penguins.
• To determine the vitamin content of thawed frozen-fish diets provided to penguins.
• To assess the adequacy of current diets based on established recommendations.

Main Methods:

• A feeding trial was conducted with 17 Humboldt penguins divided into supplemented and control groups.
• Plasma vitamin concentrations (A1, D3, α-tocopherol, B1) were measured pre- and post-supplementation (70 days).
• Vitamin concentrations in the thawed fish diet were analyzed.

Main Results:

• Vitamin B1 concentrations significantly increased in supplemented penguins.
• Plasma vitamin A1 levels decreased significantly in the supplemented group.
• Vitamin D3 and α-tocopherol showed no significant changes in plasma concentrations.
• Control group showed no significant changes.
• Dietary analysis revealed low vitamin B1 and α-tocopherol, and high vitamin A1 and D3 relative to AZA recommendations.

Conclusions:

• Vitamin B1 supplementation is necessary for Humboldt penguins on thawed frozen-fish diets.
• Vitamin A and E levels can deplete in frozen fish over time.
• Regular monitoring of vitamin concentrations in fish diets is recommended.