PLASMA CONCENTRATIONS OF VITAMIN A 1 , B 1 , D 3 , AND E IN HUMBOLDT PENGUINS ( SPHENISCUS HUMBOLDTI) BEFORE AND AFTER DIETARY VITAMIN SUPPLEMENTATION OF THEIR FISH DIET.

In a practical feeding trial at Ouwehand Zoo, plasma concentrations of vitamin A1 , calcidiol (D3 ), α-tocopherol (E), and B1 in 17 Humboldt penguins ( Spheniscus humboldti) were measured before and after supplementation to gain insight into the effect of supplementing these vitamins in animals being fed thawed frozen-fish diets. None of the penguins received vitamin supplements for at least 6 mo before the supplementation trial, which was conducted prior to their normal nesting and molting period. During the trial period, eight penguins received daily vitamin A1 , D3 , tocopheryl acetate, and B1 supplementation placed in their fish immediately prior to feeding and nine control penguins received no supplementation. Concentrations of vitamins A1 , D3 , α-tocopherol, and B1 were also measured in the thawed ready-to-feed fish. Concentrations of vitamins B1 and α-tocopherol were below the Association of Zoos and Aquariums (AZA) recommendations for penguin diets, while concentrations of vitamins A1 and D3 were far above AZA recommendations. At the start of the study and after 70 days of supplementation, plasma concentrations were determined for these vitamins. Vitamin B1 concentrations in plasma increased significantly ( P < 0.05) between Day 0 (mean 39.9 μg/L) and day 70 (mean 160.5 μg/L) in the supplemented group. Plasma vitamin D3 and α-tocopherol did not show a significant change. Vitamin A1 levels in the supplemented group decreased significantly from 1.65 mg/L on day 0 to 1.4 mg/L on day 70. In the control group no significant changes were observed. The results of the study support the necessity of supplementing vitamin B1 in penguins fed thawed frozen fish. Depletion of vitamin A and E concentrations in frozen food fish over time support recommendations to regularly measure vitamin concentrations in different batches of frozen fish.