Retinol and α‐tocopherol concentrations in whole fish commonly fed in zoos and aquariums

Abstract

Retinol (n = 17 spp.) and a-tocopherol (n = 9 spp.) concentrations in whole fish utilized for captive animal feeding programs were determined by high-performance liquid chromatography (HPLC) following routine storage and preparation after commercial purchase by two zoological institutions. Vitamin A activity was calculated from retinol values and ranged from 55 IU/100 g (immature herring) to >2,000 IU/lOO g (salmon) on an as-fed basis. a-Tocopherol values, a measure of vitamin E activity, ranged from 0.9 IU/100 g (butterfish) to 12.3 IU/100 g (tilapia) on a wet basis. Vitamin levels in whole fish were intermediate to values previously quantified for muscle or liver tissues alone. Vitamin concentrations in fish livers were quantified separately in seven of these species; liver contributed 35-63% of total retinol measured and 8-34% of total a-tocopherol. Based on these analyses, whole fish commonly fed in zoos, aquariums, and marine zoological parks would appear to meet vitamin A requirements established for most species without additional supplementation, whereas levels of vitamin E quantified indicate a need for supplementation of diets for piscivores.

Nutritional composition and digestibility by ocelots (Leopardus pardalis) of whole animals and a commercial diet

“…Our results for the whole animal dietary items are generally similar to other published analyses of those species [e.g. Clum et al, 1996; Dierenfeld, 1993; Dierenfeld et al, 2002]. The exception is the chick fat content, which is much lower than previously reported values for that species [22.4–37.8%; Dierenfeld, 1993; Dierenfeld et al, 2002].…”

“…Clum et al, 1996; Dierenfeld, 1993; Dierenfeld et al, 2002]. The exception is the chick fat content, which is much lower than previously reported values for that species [22.4–37.8%; Dierenfeld, 1993; Dierenfeld et al, 2002].…”

Plasma concentration of α-tocopherol in different free-ranging birds of prey

“…Our data provide basic information about the physiological range of α-tocopherol plasma concentrations in healthy free-ranging birds of prey. Noticeably, besides the fact that meat of freshwater fish contains only low to medium α-tocopherol concentrations, and only the liver contains high concentrations of α-tocopherol (Dierenfeld et al 1991;Lall and Parazo 1995), α-tocopherol plasma concentrations in osprey nestlings did not differ significantly from the concentrations detected in WTSEs and northern goshawks.…”

Plasma tocopherol, retinol, and carotenoid concentrations in free-ranging Humboldt penguins (Spheniscus humboldti) in Chile

“…The concentrations of essential nutrients, particularly vitamins (e.g., vitamin A, vitamin E, and the B vitamins), vary both within and between species of fish, and may decrease with time, even in frozen fish. In addition, the methods used to thaw fish prior to feeding may cause further deterioration in the level of vitamins [Geraci and St. Aubin, 1980;Dierenfeld et al, 1991;Wallace et al, 19921. Both vitamin A (measured as retinol) and vitamin E (calculated from tocopherol) are necessary for normal health and reproduction in birds. Deficiencies of either vitamin can lead to poor fertility, early embryonic death, poor hatchability, suppressed immune function, and high chick mortality, even when adults are only marginally deficient and do not show clinical signs of hypovitaminosis [Jones and Hunt, 1983;West et al, 1992;Sklan et al, 19941.…”