Elephants Elephants - Wildpro - Twycross Zoo

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product based on this compound 1. Although depressed levels of plasma
vitamin E have been observed in elephants, inhibited absorption of vitamin E
has not been clearly documented (Dierenfeld 1999). Evaluating the efficacy of
TPGS for endangered species and its incorporation into tissues (apart from
blood) urgently needs to be undertaken. Potential for long term toxicity due
to bioaccumulation of the carrier molecule should be monitored; excretion is
known to be quite low (Traber et al 1988).
It has been estimated that captive elephant diets should aim to provide 130-
167 IU/kg DM vitamin E in the diet to achieve circulating α-tocopherol levels
similar to those seen in wild elephants, (Dierenfeld and Dolensek 1988). The
zoo diets analysed in this study contained an average of 60.3 IU vitamin E/kg,
however there was an extremely wide variation in the vitamin E content of the
diets between the collections. Those collections with the lowest vitamin E
concentrations did not feed El-E-Vite or other vitamin supplements. One
collection had stopped feeding a vitamin E supplement having tested serum
α-tocopherol levels in their elephants and finding similar levels to those seen
in wild elephants and so this diet also contained very low levels of vitamin E.
Appendix 6 provides a recommendation on vitamin E supplementation,
taking into account our current knowledge and, due to confusion about
supplement form and efficacy, compares several different products available
in the UK on the basis of potency and relative cost.
Summary
Generally, the diets being fed to elephants held in British and Irish zoos seem
adequate.
• Fibre levels are sufficient, however care should be taken to feed hays
with an acid detergent fibre (ADF) level of above 30% to prevent colic.
• Browse may play an important role in elephant diets for the provision
of essential fatty acids as well as providing environmental enrichment,
and collections should ensure that elephants are provided with a
regular fresh (or frozen) supply.
• Protein levels seem adequate, but it is very difficult to be certain unless
analysis of the hay fed is carried out.
• Calcium and phosphorus levels are acceptable.
• Sufficient sodium is provided.
• Analysed iron and zinc levels seem low, but this is likely due to missing
data on forage composition rather than a true deficiency. Elephants
should be closely monitored for signs of deficiencies in these minerals,
and diets should be supplemented with caution.
• Vitamin E levels in the analysed diets varied widely between
collections. All collections (except for Colchester and Whipsnade) did
not provide the recommended levels of vitamin E in the diet.
1 In the UK Mazuri Zoo Foods manufacture El-E-Vite. It contains TPGS and increased levels of
calcium, sodium and potassium. It is designed to be used along with normal concentrate and
bulk feeds e.g. equid diet, some fruit and vegetables, good quality hay and browse.