Ellen S. Dierenfeld

Wildlife Conservation Society, Bronx, NY 10460 USA

Increasingly recognized as an essential foundation of sound animal management, health, and
reproduction programs, comparative nutrition, as a scientific discipline, can realize expansive goals
through integrated efforts to maximize Personnel, Communications, and Analytical resources. Indeed,
the challenge for applying scientifically based animal management principles in the zoo profession globally, and recent mandates in animal welfare and inspection processes with respect to defined
feeding programs, provide an exciting and timely catalyst for growth with almost unlimited potential. Over the past decade, both the American Zoo and Aquarium Association (AZA) as well as the European Association of Zoos and Aquariums (EAZA) have initiated nutrition disciplinary specialist
groups, the Comparative Nutrition Society was formed, and the Conservation Breeding Specialist Group affirmed the value of a nutrition-based Working Group. Despite these umbrella organizations,
the need for implementing nutrition programs at the local level is still apparent; fewer than 25% of US
and European zoos employ nutritionists, with the percentage even lower elsewhere in the world.
Globally, no specific academic programs, scientific disciplinary qualifications, nor licensure examination have been established which standardize training for a career as a zoo nutritionist,
resulting in overlapping responsibilities that may be better served by another discipline such as food
scientist or food service manager. As important as basic food handling and service aspects are in
providing quality diets to zoo collection animals, specific training in biochemical evaluation of diets
and comparative physiology provides a unique role for the zoo nutritionist. Many of the essential
functions of safety and quality assessment, as well as provision of sound diets, can be met through
Internet-shared communications that should be a priority of future focus. Maximal information
exchange, with minimal duplication of effort, can be realized through the joint creation of accessible
databases of Food Composition, Diet Evaluation, Nutrient Recommendations, Food Storage and
Handling Protocols, Physiological Assessment Criteria, and a library of Bibliographic References.
This trend has been initiated within The Netherlands through the adoption of a national standard diet
assessment tool (ZootritionTM) by the Dutch Federation of Zoos, and creation of national databases of
food composition and diet registry. Overlap between the zoo nutrition specialist groups of AZA and
EAZA are apparent at biannual meetings, training workshops, and through joint husbandry manual
authorship. The Zoo Conservation Outreach Group and Toronto Zoo have led similar efforts within
Latin American zoological facilities. WildProâ, an electronic encyclopedia of wildlife health and
management, provides an example of integrated nutrition data in its web-based network for
widespread global dissemination, and may be considered a primary resource for health professionals
as well as the rehabiliation/reintroduction communities with which nutritionists need to interface.
Linking information within an electronic framework also allows more rapid integration with other
disciplines (i.e. reproduction, immune function, genetics) to advance the sciences. Finally, separate and apart from the resulting data, integrated analytical laboratory methodologies must be implemented to fill gaps in global databases, which most effectively meet the needs of the zoo nutrition community and provide accurate information on a timely basis.


M. Clauss, E. Kienzle and J-M Hatt

Institute of Animal Physiology, Physiological Chemistry and Animal Nutrition, Munich, Veterinaerstr. 13, D-80359 Muenchen, Germany; 2Zurich Zoo and Division of Zoo Animals and Exotic Pets, University of Zurich, Winterthurerstrasse 260, CH – 8057 Zurich

We present a review on the feeding practice, the nutritional pathology and the documented utritional peculiarities of zoo ruminants. Historically, the difference in chemical composition between browse and grass led to the conclusion that browsers need a diet lower in fibre and higher in protein than grazing ruminants. The term concentrate selectors“, coined to describe browsing ruminants, additionally focused the attention on the chemical nature of a browser’s diet assumed high in easily fermentable, soluble nutrients. In comparative nutritional surveys, browsing ruminants in zoos tend to consume less fibre, more protein and more nitrogen-free extracts than grazers. While this could be interpreted as a reflection of their nutritional needs, this feeding type displays, in comparative pathological surveys, a higher incidence of acidotic changes in the ruminal mucosa, indicating that this group does not ingest sufficient amounts of fibrous material. Additionally, data from controlled bilance trials does not support the notion that browsing ruminants have higher protein requirements. We suspect that the lesser fibre intake in browsers is due to their reluctance to ingest hay, the commonly used fibre source, which is usually offered ad libitum. Reluctance to ingest hay and digestive problems after hay ingestion have been reported for different browsing ruminant species. There is reason to believe that it is not only the chemical but also the physical difference between grass and browse that affected the evolution of different feeding types. Attention within the zoo community should focus on providing browsers with a fibre source that corresponds to the physical characteristics of their natural forage.


E.J. Flach1* and M. Clauss1,2

1Veterinary Science Unit, Institute of Zoology, Whipsnade Wild Animal Park, Dunstable, Beds. LU6 2LF, United Kingdom; 2Institute of Animal Physiology, Physiological Chemistry and Animal Nutrition, Munich, Veterinaerstr. 13, D-80359 Munich, Germany

Copper deficiency has been diagnosed or suspected in a number of ruminants at Whipsnade Wild Animal Park including bontebok (Damaliscus dorcas), European bison (Bison bonasus), wapiti (Cervus elaphus) and yak (Bos grunniens). Prior to 1992 the yak diet was supplemented with copper sulphate, but the inclusion rate was variable and never greater than 180mg copper per adult per day. Between 1992 and 1994 it became evident that the herd was still suffering from a range of conditions which may be associated with copper deficiency including chronic diarrhoea, poor body condition and dull coat. The copper concentration in blood samples taken from animals immobilised for clinical or management purposes in 1994 ranged from 0.8 to 3.3µmol/L (mean 1.8, n=10), well below the normal cattle range of 9 to 19µmol/L. The copper supplement was therefore increased to 720mg copper per adult per day (1.8g copper sulphate) starting in September 1994, and over the period 1995-97 blood copper concentrations rose steadily. In 1995 they ranged between 2.4 and 13.8µmol/L (mean 6.7, n=9), and in 1997 between 6.4 and 16.6µmol/L (mean 10.7, n=8). Over the same period the incidence of diarrhoea decreased and general body and coat condition improved. Also the herd size grew, possibly due to an increase in fertility and neonatal survival. Other factors which may have been involved in the improvement in the health of the herd were the importation of a new herd male in 1992, and an intensification of anthelminthic treatment over the same period. Hair depigmentation appeared in the autumn of 1998 in ten calves born during that summer. They had blood copper oncentrations of 0.8 to 5.0µmol/L (mean 2.8), two yearlings also had low concentrations (0.5 and 1.3µmol/L), but an adult female sampled at the same time had a value of 8.4µmol/L, just below the normal range. This suggested that the older animals were taking all of the copper-supplemented concentrate pellets before the calves gained access to feeding troughs. The calves were injected with 62.5mg copper heptonate (Cuvine, C-Vet) and no further clinical signs were seen.


W. Arnhold1* and M. Anke2

1AGROTEX-Chemie GmbH, Altneundorf 58, D-01796 Pirna, Germany; 2Friedrich Schiller University, Biological-Pharmaceutic Faculty, Institute for Nutrition and Environment, Dornburger Str. 24, D-07743 Jena, Germany.

Zinc (Zn) belongs to the essential food components. It is part or activator of more than 200 enzymes. The effect of marginal Zn intake on growth, reproduction performance, quality of skin and hair, and life expectancy are well known. However, the diagnosis of the trace element status in living wild animals kept in zoos is difficult since, as a rule, only blood, hair, claws and excretions are available for this purpose. The capacity of indicating the trace element status of several tissues is element-specific. Therefore, not all of them are suited as indicator tissues for the trace element status. Furthermore, it must be taken into consideration that the indicating capacity of organ tissues in the case of deficiency can be different from that in the case of exposure. The investigation of these laws could not be carried out in endangered species of ruminants, but in farm animals. For that reason, organ tissues of different species of wild ruminants kept in captivity were obtained at necropsy, analysed and compared with datas of domestic and wild living ruminants. The wild ruminants which were kept in captivity came from the Zoological Society of San Diego and from the Zoo Leipzig. For comparison, organ tissues from wild living and domestic ruminants were obtained from different locations in the states of Germany and Northern California. After dry ashing of samples the Zn concentration were analyzed by atomic absorption spectroscopy (Jarrell Ash 850) or optical emission spectroscopy with inductively coupled plasma (Spectroflame D, Spectro Analytical Instruments). The Zn status of different ruminants depends on species, age and - due to the homeostatically regulation - to a lesser extent on Zn intake. The results are discussed and compared with the status of further elements which have an antagonistic effect on the Zn status. The Zn limit value of the indicator tissues for a sufficient Zn supply are given in the species of wild ruminants.


D.B.R. Wandrag¹*, P. Eloff² and R.H.Willats2

1Onderstopoort, University of Pretoria, Pretoria, 0182, South Africa; ²WES Enterprises (Pty) Ltd, PO Box 340, Thabazimbi, 0380, South Africa

Game and cattle farming is very prominent in the northern semi-arid regions of South Africa. The average rainfall is 400 mm per year. Due to a few very dry seasons and poor beef prices many farmers incorporated game farming in their strategy to survive. Hunters from abroad pay prices that exceed carcass meat value by far. Unfortunately adequate compensation for carrying capacity of game species was generally not made and severe bush encroachment resulted due to mismanagement. However, encroachment bush itself is a natural source of prime food for herbivores. Herbicides are used to kill the encroachment bush but some of them have a long residual effect, also killing grass and desirable trees, some of which are hundreds of years old. Heavy downpours shortly after applications can wash chemicals into natural streams. Dead bushes had to be burnt resulting in rehabilitation taking five to seven years and thus proving to be very expensive. In 1995 an entrepreneur working in wildlife and ecological services implemented a survival strategy for this problem. Specifically designed motorised saws are used to cut off encroachment bush at ground level preventing sharp wooden spikes causing foot injuries. It also prevents high tannin levels in the plant compared to stress like chronic browsing or axing. The bush is shredded on site in a robust mill. The product is sun-dried, hammer-milled and fortified with carefully formulated natural supplements before it is pelletised. The final product, trade marked as BOSKOS (bush feed) contains 10% crude protein, maximum 35% fibre, minimum 2.5% fat and total digestible nutrients amount to 60%. BOSKOS is produced from Acacia, Dichrostachus, Combretum and Grewia spp. is now a staple diet in zoos, havens for endangered species, and especially as a winter grazing supplement in national parks and game reserves around the world. BOSKOS is a primary source product in its own right. It is therefore significantly different from most other commercially - produced animal feeds in that it is not a by-product of a manufacturing process. BOSKOS is also an excellent diet supplement for orphan animals and has been especially successful for animals reared to adulthood and re-introduced to the wild. Acacia is a natural diet for wild animals, rich in natural trace elements drawn from deep in the earth by the root systems and retained in the processing of the final product. Herbivores in captivity instinctively appear to recognise BOSKOS as a foodstuff that is natural to them.