Nutrition knowledge

Zoo animal nutrition and nutritional wisdom of zookeepers

A. de Bruin1, N. de Haan1, M. van der Laan1, K. Slotman1, J.Nijboer2, W.L Jansen2,
T.R. Huisman1

1Dept of Animal Management, Van Hall Instituut, Leeuwarden, The Netherlands, 2 European Zoo Nutrition Centre, Amsterdam, The Netherlands

During the last decades many developments took place in zoo animal nutrition. Knowledge has increased significantly. Both in Europe and the USA conferences on this subject are organised almost on a yearly basis which have resulted in many, often useful, publications.
In most of the publications and also in oral presentations during nutrition conferences the (potential) role of zoo keepers in zoo animal nutrition did not get much attention. This is a rather strange phenomenon; zoo keepers are the persons in a zoo closest to the animals. Through daily observation they probably know best how animals react on their diet and should therefore play a key role in the evaluation of all operations related to nutrition. Another important aspect is that they are the persons responsible for implementation of new diets resulting from new insights.
Based on observations in the Dutch zoo community there is a surmise that the potential important role of zoo keepers in implementation and evaluation of zoo nutrition is not everywhere recognised or appreciated.
A research project was started to get more insight in the present and potential activities of zoo keepers in relation with nutrition, information flows in zoos and obstacles for the implementation of new insights. This project was carried out in 2003.
With a standardised questionnaire keepers and other zoo employees in seven Dutch EAZA zoos were questioned extensively. Questions were asked about nutritional knowledge, time spend on nutrition related activities, importance of nutrition related activities for job satisfaction, organisation of communication about nutrition topics and obstacles for carrying out activities related to nutrition.
In total 82 keepers and 17 other employees (veterinarians, curators, and nutritionists) responded. About 70% of the zoo keepers followed secondary agricultural education. Slightly more than 50% of the zoo keepers stated that during formal education zoo animal nutrition was not a subject in the curriculum. But only 17% followed an application course on this subject afterwards.
Over 80% of the zoo keepers stated that they got a lot or most job satisfaction from activities related to feeding. Especially the actual feeding and applying food items as environmental enrichment were considered most satisfactorily. On the other hand, weighing food or weighing food left overs were considered least satisfactorily. Although 75 % of the keepers answered that it was necessary to keep records of amount of food offered and food intake, only 15% actually weighed the food before offering.
Slightly less than 50% considers the present diet as the best possible for the animals. Only 15 % thinks that nothing can be improved in the diets. More than 80% of the keepers indicated that they followed occasionally their own insights when feeding the animals.
Results also show that there is hardly any formal communication between keepers and other staff about nutrition of the animals. It seems that better use of keepers experience and knowledge in zoo nutrition is possible.

Analysis of different fish-handling, storage and thawing techniques in eight Zoos in the Netherlands

E. Griffith1, J. Spiertz1 , J.Nijboer2, L.J.A.Lipman1

1Department of Public Health and Food Safety, Faculty of Veterinary Medicine, Utrecht University, The Netherlands. 2 EZNC, Amsterdam, The Netherlands

Many fish-eating animals living in zoos are fed thawed fish. For a constant daily supply it is necessary to purchase commercially prepared, large blocks of whole frozen sea fish. These fish blocks remain frozen and stored until time of use. Fish has a perishable nature. Therefore it is very important that the fish received in bulk is appropriately handled from the time of receiving, until the actual time of feeding the fish. This way the zoo-animals are guaranteed to be fed good quality fish and receive all the necessary nutrients for their normal growth, health and reproduction.
The contributing zoos all have their own thoughts and theories about thawing frozen fish and correct hygienic practices. This may lead to a difference in the quality of the product. To compare the zoos in their methods of storage, thawing and feeding the fish a questionnaire was made, which contained 75 questions about the subject. During the visits to the zoos, persons working with fish (ordering, thawing, and/or feeding the fish) were questioned about their routines.
After questioning, tours through the parks were made and the different areas were visited. The methods used for working with the fish in each unit of the participating zoos were noted and pictures of each specific situation were taken.
The methods of fish handling differ significant amongst the various zoos. Even within the same zoo different methods were used. Each zoo had several points that could be improved. This could be different steps in the whole fish handling process: ordering, receiving, storing, handling, thawing, feeding, hygiene and sanitation.

Microbiological analysis of frozen and thawed fish in Rotterdam Zoo

J.I.C. Pennings1, J.Nijboer2, L.J.A.Lipman1

1Department of Public Health and Food Safety, Faculty of Veterinary Medicine, Utrecht University, The Netherlands, 2Rotterdam Zoo Blijdorp, The Netherlands

The fish-eating animals in the Rotterdam Zoo are fed slightly frozen or thawed fish that is taken from the freezer in the morning and put in a fridge where it is slowly thawed for 48 hours. The fish-eating animals eat from this set of fish in the morning, in the afternoon and when there is still some left the next morning. Spoilage of fresh fish and lightly preserved fish is caused by microbiological action. This article will describe the degree of microbiological contamination on the skin or in the fish in whole of three different fish species in four different stages, from frozen fish (stage A) till a fish thawed for 72 hours (stage D). Stage C and D are compared to stage A, because the biggest increase in bacteria is suspected in those stages (the longer the fish is kept). It seems that stage D (especially the mackerel) has an increase of more than log 2 microorganisms in a lot of cases. This is a substantial increase and it would be a good idea not to keep the fish until stage D. Mackerel left after stage C should be discarded.

The Comparative Nutrition Database: International Zoo Animal Nutrition

D. A. McWilliams1, M. Delorme2

1CAZA-NARG, AZA-NAG,Guelph, Canada 2Biodome de Montreal, Canada

Every aspect of captive animal stewardship depends on the appropriate formulation and presentation of nutrition to ensure the health and welfare of zoo animals. Providing the appropriate nutrition to animals held in zoological institutions is an international concern requiring the cooperation of zoological communities around the world. To facilitate this cooperation, an electronic database of zoo animal diets has been created by the Canadian Association of Zoos and Aquariums Nutrition Advisory and Research Group (CAZA-NARG). The Comparative Nutrition Database© (CND©) is a free, web-based resource of diets proven to maintain the health and reproductive success of animals held in zoological institutions around the world. For each diet, the CND© provides information on the submitting institution, diet ingredients and amounts, commercial suppliers, a nutritional analysis and, specific notes on the presentation of the diets. The CND© is available on the CAZA-NARG website ( and it is hosted by the Biodome de Montreal. Diet submission is a continual process as is diet revision. Participation in the CND© requires submission of diets to CAZA-NARG and, if the submitting institution cannot provide a nutrient analysis, CAZA-NARG will try to provide that analysis. Each participating zoological institution will receive a unique password to access the CND© that will allow them to edit previous submissions. In addition, each institution will receive a password that allows “read-only” access to all their employees. Academic institutions affiliated with participating zoological institutions will receive their own, unique “read-only” password. The compilation and provision of the CND© will help all zoological professionals maintain and increase the welfare of captive animals by providing diets historically successful in maintaining the health and reproductive abilities of those animals within our stewardship. Such a database will also address those animal nutrition issues that result from limited manpower within advisory organizations and will aid zoological professionals in their growth and learning of animal nutrition. Using the CND© as a teaching tool within zoological and academic institutions will also increase the welfare of animals within our stewardship. Present plans include incorporation of the CND© in the ZIMS project with formatting to link animals to ZIMS by ISIS numbers. The presentation of this paper will include a demonstration of the CND©.

Foundation and function of EAZA Nutrition Group (ENG), providing specialist support for European conservation breeding programmes

A.L. Fidgett1, P. Bircher2, W. Janssen3 and J. Nijboer3

1North of England Zoological Society, Chester Zoo, Chester, Cheshire, CH2 1LH, UK; 2Marwell Preservation Trust, Colden Common, Winchester, SO21 1JH, UK;, 3European Zoo Nutrition Centre, P.O. Box 20164, 1000 HD Amsterdam, The Netherlands.

Specialist subject advisors (e.g. veterinary, scientific) are increasingly being added to steering committees for zoo-based conservation breeding programmes worldwide; several advisors in nutrition have already been informally appointed within European programmes. Following the lead of AZA Nutrition Advisory Group, the newly inaugurated EAZA Nutrition Group (ENG) seeks to facilitate improved communication and coordination among nutritionists and those requiring nutrition information, chiefly within zoological institutions. A principal responsibility of the ENG and all its’ members will be providing nutrition advice to zoo-based conservation breeding programmes, and developing guidelines and protocols for general use. ENG will support existing nutrition advisors and recruit, screen, appoint and support additional advisors as requested by individual conservation breeding programmes. To achieve this, ENG must define who can act as an advisor and what the position entails. AZA’s Nutrition Advisory Group have already established guidelines for nutrition advisors, clearly outlining their responsibilities and their material has been used as a template, adapted to best suit European requirements. A unique relationship has been forged with the European Zoo Nutrition Centre (EZNC) based in EAZA’s executive offices, through their assistance in administration duties relating to nutrition advisors.

Spectral Wildlife Nutrition DataBase for plant and animal materials (using visible and near-infrared spectroscopy)

C.W. Yang1, E. Dierenfeld2, S. Chen3, C. R. Hurburgh4

1Animal Nutrition, Taipei Zoo, Taipei, TAIWAN, 2 Department of Animal Health and Nutrition, Saint Louis Zoo, St. Louis, MO, USA, 3 Beijing Zoo, Beijing, CHINA, 4Grain Quality Laboratory, Iowa State University, Ames, IA, USA.

The spectral wildlife nutrition databases (SWNDB) were initially developed using a library of stored samples from the Saint Louis, Taipei and Beijing zoos that had been collected and analyzed through conventional methods over the past 17 years. These samples were used for calibrating and developing VIS-NIR (NIRSystems 6500, Perten and ASD) analysis for known chemical constituents (proximate as well as mineral and vitamin data) at the Grain Quality Laboratory, Iowa State University, Ames, Iowa, USA. The samples included: Plants (Browses, Leaves, Lichens, Bark, Stems, Fruit, Grass, Roots and Pellets), Soils, Feces, Fish, Meat, and a Miscellaneous category. Currently, the database contains over 1500 samples of foods eaten by a variety of species including pandas, gorillas, tigers, snow leopards, hornbills, and lizards, collected from both the wild and as well as captive diets. These data will contribute to an Internet-based, searchable database envisioned both for identification and quantitative proposes. Two primary databases have been developed for calibration that contained 229 plant materials and 103 animal materials. Results comparing three methods of analysis (PLS, ANN and SVM) for crude protein have r2 = 0.994, 0.87 and 0.855, respectively, for plant materials, and r2 = 0.988, 0.917 and 0.846 for animal materials. VIS-NIR analysis is rapid, not destructive of sample, and can provide accurate results for efficient analysis of a variety of foods, both in the lab and in the field.

Poster: What you see is what you get?

Hay quality in Dutch Zoos

F. van Pagée1, P.Viergever1, W.L.Jansen2, J.Nijboer2, D.Kuiper1, T.R.Huisman1

1Dept of Animal Management, Van Hall Instituut, Leeuwarden, The Netherlands, 2European Zoo Nutrition Centre, Amsterdam, The Netherlands

Since hay is the main component in most diets for captive herbivores it is important to know its nutritional quality. Zoos do not produce their own hay and have therefore probably less insight in its quality than for instance livestock farmers who produce themselves.
In October 2003 ten Dutch zoos were visited. In each zoo the person responsible for nutrition was interviewed with the aid of an extensive questionnaire. Questions were asked about the origin of supplied hay, quality control procedures and use of hay in zoo diets.
In each zoo samples (19 in all zoos together) were taken for ‘visual’ assessment and chemical analysis. From each sample a photo was taken.
Hay chemical composition was not known. The participating zoos only practised visual judging on the supplied hay. The ‘sensual’ indicators used by all zoos to grade hay are colour, odour and presence of mould. Stage of maturity was seldom considered and leafiness never. Main quality problems mentioned were mould, dust and palatability but these problems did not occur often.
The ‘visual’ assessment of the samples was done with the help of a standardized form.
Assessment of the samples showed that the majority (12) was in a full bloom stage or beyond. The leaf proportion of most samples was below average. Only three samples were graded as good hay, six were graded as poor hay.
The same samples were chemically tested on dry matter, ash, ADL, ADF, NDF, crude protein, magnesium, calcium and phosphorus.
Crude protein content was in average lower than values given in the Dutch feeding table and by NRC. Fibre content was higher than average, especially ADL and ADF content. Also mineral contents were low. These results are an indicator for a late maturity stage. Quite often hay from land where little or no fertilisers were applied was used by zoos. These samples showed very low calcium and phosphorus values.
There was a direct relation between ‘visual’ assessment and chemical composition. Samples which scored below average in the ‘visual’ test had also below standard chemical values. Samples which were graded as good hay had a good nutritional value.
Based on this it can be recommended to put some effort in training zoo employees in ‘visual’ assessment of hay . This can help in more accurately estimating feeding values.

Poster: Compiling a multimedia database of browse species for herbivorous reptiles

L. Stevenson, A.L. Fidgett, K. Buley1 and D. Sheriff1

North of England Zoological Society, Chester Zoo, United Kingdom; 1Co-chairs, UK Herp TAG.

Most zoos recognise that fresh browse is a beneficial, if not essential, component of successful husbandry of herbivorous mammals, although supply is usually limited by the cost and effort involved obtaining it. The term ‘browse’ can include shrubs, trees, woody vines and stems and also refers to various plant parts - leaves, twigs, shoots, flowers, flower buds and fruits -, and use within zoos is not just limited to mammalian herbivores. However the majority of literature describing browse databases, identifying species and aspects of their suitability for feeding, is limited to these consumers. In 2004 the UK Herp Taxon Advisory Group held a workshop to record and share excellent working practice in reptile nutrition in general, and herbivorous species (mainly terrestrial tortoises and some lizards) in particular. The aim was to describe both the nutritional objectives for optimum diets (e.g. low in fermentable sugars, high in fibre) and also suggest suitable herbaceous ingredients by which this could be achieved. From the list compiled, plants were then classified according to whether they were staple or occasionally used ingredients. To augment the selection of green leafy vegetables that are commercially available, many species of outdoor plants are harvested opportunistically or deliberately propagated. Not only are such species (e.g. dandelion, clover, thistle) nutritionally superior, they add diversity to the diet with potential for physiological and behavioural benefits. However the use of a wider range of plants such as those listed is limited by a lack of knowledge and a means of identifying which species are safe. To counteract this, we describe a database incorporating photographs, scientific and common names of ‘native’ plant species, together with nutritional analyses of selected material harvested locally.

Poster: Continuing global synergy through nutrition training & outreach activities

E.S. Dierenfeld1, C.W. Yang2

1Department of Animal Health and Nutrition, St. Louis Zoo, USA, 2Animal Nutrition, Taipei Zoo, Taiwan.

The past 5 years have resulted in rewarding recognition and considerable growth of interest in nutrition as a scientific discipline essential for zoo animal management, realized on global scale. In addition to continuing increased membership in the AZA’s Nutrition Advisory Group, both the European (EAZA) and Canadian (CAZA) zoo associations have formally initiated nutrition interest groups, and an informal group has been formed within the Colombian zoo association (ACOPAZOA). Latin American growth was jump-started by a training grant awarded through the Columbus Zoo, TACA airlines, and other sponsors to support development of 3 Colombian zoo professionals selected through the Zoo Conservation Outreach Group in 2001. As part of their training program, these individuals reviewed and translated jointly-developed training materials into Spanish (available at As follow-up and continuation of the outreach activities, they organized nutrition workshops in-country, support joint food composition as well as diet databases locally, and continue to pursue research topics in comparative nutrition. More recently, the Southeast Asian Zoo Association (SEAZA) supported training workshops in Thailand (2002) and Indonesia (2003); individuals were identified as central contact personnel, and databases of local food composition and diets are being complied for Internet dissemination. The South Asian Zoo Association for Regional Cooperation (SAZARC), with support from a University Federation for Animal Welfare grant and the World Zoo Association, targeted nutrition training as a priority for its participants in 2003 meeting, held in Sri Lanka. Working Groups highlighted topics in Herbivore, Carnivore, Avian/Reptile, and Primate nutrition areas to better describe, identify, and share information on the composition of local feedstuffs, successful diets and hand-rearing protocols. Follow-up of nutrition goals and objectives was the focus of the 2004 SAZARC meeting in Pakistan. Also in 2004, the Chinese Association of Zoological Gardens (CAZG) organized a 3-day training workshop hosted by the Beijing Zoo, attended by almost 70 zoo professionals, and representing more than 35 facilities. One result of that workshop will be the translation of Zootrition software into a Chinese language version. Lastly, following a nutrition workshop at the Johannesburg Zoo in 2004, a wider-ranging workshop is planned for South African zoos in March 2005. Identifying and communicating local needs, wants, and interests provide the foundation; providing basic educational tools and materials with which to develop local resources – both personnel and information – is the key to full expansion.