D. Smit1, K.Kool1, J. Nijboer2, W.L. Jansen3, B. van Wijk1 and T.R.Huisman1

1Van Hall Institute, P.O. Box 1528, 9801 BV Leeuwarden, The Netherlands; 2Biological and Veterinary Department Rotterdam Zoo, 3000 AM Rotterdam, The Netherlands; 3Department of Nutrition, Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80152, 3508 TD Utrecht, The Netherlands

Browse (branches, twigs and leaves of woody plant species) are an important component of many zoo diets in The Netherlands. However not much data is available on the actual use of this type of feed nor on its specific nutritional and other properties. To compile an inventory of the current use of browse in Dutch zoos and to get more insight in possible proble ms related to the feeding of these products 10 zoos were visited and in each zoo an extensive interview took place with the person responsible for zoo nutrition. In the 10 zoos a total of 29 (browse) plant genera are used in the various diets. Three plant genera (oak (Quercus spp), willow (Salix spp) and birch (Betula spp.)) were used in all zoos. Ten plant genera are used as browse in only one zoo. It is remarkable that only one respondent claimed to be able to identify the browse used on species level. Most of the browse is collected on the zoo’s premises itself or it’s near surroundings. Browse is occasionally also obtained from the municipal botanical department. Only three zoos buy some of the required browse regularly. Browse conserving is not practised often. This implies that most of the browse is fed during late spring, summer and early autumn, which implies that rations differ between seasons. Where conserving takes place, freezing is the most important method. A few zoos reported that they have attempted to dry browse but due to climatic conditions and/or lack of experience with this process this proved to be rather unsuccessful. Reasons mentioned for feeding browse were: its palatability, use as environmental enrichment and its nutritional value. Although all respondents stated the nutritional value as an important reason to feed browse, the composition of the browse was determined in only one zoo by sending it to a laboratory. Two zoos indicated that (estimated) nutritional values of browse were used in diet calculation. Eight zoos stated that they would like to have more information on nutritional values of browse or its possible alternatives. Most zoos have a preference for willow spp. as browse. This preference is not based on any knowledge of the nutritional composition of willow but mainly on the (assumed) positive experience of other zoos and its availability. Also its palatability is an important aspect. In connection with browse the respondents mentioned the following problems: lack of (regular) availability, insufficient and inadequate storage facilities and lack of nutritional data. Six or more of the zoos indicated to be interested in the results of research on the following subjects: nutritional composition of browse (10/10), the possibilities to replace browse by other products (9/10), factors influencing the nutritional composition (7/10), effects of secondary plant components (7/10), browse as an indispensable component of the rations (6/10).


E. Torvinen

Ranua Zoo, Rovariiementie 29, 97777 Ranua, Finland

Ranua Zoo is located very far in north (just 80 km south of the Arctic Circle), so we work in an area where the reindeers also live in wild. Actually the reindeers are not wild animals, but they spent most of their life in wild, up in north most of the year, but in this area the keepers take most of the animals in enclosures for the coldest part of winter (from January to April). In the whole Finnish Lapland we have about 200 000 reindeers (and 200 000 people, so everybody has one reindeer!) and they produce 2 000 000 kg of reindeer meat every year. In many zoos people have had problems in feeding captive reindeers, but here up in north its not a problem. In wild the reindeers have big seasonal changes in their nutrition. The metabolic level is in winter 45% lower than in summer. Also the plants they eat are very different in winter and in summer. In summer they use green plants; grass, many different species of plants, leaves of trees (Betula, Sorbus and Salix species). In winter they prefer lichens (Cladonia and Cladine species) and also arboreal lichen. In southern Lapland they also eat Dechampsia flexuosa and some other grass and brushwood (Vaccinium and Erica). Whenever possible, the lichens make even 50-60% of the food in winter. Nowadays in many areas there is no longer enough lichen available. Thus in many areas the keepers also use pellets for feeding the reindeer in wintertime in addition to dry hay and dried leaves. In our zoo we try to follow the seasonal changes as much as possible. In summer we feed the reindeers with green grass and green leaves. They also get some pellets - the idea being that they are allowed to eat as much as they want. In autumn they eat lots of mushrooms in wild and so we offer mushrooms also for our animals. They also get vegetables or fruits in September/October. When the winter starts and snow comes, the reindeer start to get lichens and the winter diet includes pellets, lichen, dried hay and leaves. So in winter the diet is of much poorer nutritional quality than in summer. One important thing is to take care of the parasite-problem. The reindeers are very sensitive to parasites, so the medical care of parasites throughout the year is important.


P. Wolf1*, N. Kummerfeld2 and J. Kamphues 1

1Institute of Animal Nutrition and 2Clinic for Pet and Wild Birds, Hanover School of Veterinary Medicine, Bischofsholer Damm 15, D-30173 Hannover.

Keeping of emus (Dromaius novaehollandiae) and rheas (Rhea americana) under european environmental conditions is discussed frequently. The local climate and available areas for grazing and moving activities don´t favour the keeping of such birds originated from South America (rhea) or Australia (emu) under local conditions. Furthermore there are risks for animals´ well-being due to the lack of experiences as well as due to the fact that species-specific complete diets are not available continuously. Therefore home-mixed diets are fed, that are often unbalanced and leads occasionally to nutritional disorders of skeleton. In the following case reports those problems caused by faults in feeding and mineral supply are described. Case 1: Due to a supply shortage an owner of a small zoo fed emus a home-mixed diet (ingredients: pelleted diets for piglets as well as for rabbits, mineral product rich in protein, CaCO3). The hatched emu chickens could be adapted very quickly to this diet and showed high growth rates in the first weeks of life. In the age of 3 to 4 weeks 13 of 37 chickens showed a reluctance to rise or move. One week later these chickens showed ataxic moving activities as well as slight thickening of the distal tibiotarsus and proximal tarsometatarsus, that increased in the following 14 days. At the same time the long bones developed rotational deformities (bones turned outwards and caused a „paddling movement“). Nutritional history: In a critical examination of mangers a macroscopic difference between the offered feed (pelleted) and the refusals (white-grey fines) could be observed. Crude fiber and starch of the refusals were lower, but crude ash and calcium contents were higher compared to offered ration. Data of blood chemistry showed slightly lower mineral contents and X-rays underlined the bad posture of the legs. Assessment: Due to the different prepared feedstuffs of the home-mixed ration (pelleted as well as meal) the ingredients of the diet could not be mixed well, so the emus could preferred the pelle ted components (Ca-content in the real intake lower than in the offer; furthermore a protein content of 22% was measured) and refused the mineral supplement. This selective ingesting behaviour, the high growth rate of emu chickens and the insufficient mineralization of skeleton encourages the occurence of the observed clinical signs (perosis). Case 2: 3 of 15 young rheas (3 months) showed unphysiological postures of the necks vertebral column. The „diet“ was based on corn, pelleted alfalfa, apples, lettuce and white bread in he first 8 weeks of life; afterwards a pelleted complete diet was fed. Clinical history: The X-ray of vertebral column showed complete healed up fractures of individual vertebrae. Nutritional history: Before feeding the complete die t the owner observed a selective ingesting of corn and white bread, whereas the other components were refused. The preferred components are characterized by low mineral contents (especially calcium, copper). Assessment: Due to an insufficient mineralization of the skeleton and a high mechanical stress (rough handling to applicate a deworming) fractures of the vertebral column occurred. After feeding the complete diet these fractures healed up due to the better mineral supply of the ingested commercial complete diet.



C.W. Yang

Taipei Zoo, 30 Sec. 2 Hsin Kuang Road, Taipei 11628, Taiwan

Currently the Taipei City Zoo raises 377 types of ungulates, in 11 families, and 44 species. From 1997 on, we adjusted the types of feed and formulations, which began with fresh forage and edible hay. Included were six kinds of fresh grass, branches, and leaves. These are used for the major food for our ungulates, which effectively reduces the undesirable condition of soft excrement, which is often seen with our giraffes before. We experimented with five kinds of imported hay between 1997 and 1999, eventually eliminating all but one type exclusively; the domestically produced Pangola hays ad libitum since October 1999. In light of the damp weather (Monsoon season) at Taipei, especially in wintertime, the hay storehouse is airconditioned and kept at the constant temperature of 16~18°C. Two dehumidifiers are kept on all day to control the relative humidity under 75%. We also increase different alfalfa elements in the feed and bring the content of vitamin E in compound feed from 100 IU/kg to 400 IU/kg. In the instance of our local Formosan serow, we started to increase the supply of compound feed and vitamin E additive to their diet in 1997, and improved the feeding method of branches and leaves. Consequently, there are less episodes of diarrhoea and higher survival rates of young animals in the winter. The serow at the zoo multiplied from 4 in 1997 to 11 in 2000. The numbers of ungulates at the zoo are more than three hundred, so we attempted in May 2000 to add antihelminthic (flubendazole) in the compound pellet feed for parasite control. Numerous Ascaris were purged from our Mongolian wild horses and zebras only one day after administration. The same method (Ivermectin 0.2mg/kg body weight) was used to purge nematode in October 2000, which also provided good effects. In the future as part of our parasite control efforts we will add suitable doses of antihelminthic in the compound feed pellets to address the specific need of certain species.