Elephant Nutrition in Dutch Zoos
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Elephant nutrition in Dutch zoos Ingrid van Baarlen Mercedes Gerritsen Elephant nutrition in Dutch zoos An inventory of the diets of the African elephant (Loxodonta africana) and the Asian elephant (Elephas maximus) in Dutch zoos Leeuwarden, February 2012 Authors Ingrid van Baarlen Mercedes Gerritsen Supervisors Tjalling Huisman & Corine Oomkes Initiation NVD Nutritional Group Dr. Joeke Nijboer Keywords African elephant, Loxodonta africana, Asian elephant, Elephas maximus, nutrition, diets, health problems Van Hall Larenstein project number 594000 Pictures on the cover Ingrid van Baarlen Preface This report was written in the scope of the final thesis project of the study Animal Management at Van Hall Larenstein in Leeuwarden, The Netherlands. Both of us choose the major Wildlife Management, with a module on animal nutrition. Elephants are a difficult species to keep in zoos when it comes to all aspects of husbandry, and especially nutrition. Over the past few years, elephants have therefore been the centre of attention and a lot of focus has been put on correct elephant husbandry and nutrition. In light of this fact, several reports have been written, with the BIAZA 2010 [Walter, 2010] report on elephant husbandry being the most recent, that want to help contribute to improving elephant keeping. This project, an initiative of dr. J. Nijboer of Rotterdam Zoo and the NVD Nutritional Group, is therefore the start of a European-wide inquiry into the elephant diets to investigate if these comply to the nutritional requirements as described in literature. We chose this study as our thesis project because we both would like to contribute to the improvement of elephant health and because of our growing interest in zoo nutrition. We would like to thank everybody that helped us during this study, especially our supervisors T.R. Huisman and C. Oomkes from Van Hall Larenstein for their guidance, support, and commentating on the manuscript. We would also like to thank the following zoos for responding to our online survey: - Natura Artis Magistra Amsterdam - Burger’s Zoo Arnhem - Diergaarde Blijdorp Rotterdam - Dierenpark Amersfoort Amersfoort - Dierenpark Emmen Emmen - Dierenrijk Europa Mierlo - Ouwehands Dierenpark Rhenen - Safaripark Beekse Bergen Hilvarenbeek We hope this report will mark the start towards an inquiry into the health and nutrition of European zoo elephants. Ingrid van Baarlen Mercedes Gerritsen Leeuwarden, Februari 2012 Summary There is no clear overview of the current dietary practices and problems with regard to elephants within Dutch and Belgian zoos, so to be able to assess whether zoos comply with current requirements. The goal of this study was to gain insight in the present feeding practices of the African (Loxodonta africana) and Asian (Elephas maximus) elephants held in Dutch and Belgian zoos and to compare these to the current dietary ex-situ requirements for elephants. Elephant are hindgut fermenters with a low digestive efficiency. Their natural diets vary enormously and are of low quality. The low digestive efficiency and low feed quality result in a high forage and feeding time of 15-18 hours a day. Their diet in captivity, however, is relatively high in quality with a high energy and sugar content compared to the natural diet. Products like fruit, concentrates and bread lead to the high energy and sugar content. Obesity can be a result of this and is therefore a major problem among captive elephants. Other nutrition related health problems include foot problems, vitamin E deficiency, colic and hypocalcaemia. To gain insight into the current feeding practices, 11 online survey questionnaires were sent out to Dutch and Belgian zoos holding elephants. The surveys contain questions about the animals, their diets, their body condition and their health. The results from the surveys’ dietary questions were analysed by calculating the nutritional value (energy, dry matter and nutrients) of all the ingredient used in the diets. These results were then used to calculate the nutritional value of the diet per animal per day on a dry matter basis. Of the 11 zoos that received the survey, 8 zoos replied. All 8 of these zoos were Dutch and this resulted in a 100% response rate from the Netherlands and 0% from Belgium. The results show that a wide range of ingredients used in elephant diets, though there are six most commonly used, namely: grass hay, apple, concentrates, carrots, bread, and willow branches (in that order). All these ingredients were supplied in widely differing amounts in the various zoos, with differences of up to 59kg (grass hay). There were 12 different diets in total: in some cases males and females are housed separately, and two zoos alternate between grass hay and fresh grass at different times of the year. The results show that the roughage contained the highest proportion of most nutrients, with the exception of vitamin E and biotin. The calculation of the average amount of energy offered by the zoos shows that none of the diets complied with the average MMR per animal. All diets are either too rich (7) or deficient (5) in the amount of energy. However, the calculation of the MMR did not take the age, sex or life stage of the elephants into consideration. The calculated total nutritional composition shows major fluctuations between zoos in the total amount of ingredients, dry matter and energy, with one zoo (zoo 8) feeding significantly less than other zoos. The nutrient composition of the diets is similar, however , with the exception of the vitamin E and biotin levels, which do show major differences. The conclusion that can be drawn from the results is that most diets do not differ extensively from the requirements, but that there are large exceptions. Zoo 8 showed a few major deficiencies when compared to the requirements. Three other concerns include the calcium, phosphorus and vitamin E content. All three of these nutrients could have a serious effect on the health of the elephants when fed in incorrect amounts. Zoos should monitor the health and weight of their elephants on a regular basis using either a weigh-bridge or Body Condition Scoring method. Also, zoos should keep good records of the ingredient amounts, changes in feeding behaviour of the animals and weight changes. Finally. roughage should be analysed on a regular basis so concentrates and supplements can be fed accordingly. To be able to gain valuable and usable results for a diet study, it is necessary to let zoos know the importance of good record keeping and how data should be supplied. Also, if zoos are open to the idea, personal visits could be a possibility if time allows. Table of contents 1. Introduction ...................................................................................................................... 8 1.1 Objective .................................................................................................................... 10 1.2 Research questions .................................................................................................... 10 1.3 Definitions ................................................................................................................. 10 1.4 Research population .................................................................................................. 11 2. Methodology ................................................................................................................... 12 2.1 Method of data collection .......................................................................................... 12 2.1.1 Literature review ......................................................................................................................... 12 2.1.2 Survey ......................................................................................................................................... 13 2.2 Processing and analysis of the data .......................................................................... 15 3. Literature review ............................................................................................................ 22 3.1 General information .................................................................................................. 22 3.1.1 Population numbers .................................................................................................................... 22 3.1.2 Taxonomy ................................................................................................................................... 22 3.1.4 Animal biology ........................................................................................................................... 24 3.1.5 Anatomy and physiology of the digestive tract........................................................................... 27 3.2 Wild situation ............................................................................................................. 29 3.2.1 Habitat description ...................................................................................................................... 29 3.2.2 Foraging behaviour ..................................................................................................................... 34 3.2.3 In-situ diet composition .............................................................................................................. 36 3.3 Captive situation in zoos............................................................................................ 46 3.3.1 Diet in