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Assessing Risk Factors for Reproductive Failure and Associated Welfare Impacts in Elephants in European ZoosReproductive failure in elephants is thought to be caused or influenced by a range of factors such as obesity, infectious disease, husbandry, facilities, stress, behaviour, maternal experience, herd size and social grouping. Due to the low reproductive activity of the small zoo elephant population, scientific study into the relative importance of these factors is limited. This study takes an epidemiological approach using risk analysis methodologies to collate information from expert opinion, data set analysis and a targeted questionnaire to identify and assess a range of physical, behavioural and husbandry based risk factors, which may affect reproductive success in elephants housed in European Zoos. Much of our knowledge on reproduction in zoo elephant populations originates from North America where there are significant differences in herd structure, management practices, climate and mean age. By combining multiple sources of evidence including a large survey of reproduction in the European elephant population and eliciting expert opinion from scientists, zoo managers, veterinarians and keepers working with European zoo elephants in a structured, transparent and scientifically recognised process it has been possible to identify the most important causes of reproductive failure and assess the influence of a range of potential confounding factors. Important causes of reproductive failure included lack of access to a compatible bull, herd stability and compatibility, allomothering or maternal experience, management practices at parturition and the impact of Elephant Endotheliotropic Herpes Virus. This work is to be used in the development of evidence-based elephant management and welfare recommendations and highlights priority areas for further research.
Risk based testing for Mycobacterium bovis following a clinical case in a zoological gardenMycobacterium bovis is a strictly controlled disease. Outbreaks in zoos result in animal movement bans, disease investigation and euthanasia of infected animals. Both specific tuberculosis legislation and European Directive 92/65, often known as the "Balai" directive, require zoos to be free from tuberculosis in order to import and export animals. This paper describes the use of a risk based targeted testing programme for tuberculosis following a confirmed case of disease. This regime ensured a comprehensive but proportionate disease investigation developed through close co-operation with government veterinary officials, therefore limiting the impact of anaesthetic procedures and animal handling required to complete the necessary testing.
Survey of reproduction and calf rearing in Asian and African elephants in European zoosAcyclicity, conception failure, abortion, stillbirth, dystocia, infanticide and neonatal mortality have all been reported as causes of reproductive failure in zoo elephants. These events are often reported as single case reports or in specific studies focused on a particular stage in the reproductive process. In North America wider surveys of reproduction in the zoo elephant population have been completed and repeated to provide data over a number of years. This study is the largest and most comprehensive study of reproduction in the European zoo elephant population to date. Two questionnaires collected data from throughout the reproductive process from assessing cyclicity to independence of the calf at 5 years old. Information was collected regarding 189 birth events. Many causative and contributing factors such as obesity, infectious disease, husbandry, facilities, stress, behaviour, herd size and social grouping have been proposed. The importance of these was assessed and where possible association identified using statistical analysis. In African elephants, this study found that age, obesity, reproductive pathology and dominance, identified as important risk factors for failure to conceive in the American zoo elephant population were of low importance. The most significant cause in Europe was lack of access to a compatible bull. In Asian elephants reproductive failure was much less common but when it did occur age and reproductive pathologies were significant factors as found in previous studies. Previous studies have found that age, obesity and infanticide were considered as the most important risk factors in the period from birth to rearing. In this survey it was found that herd stability and compatibility, allomothering or maternal experience and management at parturition can significantly influence reproductive success. Elephant Endotheliotropic Herpes virus was confirmed as the biggest cause of calf mortality. This work provides evidence to support changes to elephant management in European zoos in order to encourage development of social and affiliative herd behaviours and improve reproductive success.