Research projects


Fertility and aggression control in male animals through GnRH vaccination


Prof. Henk Bertschinger (University of Pretoria, South Africa)
Prof. G.van der Horst (University of the Western Cape, South Africa)
African Elephant Research Unit (AERU)
Knysna Elephant Park, South Africa
African Lion Safari, ON, Kanada
Wuppertal Zoo, Germany


South Africa, Canada, Europe


GEOlifes and partner currently test the application of a “chemical castration” in male animals (e. g. elephants and several ungulate species) through the application of a vaccine designed against the endogenous hormone GnRH (gonadotropin releasing hormone). With a vaccination against GnRH, the bodies´ own hormone will be neutralized by the immune system of the animal. Therefore, the production of testosterone is stopped without surgical removal of testicles.
Ultrasound of the reproductive tract, semen collection, fecal testosterone measurement and behavioural records will help to evaluate the effectiveness of this simple and non-invasive method.


GEOlifes, International Elephant Foundation (IEF)

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