Ian McDonald

Project: GnRH constructs for oral delivery: affects on immune responses and reproductive function

My project aims to determine the efficacy of oral delivery of constructs of GnRH using rats as a model. The two main objectives are to assess the immunogenicity of GnRH constructs when delivered intranasally or orally, and determine if this immune response affects reproductive function

Fertility control has the potential to offer benign, long-term, humane approaches to managing the impacts of overabundant wildlife populations. Contraception methods are considered an ethically more acceptable alternative to culling or translocation when dealing with population control of large mammals, particularly for overabundant native species such as kangaroos.

Current fertility control techniques require the capture and treatment of individual animals which can be stressful for the animals during the capture process and expensive when used on large populations (example: kangaroo populations). For practical use an orally delivered form of fertility control which could be applied strategically to populations in the wild would have broader application and the potential for reducing overabundant wildlife in specific areas.

Results from a GnRH injectable vaccine trial have been promising in reducing fertility in both males and females of a range of mammal species. The GnRH vaccine induces the development of antibodies to GnRH and thereafter disrupts reproduction in both sexes. The duration of the effect is often correlated with circulating antibody titres.

The initial experiments for this project will assess the immune responses to a range of constructs of GnRH delivered orally to lab rats. A range of protein and/or carbohydrate and lipid constructs which have been designed to stimulate immune responses when given orally, will be tested. Those constructs which induce a significant immune response will then be assessed for their effects on reproductive function.

Papers and Presentations

• McDonald, I (2009). Fertility control in macropods – effects on behaviour and welfare. Oral paper at Australian College of Veterinary Scientists Science Week, Gold Coast International Hotel, Gold Coast, Queensland.
• McDonald, I., Murray, P., Phillips, C., Tribe, A., Hinds, L (2009). Immunocontraception – potential for fertility control in macropods? Oral Paper at Australasian Regional Association of Zoological Parks and Aquaria (ARAZPA) Conference, Sea World, Gold Coast, Queensland. Pp 1 – 7 (Paper published online).
• McDonald, I., Tribe, A., Murray P., Phillips, C (2008). Behavioural and welfare impacts of reproductive management in a population of Eastern Grey Kangaroos (Macropus giganteus). Poster presentation at 42nd Congress of the International Society for Applied Ethology (ISAE), Dublin, Ireland. Pg 160 (Abstract published online)
• McDonald, I., Tribe, A., Murray P., Phillips, C (2008). Behavioural and welfare effects of the population management plan of Eastern Grey Kangaroos (Macropus giganteus) at the ‘Pines’ Golf Course Sanctuary Cove. Paper presented at the 6th International Conference on Fertility Control in Wildlife, York, UK. Pg 46 (Abstract published online)