Biosecurity strategies for conserving valuable livestock genetic resources.

The foot and mouth disease (FMD) epidemic in the UK in 2001 highlighted the threat of infectious diseases to rare and valuable livestock and stimulated a renewed interest in biosecurity and conservation. However, not all diseases resemble FMD: their transmission routes and pathological effects vary greatly, so biosecurity strategies must take this into account. Realism is also needed as to which diseases to exclude and which will have to be tolerated. The aim should be to minimise disease generally and to exclude those diseases that threaten the existence of livestock or preclude their national or international movement. Achieving this requires a team effort, bearing in mind the livestock species involved, the farming system ('open' or 'closed') and the premises. Effective biosecurity demands that practically every aspect of farm life is controlled, including movements of people, vehicles, equipment, food, manure, animal carcasses and wildlife. Above all, biosecurity strategies must cover the disease risks associated with moving the livestock themselves and this will require quarantine if adult or juvenile animals are imported into the herd or flock. The present paper emphasises the important role that reproductive technologies, such as artificial insemination and embryo transfer, can have in biosecurity strategies because they offer much safer ways for getting new genetic materials into herds/flocks than bringing in live animals. Embryo transfer is especially safe when the sanitary protocols promoted by the International Embryo Transfer Society and advocated by the Office International des Epizooties (the 'World Organisation for Animal Health') are used. Embryo transfer can also allow the full genetic complement to be salvaged from infected animals. Cryobanking of genetic materials, especially embryos, is another valuable biosecurity strategy because it enables their storage for conservation in the face of contingencies, such as epidemic disease and other catastrophes.