The export of live animals by air is a very small component of the livestock export industry, accounting for only 0.31% of cattle, 0.26% of sheep and 50.33% of goats exported during 2004-2005. Although mortality rates of livestock during air transport were not recorded until recently, the average mortality rate is extremely low because most livestock that are airfreighted are high-value breeding or slaughter animals. Most livestock consignments are carried in the holds of passenger aircraft. Recently, three major incidents involving excessive mortalities of goats and deer and several "near-incidents" have taken place. The near-incidents involved incompatible aircraft ventilation systems. As the ventilation of aircraft is technically complex and there are no simple guidelines on minimum aircraft ventilation requirements for livestock, exporters may experience difficulty in determining whether ventilation onboard a particular aircraft is suitable for the export of livestock. In many instances, exporters are reliant on recommendations of airline personnel and airport ground staff regarding the ventilation capacities of individual aircraft. Working in conjunction with the LiveAir organisation, the industry initiated a project to produce a readily available and simple guide to assist ground crews, freight forwarders, air crew and exporters to assess the suitability of the various aircraft ventilation systems for specific classes of livestock. Having commenced the project, it became apparent that information on respiratory gas exchange and heat generation of goats and deer was required.