Impact of sea transport on animal welfare: Australian case studies (sea transport of sheep and cattle)

摘要

Cattle and sheep are exported from Australia by sea and form a significant market for Australian animals. For instance, in both 2006 and 2007 over half a million cattle were exported by sea from Australia, with the majority travelling the short journey to Indonesia. Other destinations included other Asian countries and the Middle East; about one tenth of the cattle travelled the “long haul” voyages to the Middle East and North Africa (MLA – Livestock Export Market Outlook Reports Dec 07). There are considerably more sheep transported by sea from Australia, with 3-4 million sent in both 2006 and 2007, the majority of these travelling to the Middle East and North Africa. (MLA – Livestock Export Market Outlook Reports Dec 07).ududA number of factors have been identified as impacting on the welfare of animals transported by sea. Norris et al. (2003) identified heat stress as a major cause of reduced welfare and increased mortality of cattle transported by sea, and as an important cause of increased mortality of sheep during periods of extreme hot, humid conditions (Norris and Norman 2002). These findings led to research into the physiology of heat stress in cattle and sheep, with a view to finding ways to ameliorate the effects on the animals, such as the provision of electrolytes.ududIn conjunction with this work, a Heat Stress Risk Management model was developed (Stacey 2003), which used all available data on ships, weather conditions, voyages, and animal factors such as heat stress thresholds for different classes of animals and stocking rate to determine and therefore reduce the risk of a heat stress incident. The heat stress threshold was determined as the prevailing wet bulb temperature at which the animal’s core body temperature was 0.5 °C above what it would normally be, and climate room work was conducted to identify that threshold for various classes of animals commonly transported by sea.