Causes of death in sheep exported live by sea

Abstract

Post-mortem examinations were conducted on 950 dead and terminally ill sheep during assembly for export and during transport by sea from Fremantle, Western Australia to various Middle East ports. Causes of death were grouped into 5 major categories; inanition (deaths associated with reduced feed intake, including hypocalcaemia and hypomagnesaemia), salmonellosis (enteric and septicaemic), trauma, diseases associated with excessive feed intake (lactic acidosis and enterotoxaemia) and miscellaneous diseases (mostly of farm origin). During assembly the causes of death were salmonellosis 53.4%, miscellaneous diseases 23.8%, trauma 12.6%, inanition 10.2%, acidosis 3.9%, enterotoxaemia 3.4% and no diagnosis was made in 3.4%. During shipping the causes of death in defined populations of sheep in 5 voyages were; inanition 43.4%, salmonellosis 20.2%, trauma 10.6%, miscellaneous diseases 5.9%, enterotoxaemia 1.0% and no diagnosis was made in 19.0%. The range of mortality rates per 10,000 sheep at risk for the first 11 days at sea in 5 voyages were inanition 52.6 to 76.7, salmonellosis 7.8 to 109.8, trauma 2.1 to 17.1, miscellaneous diseases 5.9 to 17.1 and enterotoxaemia nil to 10.3.

Cattle deaths during sea transport from Australia

“…This is in stark contrast to the live sheep trade where approximately 75% of all deaths during shipping are associated with failure to eat. 2 This observation suggests that the factors which predispose to inappetance in sheep 5 are of little significance to cattle during sea transport.…”

“…The death rate has been defined, the causes of death established and the main risk factors identified. [1][2][3][4][5] In these studies, analysis of ship Masters' reports was a valuable method of establishing the death rate and identifying some of the risk factors. 1 The present report describes the results of investigations into the deaths of cattle during sea transport from Australia.…”

Salmonellosis in Animals

“…In most countries of the world with a large sheep population, including the UK, Australia, New Zealand and the USA, sheep salmonellosis is apparently rare and does not represent a relevant economic issue. Disease distribution and prevalence of infections due to ubiquitous serovars is typically seasonal and associated with animal movement and shipping [32,33]. Exposition to prolonged environmental stress, including cold, poor nutrition and concurrent diseases, might be important to activate latent infection and Salmonella shedding in faeces [33].…”

“…Examination of slaughter-age healthy sheep and identification of Salmonella species have been often reported in the past few years, due to public health concerns of these serovars entering the human food chain [37]. Ovine salmonellosis might be an important zoonotic reservoir for human infection and a number of studies have reported food-borne transmission to humans [30][31][32][33][34][35][36][37][38][39][40].…”

Behavioral and physiological responses of livestock to simulated and actual transport by sea

“…These long distance journeys are stressful for the animals and create public concern about animal welfare issues (Randall, 1993;Phillips and Santurtun, 2013;Phillips, 2008). In spite of that, the mortality rate, considered the major welfare indicator in the Australian live export trade, has been decreasing from 2.5 % reported in 1980 (Richard et al, 1989) to 0.71% in sheep and 0.10% in cattle in Table 1.Mortality rate in sheep transported overseas from 2010 to 2017.…”