2.88 w liv 0284 review of asel scoping study.
Page 103 of 136
Earlier studies suggested that there may have been inadequate statistical power to identify explanatory factors Norris et al., 1989b. A subsequent study reported spatial clustering with farms
associated with higher mortality risk coming from the south-east region of Western Australia - an area of higher rainfall and longer pasture growing seasons, compared with the more extensive
pastoral areas to the north and east of Perth Higgs et al., 1999.
When these findings are interpreted in association with maps of Australian sheep production zones, it appears reasonable to infer that pastoral sheep may have a lower mortality risk than non-pastoral
sheep. This issue was a major motivation behind the development of the LIVE.123 study which was initiated to provide information on causes of death in live export sheep, to identify factors
contributing to the risk of death, and to determine if the risk of mortality for pastoral and “distance” sheep and lambs during the May to October period was higher than that for other classes of sheep.
The LIVE.123 study was able to document an elevated mortality risk for pastoral sheep in the period from May to October. This was particularly the case for sheep originating from the Broken Hill region
of New South Wales and from Queensland, regardless of whether they were held over in Victoria before preparation in the assembly feedlot Makin et al., 2009.
Sheep sourced from the far west of NSW had the highest mortality with sheep from the former RLPB districts of Milparinka, Broken Hill, Wanaaring and Wilcannia having the highest mortality. The
following table summarises the performance of the NSW pastoral sheep by district Makin, 2010. There were four lines of sheep in the final dataset that were received as pastoral sheep for the
purposes of the trial but their property identification code was not recorded.
Table 6.5: Mortality for NSW pastoral sheep. The table shows district of origin, number of lines from each district, total number of sheep, mortality count and mortality and 95 CI Makin, 2010.
95 CI Former RLPB
District Number of
lines
Sheep Mortality
Count Mortality
Lower Upper
Balranald 5 1,826
9 0.49 0.26
0.93 Bourke 2
1,235 15 1.21
0.74 1.99
Broken Hill 17
6,236 328
5.26 4.73
5.84 Hillston 7
4,839 14 0.29
0.17 0.49
Milparinka 5 4,127
328 7.95 7.16
8.81 Wanaaring 8
4,693 152
3.24 2.77 3.78 Wentworth 2
605 0 0.00 0.00 0.63
Wilcannia 20 11,180
215 1.92 1.68
2.19
Total 66 34,741 1061