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9.6 Port of loading
The database recorded the port of loading for all voyages. Ports were classified into a three level categorical variable as follows:
North-west: all ports in Western Australia north of Geraldton and including Dampier, Port Hedland, Broome, Wyndham and Darwin;
South: all ports from Geraldton south and around to South Australia and Tasmania and including Geraldton, Fremantle, Bunbury, Esperance, Portland, Adelaide, Geelong and
Devonport; and Other: all ports in Queensland and New South Wales and including Mourilyan, Weipa,
Karumba, Townsville, Mackay, Gladstone, Brisbane, Port Kembla, Newcastle, Sydney and any ports that were not able to be identified.
Figure 19 shows mortality rate by load port region within Australia and destination region, for voyages to MENA and SE Asia only.
Figure 19: Mean mortality rate by load port region within Australia and destination region, for voyages to MENA and SE Asia only 1995-2012. Bars represent 95 confidence intervals. Data
derived from all years combined.
Mortality rates for cattle loaded in the north and going to MENA or SE Asia were significantly lower than mortality rates for cattle loaded in the south and going to the same destination
region p0.001.
For cattle loaded in the south, the mortality rate for voyages to SE Asia was significantly higher than the mortality rate for voyages going to MENA p=0.008. There was no
.0 5
.1 .1
5 .2
.2 5
.3 .3
5 .4
South North
Other
Load region in Australia
MENA SE ASIA
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difference in mortality rate by destination MENA vs SE Asia for cattle loaded in the north p=0.2.
The finding that adjusted mortality rates deaths per 1,000 cattle-days were higher for southern cattle going to SE Asia than for southern cattle going to MENA was unexpected.
Further analyses were conducted, using data subsets representing the two more recent time periods.
Figure 20 shows mean mortality rate by load port region within Australia and destination region, for voyages to MENA and SE Asia only and where the data were limited to the period
from 2003-2012 only. This was done to use more recent data to explore possible explanations for higher mortality risk in voyages travelling to SE Asia.
Figure 20: Mean mortality rate by load port region within Australia and destination region, for voyages to MENA and SE Asia only. Bars represent 95 confidence intervals. Data restricted
to 2003-2012.
When the effects of load port and destination were assessed using only the data from 2003- 2012, there was no difference in mortality rate for cattle loaded in southern ports and going
to MENA vs those loaded in southern ports and going to SE Asia p=0.3. There was also no difference for cattle loaded in northern ports and going to MENA compared to SE Asia
p=0.6.
For voyages to MENA, there was a tendency for southern loaded cattle to have a higher mortality rate than northern loaded cattle p=0.053. For voyages to SE Asia, southern
loaded cattle had a higher mortality rate than northern loaded cattle p0.001.
.0 5
.1 .1
5 .2
.2 5
.3 .3
5 .4
South North
Other
Load region in Australia
MENA SE ASIA
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Further comparisons were then performed on the mean mortality estimates by load port and destination region for 2010-2012 Figure 21.
Figure 21: Mean mortality rate by load port region within Australia and destination region, for voyages to MENA and SE Asia only. Bars represent 95 confidence intervals. Data restricted
to 2010-2012.
There was no difference in mortality rate for cattle going to MENA if they were loaded in northern vs southern ports p=0.9.
For cattle going to SE Asia, the mortality rate for cattle loaded in the south was higher than the mortality rate for cattle loaded in the north p=0.006.
There was no difference in mortality rate for cattle loaded in southern ports and heading to MENA vs SE Asia p=0.8.
For cattle loaded in the north, voyages travelling to MENA had a higher mortality rate than voyages going to SE Asia p=0.01.
This was explored further by fitting a model that included season Summer, Autumn, Winter, Spring; Figures 22 and 23.
Figure 22 shows mean mortality rate by load port region within Australia South vs North and season of departure, for voyages to MENA only and limited to 2010-2012. Figure 23
shows similar data, but for voyages to SE Asia only and limited to 2010-2012.
.0 5
.1 .1
5 .2
.2 5
.3 .3
5 .4
South North
Other
Load region in Australia
MENA SE ASIA
Page 129 of 201 Figure 22: Mean mortality rate by load port region within Australia South vs North and
season of departure, for voyages to MENA only. Bars represent 95 confidence intervals. Data restricted to 2010-2012.
Figure 23: Mean mortality rate by load port region within Australia South vs North and season of departure, for voyages to SE Asia only. Bars represent 95 confidence intervals.
Data restricted to 2010-2012.
The most interesting finding is seen in Figure 23 for SE Asia voyages where voyages were recorded in all seasons from both north and south ports of loading. The elevated mortality
risk in Summer appears to be limited to cattle loaded in southern ports, whereas there is little seasonal change in mortality risk for those cattle loaded in northern ports. It is not possible to
.0 2
5 .0
5 .0
7 5
.1 .1
2 5
.1 5
.1 7
5 .2
.2 2
5 .2
5
Summer Autumn
Winter Spring
Season
South North
Voyages to MENA only, from 2010-2012
.0 2
5 .0
5 .0
7 5
.1 .1
2 5
.1 5
.1 7
5 .2
.2 2
5 .2
5
Summer Autumn
Winter Spring
Season
South North
Voyages to SE ASIA only, from 2010-2012
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explore these associations for voyages to the Middle East and North Africa, because most voyages to these destinations were loaded in southern ports. Voyages from northern ports
were only recorded during Winter and Spring.
The same general pattern was seen for southern loaded cattle in both destination groups, in that Summer voyages had a higher mortality rate than voyages in other seasons.
In summary, the findings indicate that there has been a progressive reduction over time in mortality rate, best viewed by looking at long term plots of mortality rate by year from 1995 to
2012.
More detailed assessment is limited to the most recent time period 2010-2012 since this is likely to best reflect current performance and practices.
Monthly patterns indicate a rise in mortality rate during Summer months and a decline in Winter months. The Summer rise is most prominent for voyages to MENA and much less
prominent for voyages to SE Asia. There was a small but significant Winter rise in mortality for voyages to MENA that was not apparent for voyages to SE Asia.
There was an effect of port of loading which may be a proxy for cattle species. Our ability to explore this effect was limited because voyages to MENA did not have any cattle loaded in
the north during Summer and Autumn, and because we were not able to collect detailed information on species of cattle in this project. Our results do indicate that for SE Asian
voyages, the Summer peak in mortality appears to be driven by cattle loaded in the south and there was no real change in mortality rate through the year for cattle loaded in the north.
Southern loaded cattle show the same Summer peak for voyages to MENA.
Other sources have reported that cattle loaded from northern ports are more likely to be Bos indicus genotype than Bos taurus.
68
Cattle loaded in the north are also considered more likely to have been raised in the north and may have more exposure and adaptation to
northern climatic extremes including higher temperatures and humidity. Cattle loaded in the south may be more difficult to characterise. Southern cattle may be mathematically more
likely to include temperate genotypes such as Bos taurus than tropically adapted genotypes such as Bos indicus, however we would expect there to be more diversity in the south and
also it is considered more likely that some cattle loaded in the south may have originated from northern properties, whereas it may be less likely for cattle loaded in the north to have
originated from southern properties. It would be of value to the industry to have breed and other relevant potential risk factors recorded as a routine in industry datasets to facilitate
better use of statistical analyses to understand risk and inform risk management.
Norris et al
69
have reported that Bos indicus cattle had lower mortality percentages than Bos taurus cattle in their study.
It seems plausible that the elevated mortality rate in our study for cattle loaded in the south during Summer may be due in part to genotype, as well as other factors such as seasonal
voyage conditions.
68
DAFWA 2009
69
Norris et al. 2003
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It is our understanding that voyages to NE Asia and SE Europe may be more likely to include breeder cattle than voyages to MENA and SE Asia. Anecdotal information suggests
that breeder cattle may be more valuable than feederslaughter cattle and may be managed differently during a voyage for example lower stocking density and different bedding and
perhaps different preparations including pre-export treatments and vaccinations. We did not have detailed data on animal type breeder vs slaughter or feeder animal and we had
relatively less data on voyages to SE Europe and NE Asia, so we were not able to characterise mortality rates for these destination areas with the same detail. Further work is
needed to describe mortality rate patterns for these areas and to understand drivers.
There appears to be some level of uncertainty over the possible role of season in mortality risk in land-based feedlot cattle. Seasonal variation in mortality in feedlot cattle is well
described with peak mortality occurring in Autumn and Winter in some studies
70
and in Spring-Summer in others.
71
A recent survey of Australian feedlots reported that the seasonal pattern of mortality risk over the course of a 12-month period appeared to be
related more to incoming numbers of cattle density and time post feedlot induction and less related to seasonal effects per se.
72
The combined effects of northern monsoon rainfall that limit the ability of northern producers to muster and transport cattle during the wet, summer months, and seasonal constraints for
southern cattle due to ASEL restricting exports of Bos taurus cattle between May and October, are likely to contribute to an increased number of Bos taurus cattle being exported
from southern ports between November and April.
Figure 24 shows monthly total cattle numbers loaded for export from northern or southern ports, for voyages to SE Asia only and for the period 2010-2012. Figure 24 is consistent with
the hypothesised description of factors modifying numbers of cattle exported. Relatively more cattle were loaded from southern ports in January and February, than in all other
months, and relatively fewer cattle were loaded from northern ports in these months.
70
Loneragan et al. 2001; Ribble et al. 1995
71
Babcock et al. 2013
72
Perkins 2013
Page 132 of 201 Figure 24: Plot of monthly total cattle numbers loaded for export from northern or southern
ports, for voyages to SE Asia only and for the period 2010-2012.
20 40
60 80
1 1
2 1
4
1 2
3 4
5 6
7 8
9 10
11 12
Month Loaded in south
Loaded in north
Voyages to SE Asia, 2010-2012
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Figure 25 shows monthly total cattle numbers loaded for export from northern or southern ports, for voyages to MENA only and for the period 2010-2012.
Figure 25: Plot of monthly total cattle numbers loaded for export from northern or southern ports, for voyages to MENA only and for the period 2010-2012.
The pattern for southern ports is consistent with a large increase in cattle exported in Summer and this increase may be sufficient for disease risk to be increased due to animal
density and co-mingling and other related factors that are independent of season per se. These findings stimulate questions about whether the apparent seasonal pattern in mortality
rate may be explained in part by factors associated with animal density stress, co-mingling, exposure risk, etc rather than direct season effects associated with changes in
environmental or climatic factors. These same issues are topical in understanding seasonal patterns in land-based feedlot mortality risk and there is evidence suggesting that seasonal
changes in animal density may be exerting a bigger effect on mortality risk than seasonal climatic variation.
73
Further work is needed to explore this issue. The pattern for northern exports to SE Asia is bimodal with peaks in April-May and
September, perhaps coinciding with first and second round musters. It is also apparent that cattle exports from the north continue all year round so the seasonal conditions may impede,
however they do not prevent cattle aggregation and transport during the wet season.
It is more difficult to explain the pattern for exports to MENA. Cattle loaded in southern ports appear to peak at February, July and October. It is not clear what may be influencing the
variation in numbers. There are too few data points for northern cattle to the MENA for a pattern to be appreciated. The results appear to support a hypothesis that MENA markets
73
Ibid.
10 20
30 40
50
1 2
3 4
5 6
7 8
9 10
11 12
Month Loaded in south
Loaded in north
Voyages to MENA, 2010-2012
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may prefer cattle from southern ports, perhaps because of a preference for Bos taurus genotypes.
9.7 Daily voyage mortality
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