Mortality and morbidity risk factors for livestock during sea transport from Australia

Summary

Although the veterinarians and stockmen described their findings as they considered appropriate, there was substantial variation in the scope and detail provided in the mortality reports examined. For example, one report consisted of two pages of text with statements such as Shorthorn cattle were sometimes affected by the heat. Conversely, another report contained a reasonable description of the gross findings for each necropsy together with objective assessments of some of the health conditions affecting the cattle. Such a variation between reports makes interpretation of findings and comparisons between voyages very difficult for others.

The reports indicate that Bos taurus breeds are struggling to cope with the hot humid conditions encountered during sea transport. Clinical signs of heat stress were observed, and death from heat stress was diagnosed. However, further investigation is needed to determine whether there are differences in breed susceptibility to heat stress. A useful parameter to measure could be respiratory rate. Although poor ventilation was frequently considered to predispose to heat stress, it was recognised that the problem is multi-factorial. Except in cases of extremely high temperature and relative humidity, it was considered that temperature and relative humidity were less important than air flow.

There is a need to define the minimum ventilation standards required for cattle during sea transport and to ensure that ships meet such standards, particularly when carrying Bos taurus breeds from southern ports during the Australian winter. It may be useful to examine research findings from the North American cattle industry or from the pig and poultry industries. On one ship the same deck was identified as a problem area on separate voyages. This vessel has a poor record on other voyages. Further investigation of the ship is needed, and appropriate prevention strategies should be implemented before the onset of the northern hemisphere summer.

There are serious animal welfare problems involved during discharge at Egypt. The imposition of a curfew on feed and water exposes the industry to another mortality incident, particularly during hot weather. Immediate action is required to resolve this problem. Unloading facilities at Egypt are inadequate to handle the cattle in a manner that does not increase the risk of injuries or death. Consideration should be given to the design and use of an unloading trailer such as the MOVOR that was deployed at various Gulf ports for unloading sheep from Australia. There is a need to improve quality control of the cattle exported. Improved procedures are needed to ensure that cattle in an advanced stage of pregnancy are not exported. Cattle should be within importers specifications, particularly for age, thus avoiding the need for restraint and examination of individual animals before discharge.