There were no regulations about the amount of time animals could be in travel, except for young calves.
''The maximum time that an animal can be transported will depend on a number of factors, including the transportation conditions, age and physiological status of the animal being transported,'' Dr Littin said.
MPI had also developed a ''fit for transport'' phone app that gave animal owners, transporters and others guidance in determining whether livestock was fit for transport, she said.
When it came to animals being off feed, it was an issue that needed to be managed carefully to avoid both animal welfare and effluent problems.
The minimum standard in the code of welfare for transport stated that the provision of food and water before transport must be appropriate to the species, age, physical state and condition of the animals to allow them to regulate body temperature and meet their health needs.
Unweaned animals must not go unfed for more than 28 hours before slaughter.
Dr Littin said some example indicators for the maximum time off food included 36 hours for ruminants and 24 hours for pregnant or lactating animals.
These were just indicators and not legally enforceable, she said.
MPI veterinarians monitored the transport of stock by assessing their welfare when the animals arrived at processing plants and before being culled.
''Animal welfare cases are graded depending on severity and are dealt with by education and, where necessary, further investigation and enforcement action,'' Dr Littin said.
''Problems such as overstocking and injury can be picked up at these inspections.''
MPI also monitors the transportation of livestock at other steps along the supply chain, including farms and saleyards.
Overall, it was the responsibility of all of those in charge of animals to look after their welfare, Dr Littin said.
''Farmers, transporters and others need to be aware of, and follow, requirements for transport.
''Farmers should be aware of the destination of their animals and communicate with transport operators to ensure the welfare of the animals is maintained.
''The code of welfare for transport addresses monitoring and responding to incidents during transport.''
Southern Rural Life