Agriculture Victoria has issued a reminder to farmers about their responsibilities when transporting bobby calves.
Officers conduct regular audits of bobby calves at saleyards, calf scales and abattoirs.
Livestock Welfare Compliance program manager Veronica Campbell said authorised officers were still finding unfit calves being supplied for transport and sale.
They'd also discovered over-crowded calf trailers or ones that didn't meet the prescribed requirements.
The mandatory requirements for transporting bobby calves were detailed within the Australian Animal Welfare Standards and Guidelines - Land Transport of Livestock.
Ms Campbell said everyone along the supply chain was responsible for bobby calves, including sellers, buyers, transporters, scale operators, livestock agents and saleyard and abattoir staff.
"Bobby calves that are fit for their intended journey must be healthy and alert," Ms Campbell said.
"They should weigh at least 23 kilograms, be strong, able to bear weight on all four limbs and able to rise from a lying position.
"Their hooves should be firm, and their navels dry, wrinkled, withered and shrivelled."
Ms Campbell said if a calf wasn't fit to load, appropriate arrangements must be made for its care or treatment - "if in doubt, leave it out".
Ms Campbell said calves must be adequately protected from the weather during transport and be kept clean and dry.
Dairy Farmers Victoria president Mark Billing, Colac, said the standards were there - and clear.
"If dairy farmers are not full across the standards, I would recommend they contact department staff to make sure they are meeting the requirements," Mr Billing said.
"It's important all animals we look after are well cared for, whether they are on farm or being transported for sale."
He said there were no excuses but at calving time there was a lot of pressure on the farm.
"Getting bobby calves, off farm for sale, is part of the process but there are a lot of farms rearing their calves, as well."
Poor practices opened the door to animal welfare groups to create trouble, he said.
"One bad apple could cause serious issues for our industry and it's working through alternatives to selling bobby calves; it's not something we are ignoring, right now.
"A lot of time and effort is being spent, right now, in developing further guidelines, on farm, and opportunities to put animals into other than bobby calf markets.
"That won't suit all farms, and we have to be mindful of that."
For further information regarding bobby calf welfare visit the Agriculture Victoria website, call 136 186 or consult with animal health and welfare staff at your local Agriculture Victoria office.
Anyone wishing to make a specific complaint regarding livestock welfare can contact Agriculture Victoria at aw.complaint@agriculture.vic.gov.au or phone 136 186.