A rare bovine disease, called Bovine Johne's Disease (BJD), has been detected among a number of cattle herd in Central Queensland. But an agriculture lobby group had maintained the beef from the concerned state remains safe to eat as BJD cannot affect humans.

Still, Biosecurity Queensland had placed on alert more than 100 cattle producers after the discovery of the BJD in a Rockhampton herd.

Biosecurity officers are now tracing the "substantial numbers" of cattle that moved from the Kirk family's Rockley Red Brahman Stud at Bajool near Rockhampton to find out how far the disease may have spread. Its three other properties near Moura were likewise isolated.

One of central Queensland's best known and respected Red Brahman studs, the Rockleyis regularly featured among the top prices at the annual Rockhampton Brahman Week bull sales.

BJD, defined as a wasting disease that can cause emaciation and death in cattle, poses no risk however to human health. But rural lobby group AgForce said the disease cannot affect humans. It only has a one per cent mortality rate in cattle.

In spite of the current outbreak, Howard Smith, Agforce Cattle Board president, said he remains confident it will not largely hurt the cattle industry in the state.

"The safety of eating beef and associated products will not be impacted," he said in a statement.

"It is important to note BJD is present in most of the countries Australia trades with and should not place the Queensland industry at any commercial disadvantage."

But initial findings of the Biosecurity Queensland reveal the Rockhampton stud herd appeared to have been infected for many years, according to a report by the Beef Central, although the infection's original source still remains unidentified.

"These movements are being traced and risk assessments will be undertaken to determine the potential spread of disease," Biosecurity Queensland said in a statement.