Four cattle markets in northern Nigeria, where stolen animals were allegedly being sold to finance the Boko Haram Islamist insurgency, have been shut down.
Insurgents are using unscrupulous middlemen to sell stolen cattle, the governor of Borno state said.
Trade was suspended about two weeks ago at Gamboru cattle market - one of the biggest in Africa.
Boko Haram has stolen thousands of cattle in Nigeria and nearby Cameroon.
The group's six-year insurgency has led to the deaths of some 17,000 people, destroyed some 1,000 schools and displaced more than two million people.
The suspension of the cattle trade has affected businesses in a region already battered by Boko Haram's deadly campaign to establish an Islamic state.
Much of Nigeria's cattle trade passes through Borno and the closures have reportedly caused cattle prices to rise in Lagos, more than 1,500km (940 miles) away.
A civil-military management team has been set up to monitor the activities of cattle traders and butchers in order to stop all illegal activities, Borno Governor Kashim Shettima said in a statement.
All transactions must be vetted and approved by the new team, he added.
Cattle markets in Dusuman, Shuwari and Ngom have also been suspended. The insurgency had already forced the closure of other markets in Borno's capital, Maiduguri.
The government has also suspended all cattle imports and banned the sale of dry meat.
Thousands of cattle and goats are dying from lack of water and food after being locked in at the main abattoir in Maiduguri, Abubakar Abba of the Livestock Traders' Union told the Associated Press news agency.
Correspondents say the militants, who have pledged allegiance to the so-called Islamic State group, are in dire need of food after regional troops cut off their supply lines.
The group has also lost most of the territory it once controlled but still carries out frequent suicide attacks in northern Nigeria and Cameroon.
Boko Haram at a glance:
- Founded in 2002, initially focused on opposing Western-style education - Boko Haram means "Western education is forbidden" in the Hausa language
- Launched military operations in 2009
- Thousands killed, mostly in north-eastern Nigeria, hundreds abducted, including at least 200 schoolgirls
- Joined so-called Islamic State, now calls itself IS's "West African province"
- Seized large area in north-east, where it declared caliphate
- Regional force has retaken most territory this year