BILLINGS, Mont. (AP) - The state of Montana is preparing to test certain Wyoming cattle for brucellosis at auction yards, now that the U.S. Department of Agriculture is revoking Wyoming's brucellosis-free status.

State Veterinarian Dr. Thomas Linfield said Tuesday the testing order may be issued this week "to allow the auction markets and the veterinarians to get ready."

Linfield said veterinarians at livestock auction markets would do an onsite, rapid-detection test. Animals testing positive would be quarantined at the sale yard while blood samples went to the Veterinary Diagnostic Laboratory in Bozeman for verification.

Wyoming will lose its brucellosis-free status because the disease has been found in two infected herds of cattle in the state.

Officials in both states estimate the cost of the initial testing at about $5 a head.

To help with part of that cost, the House Agriculture Committee of the Wyoming Legislature on Tuesday passed a bill to appropriate $1.6 million to compensate ranchers for the cost of testing the target animals, said Jim Magagna, executive vice president of the Wyoming Stock Growers Association.

Linfield said all female beef cattle over 24 months old, coming from Wyoming to Montana, would be tested as would all dairy females over 20 months. Any cow in its third trimester of pregnancy would be tested along with any female that fell under the age restrictions and already had a calf.

For bison, non-vaccinated females 12 months or older and all vaccinated females would be tested. The testing requirements apply to such animals that are sexually intact. All intact males, cattle or bison that are more than 12 months old must be tested, Linfield said.

Wyoming can regain its brucellosis-free status if the state has no new cases of brucellosis in cattle for one year.

AP-WS-02-18-04 1039EST