(1) All M-branded, Mx-branded, and other cattle or bison two months of age and older originating directly from Mexico (imported into the U.S. within 60 days) require two negative TB tests 60-120 days apart. The first negative test can be the U.S. entry test. The second negative TB test must be performed by a USDA-APHIS VS accredited veterinarian and must be within 60 days prior to importation into Montana.