VDS conducts Trichomoniasis testing via polymerase chain reaction (PCR). 

From the New Mexico Livestock Board website:

Bovine Trichomoniasis- The New Mexico Livestock Board has implemented regulations to protect producers from this highly infectious, contagious disease. Rules adopted are consistent with other state regulations governing this disease.

Effective immediately, Bovine Trichomoniasis testing will be done using polymerase chain reaction (PCR) technology.  This change will result in greater sensitivity and specificity for overall increased test accuracy.  Handling of preputial samples, transport, collection techniques, etc., can compromise the quality of the sample using traditional culturing technique.  Traditional culturing methodology:  does not detect dead parasites, only identifies the presence of Trichomonas, and does not differentiate between T. foetus and other species of Trichomonas.  Because PCR technology is DNA based, this methodology can detect infection that has been missed by traditional cultural technology because of very low organism numbers or dead/dying (in transit) organisms.  However, accuracy of test results using PCR may be compromised if the sample is received more than 3 days after collection.  With increased accuracy, some increased expense is incurred.