Summary and Implications
Although past research has proven the organism, Tritrichomonas foetus, can survive freezing technologies utilized in the 1950’s, it is unknown if it can survive freezing in liquid nitrogen, the current freezing media for bovine semen. Live organisms were identified after thawing in fiveof the twelve straws evaluated. Between 0.5 and 6 liveorganisms were identified in the samples taken from thesestraws. The number of live organisms within each of these 0.5 mL straws was estimated to be between 25 and 300 live organisms. The ability of T. foetus organisms to survivecurrent freeze-thaw techniques for bovine semen suggeststhat artificial insemination using semen from T. foetus
positive bulls poses a significant risk for spreading thispathogen to other cattle in breeding herds
Iowa State University
Phillips, Patrick E.; Myers, Jacqueline N.; and Dewell, Grant A.
"Viability of Tritrichomonas foetus Following the Freeze-Thaw Cycle Used for Freezing Bovine Semen,"
Animal Industry Report:
AS 662, ASL R3048.
Available at: http://lib.dr.iastate.edu/ans_air/vol662/iss1/9