Farmers can be confident of the M.bovis free status of World Wide Sires’ bulls thanks to one of the most exhaustive processing, testing and treatment regimes in the world.
The company sells more than 19m straws of semen annually to 90 countries around the world and, over several decades, has developed semen production and processing procedures which are amongst the most rigorous in the world; procedures verified and endorsed by the US AI industry standards organization NAAB (National Association of Animal Breeders).
These standards were developed, several decades ago, as a response to frustration at the varying standards of laboratories and their inability to grow and culture mycoplasma compounded by long interval before results could be assessed by culture.
Around seven years we were fortunate to come into contact with Dr Kristina McDonald, a microbiologist of some renown, who wanted to make the identification of M.bovis the central theme of her PhD as that is one of the more pathogenic strains of microplasma. Select Sires (our parent company) sponsored her research.
Dr McDonald’s PhD made use of modern PCR based techniques to detect mycoplasma bovis in semen. She developed efficient methods for growth, culture, DNA extraction, and PCR based detection.
No evidence of mycroplasma bovis was found in any of Select Sires’ 1700 bull team either during the research programme, or since.
The extender World Wide Sires uses for frozen semen is made from homogenized, pasteurised whole milk and glycerol. Antibiotics - including Gentamicin, Tylosin, Lincomycin, and Spectinomycin - provide a secondary line of defense against seminal contamination as well as primary action against mycoplasma, ureaplasma, and Haemophilus somnus.
Notwithstanding the results of Dr McDonald’s research, following the outbreak of M.bovis on several Canterbury dairy farms, World Wide Sires commissioned testing of semen from bulls sold in that region - from two independent laboratories around the world.
This semen was sent fresh without any additives or antibiotics to Cornell University in the USA and to MPI labs in Wallaceville New Zealand. No evidence of M.bovis was found.