Holstein UK – For thousands of years dairy farmers have bred their best cows to the best bulls to ensure the next generation of cattle produce more milk, higher fat and protein or better legs, feet, udders or frames.
Now, though, there’s a new criteria that farmers can select for – immunity. Thanks to research in Canada at the University of Guelph farmers will be able to choose sires that have a higher natural level of disease resistance – which the bulls can pass on to their progeny in the same way as they do with other inherited traits. The heritability of the immune response is similar to that for milk production at around 25%, and is much higher than most other traits associated with health or fertility. Semex will launch a range of proven and genomic sires identified as having high immunity under a new Immunity+ brand from the December proofs. The company says that the new technology “marks a significant breakthrough in improving disease resistance in cattle which will reduce the use of remedial medication”.
At the core of this latest genetic breakthrough is High Immune Response (HIR) technology, which identifies cows with different levels of immune response to diseases such as mastitis, metritis, ketosis, retained placenta and Johne’s diseases. Researchers found that High Immune Responder cows (HIRs) have disease levels that are two to four times lower than those that are Low Immune Responders (LIRs), with the HIRs cows requiring less therapeutic intervention as a result.
Around 10% of bulls are believed to have genes to be classed as HIRs. HIRs have a “more balanced immune response capable of defending the cow against a more diverse range of pathogens”, according to Dr Bonnie Mallard, Professor of Immunogenetics at Guelph, who spearheaded the research.
Testing of the animals takes place over two weeks with the animals being immunised in a similar way to a vaccination to stimulate the immune system. Then blood samples and skin thickness tests are taken, with the patented HIR technology then determining the strength of the immune response. An animal only needs to be tested once to determine its genetic immunity level. The results allow Semex to determine the highest HIR sires.
Cows and bulls can be tested, although in the UK the technology will only be available through the Immunity+ sires. The test is unique to Semex for the next decade as the company has invested several hundreds of thousands of dollars in the research in return for the exclusivity.
“Semex is a technology-driven genetic company and our philosophy is to invest in research and development to improve dairy cow performance and sustainabilty,” says Semex UK’s managing director Gordon Miller.
“High Immune Response technology is another major technological breakthrough after sexed semen and genomics. It marks a significant breakthrough in improving disease resistance in cattle which will reduce the use of remedial medication, and will have a significant effect on dairy cow health and well-being.”
Further news on how Semex will apply the technology for the benefit of farmers will be announced shortly.
