Thursday, June 18, 2009

Radical New Genetic Pathways to Change Livestock Breeding

It seems as if Australian science has delivered another major advance in agriculture, this time in the methodology of livestock breeding. It could have very important ramifications for almost all livestock groups, but especially cattle. Now a driver in dairy cow improvement, it is coming to beef production soon.

And so far, once again, other parts of the world have been quick to implement it's use.........with Australia lagging behind.............AGAIN!

Genetic breakthrough to change livestock breeding

WHEN Mike Goddard reflects on the path that led him into livestock genetics the response takes time.
"It seemed like a fun topic."

It is an incongruous reply for a Melbourne born and bred man who has dedicated himself over the best part of 40 odd years to improving methods for genetic selection, but one Professor Goddard has never seen as a disadvantage.

But taking Professor Goddard's modesty aside (when asked his reaction to a recent honourary doctorate awarded by the Norwegian University of Life Science he said "it was nice") Australia's and the world's advancement in livestock genetics has been a slow and often lonely road.

"We have been trying to use genetic markers since about 1990 but it is only in recent years that it has started to take off," he said. "The technology was never quite been good enough and in fact a lot of people gave up."
So where are we at now, and just what role does Australia play?

Questions Professor Goddard takes great pride in answering.

In terms of the future, he says genetics is about to take off - the technology is working and the world's need to produce more food from less has governments seeking solutions.

The dairy industry in the United States has started using a new Single Nucleotide Polymorphism (SNP) chip that can test 50,000 gene markers at once, and New Zealand, Holland and Australia are following closely. "This means instead of having to wait five years while a bull's progeny are tested, producers can test for DNA markers when the bull is born, and when the bull is a year old and semen available it can be used."

With this science, Professor Goddard said there is the potential to double the rate of genetic gain.

As far as Australia's role in genetic advancement, considering its size "we have been at the forefront in livestock all along".

"If you were to nominate one scientific area where Australia contributes more to world knowledge than expected from its population size, it would be in genetic improvement of livestock," he said.

In 2001 Professor Goddard and his colleague Ben Hayes authored a paper that showed how to predict the total genetic value of an animal using genome-wide dense DNA markers. This work, the Meuwissen, Hayes and Goddard paper, widely revered in genetic communities as breakthrough science, has since become proven thanks to the commercial release of a SNP chip for cattle in 2004.

The ability to track tens of thousands of genes in the one test, as predicted by Professor Goddard and his colleagues, has opened the flood gates on the potential for rapid genetic gain, and word travelled quickly. In the world's leading genetic early adoption country, the United States, 4500 progeny-tested dairy bulls have been tested and thousands more are scheduled. In Australia where Professor Goddard admits it has been an "unfortunately slower" around 2000 dairy bulls have been tested.

For beef and sheep, DNA testing is not a new concept, but Professor Goddard says we can't yet predict genetic merit in beef and sheep as accurately as in dairy cattle. "In dairy there is not the multiple breed problems - if it works in Holstein that is three quarters of the job done."

What Professor Goddard and his colleagues are aiming for is a commercial arrangement with a DNA company such as Pfizer, but to retain a centralised common estimated breeding value database from which producers can benchmark stock.

"For years it has been relatively easy to find the gene for traits that are controlled by a single gene such red coat color, but many traits are controlled by lots of genes which each have a small effect so the advantage with the SNP chip is that we can test up to 50,000 markers all at once."

Beef will be next to follow the dairy lead, and sheep after that, he says.

Professor Goddard, a former tropical livestock genetics expert at James Cook University Townsville, has acquired an international reputation for his broad grasp on livestock genetics.

His passport wears the mismatched marks of a seasoned traveller who is regularly fronting international genetics conventions, and in Australia his unique skill set has him stretched across duties within the Melbourne University, Department of Primary Industries and Beef CRC - as a start.

His professional career has coincided with the livestock genetics movement.

It began as a young veterinary graduate, in the 1970s, when he completed his PhD on a breeding program for guide dogs for the blind at University of Melbourne. It was working with the genetics/breeding scheme of dogs that Professor Goddard's unfaltering intrigue in genetic possibilities started. Livestock, he said, was just the next natural step.

Looking back he said it is difficult to conceptualise that a lot of the work has only just started to eventuate, but he has no doubt that genomic selection will spawn a whole new way of selecting animals.

Already he said work is being done in the beef and dairy industries on identifying genes for feed conversion traits, and in time there is the hope that producers and processors will be able to test livestock and decide for which market the animal would be best suited. "Gradually genetic selection will be introduced into all livestock sections and it will revolutionise them."

"This I have no doubt of."

extract from Queensland Country Life 18 June 2009

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