Crushside genotyping in beef on our doorstep

Crushside genotyping in beef on our doorstep


Australia's guru in the application of genomic technologies to beef cattle breeding Prof Ben Hayes.

Australia's guru in the application of genomic technologies to beef cattle breeding Prof Ben Hayes.

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Genomics guru Prof Ben Hayes on what modern science is serving beef.

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IMAGINE a scenario where you take a tail hair from each animal as it comes down the race, put in through a palm-sized device capable of reading DNA markers and by the time that animal reaches the crush you have on your laptop a good indication of what its genes are capable of.

The decision on whether to keep her as a breeder, invest in feeding her or send her off to slaughter can be made both on-the-spot and with confidence.

This is not futuristic fantasising. It’s what modern genetics science is serving up right now.

Crushside genotyping using a genome sequencer could be at a farm near you any day now, says Australia’s beef genomics guru Professor Ben Hayes, from the University of Queensland.

Speaking at a recent conference in Brisbane organised by the Australian Registered Cattle Breeders Association, Prof Hayes said crushside genotyping would open the way to rapid, accurate selection decisions in beef breeding.

RELATED READING: How to get more money for your cattle.

Another of his exciting messages was that genomic breeding values for new traits like heat tolerance in beef was definitely possible.

As the push to improve eating quality ramps up, deciding which bulls to send north was presenting the quandary of balancing meat quality traits with the ability to cope and produce progeny that would cope, Prof Hayes explained.

Heat stress was just one challenge but it was one where genomics could certainly play a big role.

Prof Hayes outlined the experience of Australia’s dairy industry, where scientists were able to put good data sets to use to work out whether individual animals were heat tolerant or not.

“The national database of milk records meant we knew how much milk cows produced on multiple days across their lactation and we also had extensive weather station data reasonably close to every farm,” Prof Hayes said.

“So we were able to link milk production data with temperature and humidity data to work out whether individual animals were heat tolerant or not.

“If we define as our trait how sharply production drops off with temperature and humidity increase, the heritability is about 10 per cent.”

A validation study demonstrated if producers select on the heat tolerance genomic breeding value, that is precisely what they get.

It involved researchers screening 400 heifers about to calve with the DNA markers and predicting their genomic breeding value for heat tolerance.

“We then purchased the 24 most heat tolerant and the 24 most heat susceptible heifers and put them in climate control chambers at 30 degrees with 50pc humidity - moderately stressful - while they were milking.

“The production decline was indeed much greater for the heat susceptible group.”

Prof Hayes said it would be ‘potentially even easier’ to come up with a genomic breeding value for heat tolerance in beef because the core temperature in animals could now be measured.

Meanwhile, fertility in northern cattle was also a good candidate for genomics, Prof Hayes said.

“In northern beef production systems fertility is the driver of profitability but it is a challenging trait to measure in extensive systems,” he said.

It was now clear the path to accurate breeding values based on a DNA marker test capable of “doing a really good job of predicting the value of a bull’s genetics and the fertility of his daughters” would require putting together very large reference sets where we have cows measured for their fertility and also genotyped as well.

That would come via producers doing a great job of recording and putting the data through Breedplan, Prof Hayes said.

The story Crushside genotyping in beef on our doorstep first appeared on Farm Online.

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