Sunday, July 3, 2022

LIC bulls carrying dwarf gene

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The discovery of a recessive gene in top LIC bulls has the company’s genetics in the spotlight again.

After fending off flak last year for its handling of the “hairy calf” gene, LIC has announced the discovery of a recessive gene causing small calves in some of its top bulls.

These include the top sire in LIC’s premier sires Kiwicross team, Howies Checkpoint.

But the company is not alone in carrying the gene within its bull team. The recessive gene has also been identified in some of the bulls of competing firm CRV Ambreed.

Dairy breeders have reported calves with dwarf-like characteristics, including short legs, wide heads and pot bellies and an inability to grow normally.

However, LIC has pointed to reports from farmers over the past 10-15 years about smaller-than-normal calves being born. It estimates it has received up to 20 such calls over that time.

LIC’s genomics research had enabled the gene to be identified, he said.

But coming after LIC’s refusal to compensate farmers left out of pocket by the “hairy calf” gene, and it shelling out $4.7 million for the failure of genomics to deliver promised gains, the company faces some criticism over this latest genetic issue.

Lincoln University associate professor in agriculture and life sciences Jon Hickford said given problems LIC had experienced with genomics and the hairy calf saga, another issue around genetic traits could lead farmers to be suspicious of genetic evaluation.

This could lead them to discount the Breeding Worth (BW) system, he said.

“And that would be a problem for the industry as a whole.”

Federated Farmers dairy chairman Willy Leferink said he hoped LIC would handle issues arising from the gene discovery better than it did the hairy calf saga.

“My hope is this time if they have a case to answer they will do,” Leferink said.

Breeders are concerned about the scale of the gene’s presence, in light of the LIC carrier bulls contributing 450,000 inseminations out of LIC’s four million last spring.

Howies Checkpoint alone contributed 250,000 inseminations. 

Matings between cows carrying the recessive gene to sire bulls also carrying it would result in 25% of calves born having the dwarf trait, or about 7000 calves next spring. These would be predominately Friesian and cross-bred herds.

Estimates are 120,000 calves would also be born carriers as a result of matings with the bulls.

On average 15% of cows in the herd population are carriers of the gene.

LIC’s general manager of research and development Dr Richard Spelman said the gene’s discovery had been confirmed only in the past two weeks, after several years of genetic research.

But the presence of a “dwarf” gene, categorised as the PRKG2 gene mutation for dwarfism, has been recognised by American Angus cattle breeders since September 2007. It presents with similar visual traits in affected animals to the LIC gene.

Spelman said the gene discovered by the LIC research was different to the American one.

The LIC has labelled the gene incidence “small-calf syndrome”.

Spelman said LIC would have a genetic test available for farmers in four to six weeks.

“But 90% of them are very obvious as calves.”

In the meantime LIC intends to screen all its bulls for the gene and use software to give an alert over future carrier-carrier matings. Ultimately the company aims to manage the trait out of herds.

But a long-time breeder told The New Zealand Farmers Weekly he believed the sheer number of inseminations by carrier bulls meant it would be impossible to breed the trait out of the national herd.

He estimated he had 70 cows in calf to Howies Checkpoint this year and averages suggested he could expect at least two affected heifer calves next spring attributable to that one bull.

An LIC spokeswoman said over the years a number of recessive genes have been discovered and the rate of negative and positive genetic variations would only speed up with genomic technology.

 “No genetics organisation in the world could or would predict or guarantee against any of them,” she said.

Spelman said more discoveries would unfold over time and there were genetic companies around the world that would not go looking for such genes in the first place.

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Related stories: Door open to eradicating small-calf geneLIC finds small-calf gene

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