ANGUS Australia is calling for all members to report any calves born dead and malformed following the indefinite discovery of a recessive gene in an American super sire.
The American Angus Association recorded 48 calves born dead with a twisted spine and lacking muscle development - characteristics consistent with Curly Calf Syndrome - over a 10 day period in mid-September.
The syndrome is likely caused by a recessive gene tentatively traced from the most recent common ancestor on both sides of the pedigree of affected calves, GAR Precision 1680.
Not all GAR Precision 1680 progeny will carry the gene; in the case of a trait with simple recessive mode of inheritance there is a 50 per cent chance a resulting calf will be a carrier when both parents are carriers while about 25pc will be affected and 25pc will be non carriers.
When one parent is a carrier and the other a non carrier, about half the calves born will be carriers the other half non carriers.
Angus Australia’s breed development and information manager Carel Teseling said users of the Precision 1680 bloodline should react cautiously to this news.
“When only one parent is a carrier about 50pc of the s progeny are suspected to be carriers while 50pc should be free. There are a lot of good genetics out there not carrying the defect that are still very valuable,” Mr Teseling said.
Carriers are not affected and can be used in a breeding program with caution, especially when a DNA test becomes available.
But, according Mr Teseling, the development of such a test will take time and requires large amounts of funding and data.
“We currently are dealing with a very small number of cases, both here and in the States, considering the widespread use of this bloodline,” he said.
“We need three categories of samples to develop a DNA test; animals we are 100 per cent sure don’t carry the gene, ones we are sure do and affected calves. They (the American Angus Society) will need all affected calves to be reported so they can take a sample for this research.”
Such a DNA test would be very useful to the commercial industry where pedigrees aren’t always known or easily found out.
In the seedstock industry it is possible to breed around the problem by using pedigree information to ensure possible animal carriers are not present on both sides of the pedigree.
“This test would not be developed solely for the seedstock industry where the pedigree is known on both sides. We are looking for a solution for the commercial industry – a test where even those bulls that have the bloodline are proven free of the defect and can be sold and used with confidence.”
Mr Teseling said the test would also allow breeders with a cow herd with the bloodline to determine carriers and join accordingly.
“Some people may choose not to get rid of all carrier animals – the genetic value of an animal for some production traits may be just too superior. In these instances individual breeders will have to determine the level of risk they are prepared to take.”
Angus Australia has so far received only three reports of possible curly calves and, as the reports are very recent, none of these have yet been parent verified.
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