UK study may boost breeders against recessive genes in livestock

 

 

Scientists could be about to deliver a huge boost to livestock breeders and end the curse of recessive genes that cause inherited syndromes, diseases and deformities in cattle, sheep and pigs.

 

Work at Edinburgh University's Roslin Institute is using the latest DNA technology - homozygosity mapping - to identify problem genes and then develop genetic markers to breed them out. The project - funded by Quality Meat Scotland (QMS) and a wider industry consortium – has been hailed as it should allow scientists to deal with any problem linked to recessive genes far more speedily.

 

Roslin genetic group leader Professor John Woolliams said scientists had up to now been hampered in their efforts to deal with recessive diseases until they became commonplace in many breeds.

 

The new DNA mapping technology, however, takes identification to a new level as it can in a single test pinpoint about 50,000 genotypes compared to the 200 that previous machines delivered.

 

Work elsewhere has already allowed scientists to deal with a crooked tail syndrome in Belgian Blue cattle in the breed's homeland in Belgium. Teams are also working on resolving problems in Italian Chianina cattle that results in calves being born with deformed skin, eyes, ears and mouths. Similar gene work has already led to a DNA test that can be used to avoid Fell pony syndrome, a fatal condition in the foals of Fell and Dales ponies.

 

Woolliams pointed to significant financial benefits from the work as issues could now be dealt with for a handful of thousands of pounds instead of the hundreds of thousands previously. It also meant problems could be identified from as few as 12 animals.

 

Prof Woolliams said scientists were now more likely to take on work as the technology took a lot of the risks out and meant solutions could be found.

 

QMS expert Professor Charlotte Maltin said the work - which also involves the Scottish Agricultural College - would deliver real benefits to the pedigree livestock world as it meant problems caused by recessive genes could be picked up early and resolved speedily before they became a major problem.

 

Recessive genes can be caused by breeds concentrating on too small a gene pool and the limited use of sires.

 

Prof Woolliams highlighted a problem in the Holstein breed that caused bovine leukocyte adhesion deficiency. It was linked to a popular bull called Bell, but finding its defective gene took considerable time and resources as it was done without the current technology.

 

QMS is also funding projects to develop an improved test for Johne's disease in cattle and ensure the better targeting of wormers to avoid any further increase in anthelmintic resistance.

 

It is also used levy cash collected from farmers to fund work to improve meat-eating quality.