DNA analysis has found the cause of the rare disorder that stops some young cattle from the Fleckvieh breed gaining weight, despite normal feed intake. The scientists say that understanding the precise genetic cause could now help to prevent the disorder.
The brown and white Fleckvieh is one of the four major cattle breeds, with an estimated 40 million head worldwide. Because artificial insemination is now the main mode of cattle breeding, a single breeding bull can generate over a 100,000 progeny. This means individual animals within current populations are closely related, allowing recessive traits and disorders to easily spread. Two breeding animals carrying the recessive traits results in a calf with the growth disorder.
"The affected calves and young animals exhibit significantly stunted development in comparison with their healthy contemporaries, despite normal feed intake – growing at roughly half the pace and gaining only half the weight. Apart from that, though, they look completely healthy," said Dr Hubert Pausch from TUM’s chair of animal breeding.
Researchers examined bovine genotypes for specific genetic features that can indicate diseases. They discovered four regions of the genome that have a negative impact on reproductive and rearing success – and animals homozygous for one of them were significantly stunted in growth.
With the aid of comprehensive genome sequencing analysis, the researchers were then able to identify the genetic mutation responsible for this growth disorder.
Scientists say genotyping breeding animals could help avoid the condition spreading. "This would mean problematic matings could be avoided in the future – particularly since certain widely used bulls are genetic disease carriers," said Pausch. "This would enable faster achievement of desired breeding results and prevent many genetic disorders."