One Holstein bull, Pawnee Farm Arlinda Chief (Chief), has cost the dairy industry millions, recent research from US has shown.
Research shows that the bull carried a defect on chromosome five, which resulted in reduced conception rates in Holstein cattle.
The defect, which can be traced back to a single bull born in 1962, became prevalent worldwide as Chief sired more than 16,000 daughters, 500,000 granddaughters and over 2m great granddaughters.
Across the US and worldwide, the bull was extremely popular among breeders and his genetics can currently be found in 14% of Holstein DNA.
The mutation has caused an estimated 525,000 spontaneous abortions worldwide over the past 35 years, accounting for almost €400m in losses, researchers from the University of Illinois have shown.
According to the researchers, fertility is one of the most important traits determining the sustainability of animal agriculture.
For example, the milk produced as a result of a successful pregnancy and the number of complete gestations in a cow’s lifetime are essential to maintaining the profitability of a modern dairy operation.
If reproductive performance decreases, it says, financial losses accrue because of reduced milk production of the herd and the need for replacement animals to maintain herd size.
But despite the €400m loss associated with Chief's defective genes, researchers estimated that his influence on the dairy industry worldwide is worth close on €28 billion in extra milk production.
And despite the disastrous effects associated with the bull, research has shown that the prevalence of the mutation has decreased due to selective breeding.
In past decades, the carrier frequency of the fatal gene stood at 8%, but this has reduced to just 2% in 2015, it shows.