Mutation in Dairy Cattle Causes High Milk Yield and Embryonic Death

Scientists from Aarhus University and partners discovered a mutation in dairy cattle which both causes a positive and a negative effect at the same time.

Scandinavian dairy cattle's' milk production has been found to increase significantly for the past years. This was attributed to the targeted breeding programs and modern breeding methods. However, despite such efforts no improvements were observed to the cattle's fertility. The genomic deletion reported explains this negative correlation between milk production and fertility. According to Goutam Sahana, leader of the study, the deletion involves four genes and is a recessive embryonically lethal mutation. Thus, the calves die while they are still embryos and are aborted as insemination failure. Both parents must carry the four genes and pass the genes to their progenies for them to be affected.

The mutation has become relatively widespread because of its favorable effect on milk production. By selecting for high milk yields, breeders have unintentionally also selected for embryo mortality.

Read the original article in Danish at research article at http://dca.au.dk/aktuelt/nyheder/vis/artikel/vigtig-mutation-opdaget-i-malkekvaeg/. The research article is published at http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004049.