An international collaboration known as the '1000 Bull Genomes Project' aims to accelerate breeding for desired traits in beef and dairy cattle while also improving animal health and welfare. Results of the project's first phase -- based on sequencing the whole genomes of 234 individual bulls whose direct descendants number in the tens of millions -- are reported in the journal Nature Genetics.
According to the researchers, breeding programs could use this information to reduce or eliminate hereditary diseases and to improve the efficency of milk and beef production.
The bulls whose genomes have been sequenced and analyzed represent four of the most commercially important cattle breeds. Scientists from the Technische Universitt Mnchen (TUM) contributed data on 43 sires of the Fleckvieh breed, which has spread to every continent from its origin in the Bavarian Alps. The estimated worldwide population of Fleckvieh dairy cows is 40 million. From the widely distributed Holstein-Friesian population, the collaborators obtained whole-genome sequences for 129 bulls with more than six million daughters on dairy farms. The Jersey breed was represented by data from 15 bulls. Previously published genome sequences for 47 Angus cattle were also integrated into the analysis.
Modern breeding practices, together with advances in genome sequencing technology and bioinformatics, have made better prediction of inherited traits not only attainable but also cost-effective on the basis of a relatively small number of individuals. Selection of sires in cattle breeding is intense, and widespread use of artificial insemination means it's not unusual for a hundred thousand animals to be descendants of a single bull. With the ancestors' sequences , breeders now have a leverage tool in hand that allows them to extrapolate the sequence information to the numerous descendants using readily available chip-based DNA microarrays.
|Contact: Ruedi Fries|
Technische Universitaet Muenchen