subject: DNA sequencing

Genomic Selection Accelerates Improvements in Health and Productivity of Dairy Cows

Genomic Selection Accelerates Improvements in Health and Productivity of Dairy Cows

The introduction of genomic selection into dairy cattle selective breeding programs has been greatly anticipated and is a remarkable example of the benefits of genomic technology. Made possible because the systems for selective breeding were already well developed in dairy, and the widespread use of artificial insemination meant that new developments could be delivered quickly. First introduced in the USA in 2008, there has now been sufficient time to generate enough data to assess its impact. Read More...

Ancient Aurochs Genome Contains the DNA Blueprint for Modern Cattle

Ancient Aurochs Genome Contains the DNA Blueprint for Modern Cattle

A preserved specimen of aurochs bone was discovered deep beneath the Derbyshire Dales in the UK in the 1990s. Aurochs are an ancient cattle breed domesticated around 10,000 years ago somewhere around modern day Iran. In Europe, the last of these animals were still found on a Polish royal reserve as recently as the 17th century. Park et al., have now extracted enough DNA from the ancient bone specimen to sequence the aurochs genome. When they compared the aurochs sequence to the DNA of cattle breeds we know and use in domestic agriculture today, they found a surprisingly high level in common with British and Irish cattle. Read More...

Accounting for Lactase Mutants

Accounting for Lactase Mutants

Back in the 50s and 60s, work on lactose intolerance was often published under cringeworthy and blunt racial titles. A Nature article from 1969 sums it up with ‘Can Asians Digest Milk?’ It was also probably a subliminal non-accident that ‘lactose intolerance’—which is the typical condition for adult humans—became common parlance for a trait for which those with northern European ancestry are the real mutants. Many decades on, the genetic basis of the ability to digest lactose has been largely pinned down. As it turns out, there are different genetic reasons for the mutants’ lactose tolerance in the various populations that drink milk without intestinal incident, and the gene that confers mutant power in Europeans is only part of the story. That research history is discussed below, along with recent work that has extended the field’s reach beyond genetics. Investigations of the transcontinental basis of lactose tolerance are now providing insights into mankind’s cultural, as well as biological evolution. Read More...

The Amazing Mammary Memory

The Amazing Mammary Memory

Any dairy farmer or lactation consultant knows that first-time mothers don’t produce as much milk. The peak daily production for a first calf heifer may be around 70 lbs of milk while the same animal on its second lactation can produce 90 lbs of milk daily. Somehow the mammary gland seems to remember how to make milk and does a better job the second time. Why is that? Read More...

Predicting Performance in Dairy Cows of the Future

Predicting Performance in Dairy Cows of the Future

Selective breeding of dairy cows is a major part of modern dairy farming. Farmers can select the bulls that they want to use to produce animals for their herd. One bull may sire thousands of daughter cows via highly developed systems for artificial insemination. The availability of lots of stored semen from bulls that have been shown to produce cows with excellent production and health traits has been a backbone of improving efficiency and production in dairy farms for several decades. There has been a continuous effort to build on the methods and procedures that contribute to selective breeding, most recently with the advent of genomic tools. Read More...