Friday, 20 April 2018 11:55

Solving the genetic jigsaw

Written by 
LIC’s Bevan Harris. LIC’s Bevan Harris.

Researchers at Livestock Improvement Corp (LIC) are working with the US Department of Agriculture (USDA) to piece together a genetic jigsaw of 15 million pieces.

They are using LIC Jersey and Holstein-Friesian bulls to build a genetic map of New Zealand dairy cattle.

Improving the genetic reference sequence is expected to help in identifying disease genes and speed up the delivery of breeding worth traits, among other things, LIC says. This will lead to more efficient cows and thus environmental benefits, and may help researchers to breed diseases out of the livestock population. 

Improvements in genetic gain reward farmers and so help the NZ economy.

In 2009, after a six-year effort, the US Department of Agriculture (USDA) and 300 scientists from 25 countries published the first cattle genome sequence of a female Hereford cow called Dominette. Though now dead, this cow ‘lives on’ in research laboratories worldwide where researchers have used her DNA sequence for other genetics discoveries. Improved genome sequencing is enabling researchers to overhaul Dominette’s sequence to improve accuracy.

LIC’s work in charting the DNA differences between beef and dairy cattle will help scientists understand what role different genes play in milk production, fertility and body condition, and the potential these genetic markers might have for the country’s dairy herd. Each DNA sequence makes up a piece of this jigsaw puzzle.

This research was funded by the Transforming the Dairy Chain (TDVC) Primary Growth Partnership programme, a seven-year, $170 million innovation programme led by commercial partners including LIC, DairyNZ and Fonterra, and partnered by MPI.

LIC’s acting chief scientist, Dr Bevin Harris, says the work with the USDA will bring benefits for the NZ dairy herd.

The bovine genome has three billion base pairs (the building blocks of the DNA double helix) containing 22,000 genes, 80% of which are shared with humans. Within these 22,000 genes there are genetic variants. 

To use a book analogy, each cow has the same number of chapters, i.e. 22,000. But there are a number of word and spelling changes (variants) in each chapter of each book.

You could read any book and be able to broadly describe what each is about, but there would be slightly different contextual differences with different interpretations. 

This is what leads to diversity within a species. Put crudely, everybody looks the same (the same book of 22,000 genes) but there are slight differences in most traits or characteristics.

By the end of this year, genomes from 1000 dairy cattle will have been sequenced. Through this sequencing, LIC has identified about 19 million variations that exist within the NZ dairy cattle population.

These will be compared to Dominette’s and the new dairy cattle reference genomes, and the next job will be to identify which of these genes affect the traits that dairy farmers are interested in. 

This information can then be used to improve the ability to predict how well animals will perform at birth based on their genome sequence.

DNA progress

In the last three years, improvements in DNA sequencing technology have cut the cost of sequencing a new genome and newer technology is allowing genomes to be sequenced more quickly.

A once-massive, costly exercise (US$50 million when Dominette’s genome was sequenced in 2006) now costs NZ$1000 per genome.

Harris says if genome sequencing had to be done manually, it would take someone typing 60 words per minute eight hours a day for 50 years to type the bovine genome.

“The entire DNA sequence would fill 200 one-thousand-page telephone directories,” he explains.

“The knowledge gained from this sequencing project will enable us to identify the potential benefits of genetic gains for the NZ dairy herd, and this will increase the accuracy of bull selection which will increase the national rate of genetic gain.” 

NZ Animal Evaluation (NZAEL), a subsidiary of DairyNZ, estimates that improvements in genetic merit are worth $300m profit a year to the dairy sector.

More like this

LIC ready for challenges ahead

Herd improvement company LIC says it's well-positioned for the challenges ahead and remains focused on its core purpose - delivering value for farmer shareholders.

Breeding heat-tolerant cows for Africa

LIC is embarking on a ground-breaking project aimed at breeding heat tolerant and disease resistant dairy cows for Sub-Saharan Africa, in collaboration with the global leader in precision breeding, Acceligen, and the Bill & Melinda Gates Foundation.

Scheme to pick high potential 'underdog' bulls

Holstein Friesian NZ, and herd improvement co-operative LIC have launched a joint sire proving scheme that aims to select and prove Holstein Friesian bulls for New Zealand dairy farmers.

Featured

Better animal genetic gain system

A governance group has been formed, following extensive sector consultation, to implement the recommendations from the Industry Working Group's (IWG) final report and is said to be forming a 'road map' for improving New Zealand's animal genetic gain system.

SIDE 2025's new schedule, venue

Annual farmer gathering, the South Island Dairy Event (SIDE), is set to make history as it heads to Timaru for the first time.

Taranaki piggery goes solar

Installing 400 solar panels at their Taranaki piggery and cropping operation will have significant environmental, financial and animal welfare benefits for the Stanley family.

National

The show is on!

It was bringing in a new Canterbury A&P Association (CAPA) show board, more in tune with the CAPA general committee,…

Food charity to hold online auction

Meat the Need, New Zealand’s dedicated charity delivering locally sourced protein meals to food-insecure communities, is launching an online National…

Machinery & Products

An ideal solution for larger farms

Designed specifically for large farms that want to drill with maximum flexibility, efficiency and power, the new Lemken Solitair ST…

Landpower increases its offering

Landpower and the Claas Harvest Centre network will launch the Claas Scorpion and Torion material handling solutions to the market…

» Latest Print Issues Online

The Hound

Leaky waka

OPINION: Was the ASB Economic Weekly throwing shade on Reserve Bank governor Adrian Orr when reporting on his speech in…

Know-it-alls

OPINION: A reader recently had a shot at the various armchair critics that she judged to be more than a…

» Connect with Rural News

» eNewsletter

Subscribe to our weekly newsletter