DNA

 

ARDG is in a great position to exploit a new technology on offer from Pfizer Animal Genetics (PAG). PAG is a technology company focussed on the use of DNA in the production and improvement of Livestock. DNA based technologies are currently being revolutionised. Contemporary DNA discovery is moving away from finding only a few highly significant markers, to techniques that identify hundreds and even thousands of DNA markers at once.  This “fingerprint” of the animal can then be associated with desirable traits such as Weaning Weight, Number of Lambs Born, Faecal Egg Count and many more.

This new technology is colloquially called a “SNP Chip” and has been commercialised by PAG as Sheep50K. It has been in development for some years, but has hit the headlines in Sheep since the sequencing of the Ovine genome in 2008. Sheep50K makes use of all 50,000 marker results for each trait of every animal tested.
The results of the Sheep50K test will be delivered as an mBV or Molecular Breeding Value. In essence, the results should seem familiar and will look very similar to traditional eBV’s (estimated breeding values from SIL, Sheep Improvement Limited). They are expressed in the units of a trait; e.g. kg’s for Weaning Weight; and can be interpreted in much the same way. The key difference between the two is that while an eBV is an indication of “the value of an animal as a genetic parent”. An mBV is a prediction of the animal’s breeding value based on an animal’s DNA-marker profile.

The big question is, why should commercial ram buyers be interested in why and how breeders such as ARDG are taking advantage of DNA technology? Take a look at the following diagram:

 

• Intensity is the level of emphasis placed on the selection of animals utilised in a breeding program. The more diverse the range of animals in a population, the greater the opportunity for more intense selection.

 

• Accuracy defines the amount of confidence placed in a mating decision. Animals with lower accuracy have more chance for change in the future. The accuracy of selection is determined by how heritable the trait is in the population and how accurately the eBV of the animals selected as parents are evaluated.

 

• Generation interval is the average age of parents when their offspring are born. Using mBVs for ram hoggets in conjunction with eBVs and individual performance will help to shorten the generation interval.

 

The answer: Reducing Risk. These three factors are maximised by ARDG to provide you with the best Ram for sale possible. DNA technology in the form of mBV’s will play a significant part in this picture by reducing your risk in purchasing new genetics. How will it do this?

 

• SNP Chips are very well suited to traits which are difficult to record such as traits that are sex linked, expressed late in life, or generally costly to record. However they can also easily be used for traditional traits that will already be familiar as eBVs. Therefore mBVs are being considered as a very powerful and independent additional piece of information which will aid breeders in their selection decisions.

 

• mBVs are delivered with their own independent accuracy information. This means not only can we combine eBVs with mBVs (giving genomic BVs, or gBVs), but we can also combine the accuracy information from both resources and significantly increase the accuracy overall.

 

• mBV testing and the establishment of how an animal might perform as a sire can be done at a very early age, potentially as a new born lamb and certainly before an animal has any progeny of its own. Therefore generation interval will be markedly reduced.

 

A good example of how and where an mBV might come into its own is in the production of a maternally based eBV for a potential sire. Currently the daughters of a sire must perform themselves before an accurate picture of a maternal eBV can be derived for a sire. With an mBV, an accurate prediction of how a sire itself may perform maternally can be attained at a very young age.

The information available when making your purchasing decision is substantial, but is not the full picture. Even with the addition of DNA technology information, the full picture is not completely attained, but it is another significant step in the right direction. mBVs have the ability to more fully describe the performance potential of an animal as a Sire, but from a much earlier age.

Performance recording organisations around the world are very conscious of how SNP Chips and resultant mBVs have the potential to aid breeders and commercial farmers in their endeavours. mBV’s can combine with traditional eBV’s to form gBVs and can be delivered in exactly the same way eBVs are currently delivered.

WATCH THIS SPACE! PAG is excited to be providing Sheep50K to ARDG, the first commercially available test providing mBVs derived from a DNA marker panel with more than 50,000 DNA markers. Two things are for certain:

 

• Technology is moving fast and holds much opportunity

 

• The onus is on the technology providers to help breeders and commercial farmers alike deal with new technologies and exploit all available opportunities.

 

If you, the commercial ram buyer, want to learn more about how DNA technology could positively influence the breeding programme at ARDG and your future Sire, contact the team at ARDG (www.ardg.co.nz) or Pfizer Animal Genetics (www.pfizeranimalgenetics.co.nz). Influential innovation is but one ‘click’ away.

Sharl Liebergreen
Regional Manager, Technical Services
Pfizer Animal Genetics