Introducing the HFplus Gene

The HFplus gene is one of 4 known mutations of the GDF9 gene in sheep around the world.

This gene, also known as the Norwegian white gene, was first discovered in Norwegian Whites in Norway, hence the title of Norwegian White gene.

This gene differs from the other 3 mutations in that both single and double copy carriers express increased fecundity with no downside effects. 

All other 3 mutations have issues either with excessive litters sizes, sterility in double copy ewe carriers or no increase in single carriers and only small increase in a double carrier. (as shown in literature following these briefing notes)

According to literature on the subject obtained from research published by the Swedish University of Agricultural Sciences on “Genes involved in ovulation rate and litter size in sheep” by Towe Jasson, this gene will give an increase of up to 20% for a single and 50% for a double copy depending on management and nutrition.

We have found, in a small group of ewes we have followed carrying single, double and no copies to be a fair guide from the literature above, although our trials show, all be it only small numbers, to be more than those figures.

As soon as we have enough commercial UltraWhite ewes available in the next couple of years we will be facilitating trials by an independent body to further evaluate the true differences in the fecundity effects of this gene.

As it is the first time this gene has been officially released in Australia in a breed of sheep, to the best of our knowledge, we have named it the HFplus gene for ease of recording and to clearly identify it from the other mutations of the GDF9 gene in Australia. 

We think this gene will lead to a significant financial increase in the profitability of flocks carrying this gene provided sound management is applied.

The HFplus gene further adds to the credentials of the UltraWhite as it proceeds to become the breed of choice across wide areas of Australia.