In maternal flocks around Australia breeders are quietly experimenting with a variety of prolific genes while criticising us for using the Booroola gene.

To this point in time they have been unsuccessful because in some cases the gene they have been trialling has had no effect and in other cases the results have been inconsistent.

When we talk about a prolific gene, we need to understand that it is insufficient to just say we are using the Booroola gene because there are many variants of this gene which give different effects.

The Booroola gene originally identified tended to cause too many oocytes to be released and so the gene was associated with hyper prolificacy.

This is not the case with the variant in the Prolific White.  I am halfway through lambing and I have had only one set of quads.

The gene we are using in the Prolific White comes from one specific ram I identified over 10 years ago and all of our Prolific White rams have copies of this gene. It behaves in a very predictable manner. It will lift the scanning rate of a ewe carrying it by 60%. So, if your ewes were scanning 150% then they will scan 210% if you introduce the gene. How does this work out in practise?

To test this theory we conducted the following trial on John Mossop’s property at Bool Lagoon.
Nudie ewes carrying or not carrying the gene were mated and the scanning rates recorded. The weaning rates will be reported at the finish of lambing.

Both groups of ewes were mated at 64 kgs and condition score 2.7. The results were as follows:

Breeders are looking for what we already have but they don’t want to use it because of the history of hyper prolificacy with other variants of this gene. They will have to go through the arduous process of finding a useful variant amongst other prolific genes.

In the meantime, we are using DNA technology to advance on other fronts. We are scanning our flocks for genes associated with seasonality, muscling, and worm resistance. Once ewes are identified with useful genes, they will be used in embryo transfer programs to rapidly improve our genetics. DNA technology allows much more rapid genetic progress to be made than using standard quantitative genetics.

The major aim with our Prolific White program is to produce efficient easy care sheep. This has been shaped very much by my belief that sheep production systems are best served by having maternal and terminal lines. This concept has served us well as evidenced by the use of terminal rams over crossbred ewes. So we are breeding the Prolific White to be used in conjunction with terminal sires.

Our competitors in this space are aiming for self-replacement. To this end they are breeding massive sheep. Go along to Sheepvention and see their sheep and ask yourself is this what you want to end up with your ewes. Our aim is to breed a 60kg ewe which scans 200% at condition score 3 and you
can see from the data above you can see that we have achieved that.

Breeds such as the Ultrawhite bred from Poll Dorsets will play an important role as a terminal ram over maternal shedders.