Six-monthly shearing and ewe reproduction

Dr Emma Doyle: The six-monthly shearing trial is funded by Australian Wool Innovation, and it's looking at the reproductive performance of ewes that are shorn at shorter shearing intervals compared to those that are shorn 12-monthly.

Interviewer: What are some of the findings you're getting from this?

Dr Emma Doyle: It depends on when your shearing events are occurring. If you're shearing your six-month ewes prior to joining, it's increasing conception percentages, and if you're shearing pre-lambing, it's increasing weaning and marking percentages and lamb survival from scanning to weaning.

Interviewer: Why do you think six-monthly shearing is important?

Dr Emma Doyle: For a number of reasons, particularly in Mediterranean environments, where the change in climate is so severe, from those wet winters to the hot, dry summers. We've got problems with our wool quality, where we're having breaks in the wool and low staple strength. So I think you can have a big improvement by shearing six-monthly and increasing staple strength in those wools.

Interviewer: From a genetic point of view, where does Mumblebone sit?

Dr Emma Doyle: Mumblebone is in a unique position, because not everyone can use shorter shearing intervals. There's a penalty for staple length under 60 millimetres, so if you can't grow that length, you'll be penalised in price. Mumblebone is in a great position, where they're actually achieving greater than 60 millimetres in each shearing interval. That's allowing them to get more money for their wool than they would if they grew it out to 12 months, where they'd actually be penalised for it being too long.

On every property, we've run a mob of ewes that was half 12-month shorn ewes and half six-month shorn ewes, so that we could very confidently compare the performance of both groups without any bias from environmental factors. The ewes yesterday were shorn six-monthly, and the 12-month treatment was crutched.

We're measuring all the fleece characteristics, so we're taking side samples to look at wool quality: fibre diameter, strength, length and yield. We're finding the six-month shorn animals have a greater yield, lower vegetable matter content and higher strength. We're not seeing any difference in micron between the 12 and six-month ewes, which was a concern for people.

We're also measuring body condition score and body weight of all the ewes throughout the 12 months: pre-joining, pre-lambing, at marking, sometimes at weaning, and then at the shearing events. We're finding that the six-monthly shorn ewes have a much greater body condition score throughout that 12-month period than the 12-month shorn ewes. This is usually because a shearing event stimulates intake, and we think that's allowing these ewes to be in better condition throughout the year compared to the 12-month ewes.

My hope is that people will see the reproductive advantages of shorter shearing intervals, and that more and more people will take them up. I think it'll help the health of the animal by reducing flystrike, and I think it will also be a stimulus for the industry, allowing shearing businesses to have more work around, and more constant work throughout the year.

The trial's been running for two years, and it'll finish at the end of this year. Then we'll collect all the data from all the properties and try to put some economic values around it, so that we can go out to industry and show what the economic benefit of six-monthly shearing is.