WATCH out Merino knockers: Western Australian researchers have identified that run under optimal Australian Lifetime wool conditions the Merino ewe storms ahead in a gross margin per breed comparison after finding “surprising” evidence that over conditioned cleanskin sheep breeds impaired reproduction capability.
The findings from a three year Western Australian Department of Agriculture study at Merredin suggest a Merino ewe maintained at condition score 2.7 could achieve a $130 gross margin per hectare per year, compared to Dorper at $90, Damara at $49 and Wiltshire $35.
Searching for a means to test ewe productivity of new cleanskin sheep breeds, the researchers found that weaning percentage of cleanskin breeds declined as joining weight increased, the opposite of the Merino.
In the trial that involved 100 seven to eight month old ewes from each of the four breeds run in the same mob and joined annually for three years, the Wiltshire weaning percentage struggled in the second year of the trial when the ewe increased its weight from 61.6 kilograms to 70.2kg, when weaning percentage fell from 94 to 77 per cent.
Similarly the Doper’s weaning percentage at the same age dropped by 17pc to 105pc when joining weight increased from 69.5kg to 77.1kg.
However DAFWA sheep consultant Tanya Kilminster, who led the new research, said the results could not be taken at face value as the true benefit of cleanskin sheep breeds was their accelerated mating, high 120 plus lambing percentages and ability to have three lambings in two years.
“The take home message is don’t run cleanskin sheep like Merinos,” Ms Kilminster said.
“With cleanskin sheep breeds it is all about producing lambs – and they are highly productive for less work – but there is work to do.”
Ms Kilminster said the concept that cleanskin sheep can run on “sticks and stones” was incorrect and her trial proved that nutrition was a key element in the productivity of the breed.
“The bottom line for cleanskin breeds, particularly Damara, is to have them continually lactating or pregnant,” she said.
Ms Kilminster said further research into nutrition requirements of cleanskin sheep breeds was urgently needed.