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EVEN in the face of being scorned by his peers, Tullamore sheep breeder Don Edwards has maintained the belief that aiming for more twin lambs was an essential means to improving the fertility of his Merino flock.
Mr Edwards has boosted lambing rates at his property "Spring Creek", from about 85 per cent 30 years ago to an average of more than 100pc.
His quest to boost the number of twins born started in the 1960s.
He was involved in a state-wide evaluation of twin versus single-born Merinos involving a number of breeders.
"It was a comparison of 100 single-born ewes versus 100 twin born ewes," Mr Edwards said.
He collected data until 1975.
"Because of the great wool recession I was the only one that reached fruition," he said.
"In a nutshell, twins were five per cent down in fleece and body weights, but they were about 10pc more fertile and had a lot more twin births."
Mr Edwards regularly culls non-performers such as dry ewes and non-rearing wet ewes.
Ultrasound scanning has also been used for more than a decade.
He runs about 1000 Merino ewes and uses rams from the Cressley family, "Tom's Lake", Booligal, where he selects about seven rams every three to four years.
At last year's shearing shearing, Mr Edwards' flock produced 42 bales of wool from 1600 sheep, including 600 younger sheep.
Mr Edwards calls his special flock of twinners, which includes only the most fertile ewes, his HiFerts.
During the past decade, Mr Edwards said ewes in the HiFerts mob had averaged 27pc more foetuses scanned than the rest of the ewes run on "Spring Creek".
"To be included in the HiFerts mobs, maiden ewes needed to be scanned with twins and rear at least one of the lambs to marking," Mr Edwards said.
To remain in the mob, the ewes had to continue to be scanned with twins and rear at least one lamb.
"If they scanned with a single lamb, they were put back into the other mob of ewes-never to return to the HiFerts.
If they failed to rear any lambs to marking, they were culled from the "Spring Creek" flock entirely.
Between 2003 and 2010, the HiFerts averaged 160pc lambs marked while the remaining adult ewes averaged 130pc.
His maiden ewes averaged 102pc lambs marked to ewes mated during that period.
