IMPROVING maternal efficiency, productivity and biosecurity are all factors in a transition from a first-cross ewe flock to self-replacing composites for a Parawa prime lamb producer.
Sammy McIntyre, also Parawa Ag Bureau president, has been running a flock of Border Leicester-Merino ewes on the southern tip of the Fleurieu Peninsula since 2017, when her family bought the property to complement their established cropping and sheep enterprise at South Kilkerran on the Yorke Peninsula.
Depending on seasonal conditions, Ms McIntyre has been running 900 to 1200 ewes, with the second cross lambs finished in the family's feedlot back on the YP.
Late last year, Ms Mcintyre bought Cashmore Oaklea-blood composite ewe lambs in the first step to running a self-replacing mob, with the ewe lambs joined to White Suffolks and low birthweight Poll Dorsets.
Two types of composite rams will go over the first-cross ewes moving forward, with electronic identification tags used to track any differences in resulting progeny.
"Roughly a third have been mated to maternal sires and everything else is to terminals for prime lambs," Ms McIntyre said.
"That third of the flock will give me enough replacements and I'll mate them as ewe lambs each year, with any that don't get into lamb sold into the prime lamb market."
Ms McIntyre said by having a composite flock, she won't be beholden to any particular breed of ram.
"If it does the job, it doesn't matter what it looks like or the breed mix," she said.
Running a self-replacing flock will eliminate the biosecurity risks and significant cost of buying in replacement first-cross ewes every year.
"I think people undervalue the composites," Ms McIntyre said.
"Border-Merinos have performed really well, but I don't think that means you can't get any better."
As part of the business shift, Ms McIntyre has had a strict culling regime for her ewe flock to improve productivity, with any ewes not carrying a lamb or having udder issues shown the gate.
She said 72-76 per cent of her ewes had been scanned as carrying multiples in recent years, so two functioning teats were a must to ensure two lambs could be reared.
She also aims to moderate ewe size through genetic selection to improve maternal efficiency and make shearing an easier task.
"If I can moderate animal size, but increase fertility and number of lambs weaned and grown out, I'm going to get the same or more kilograms of lamb per ewe without making it hard for shearers or myself when handling them," Ms McIntyre said.
"I'd much rather have two smaller twins than a single.
"Last year, the twin lambs averaged 31kg at weaning and the singles averaged 34kg - so 62kg versus 34kg from the individual ewes."
PARAWA prime lamb producer Sammy McIntyre has introduced electronic identification ear tags as a way of measuring the influence of individual rams on flock performance, as she transitions from a first-cross flock to self-replacing composites.
"I've mated the two different types of maternal rams I've got to separate groups," she said.
"I'll be able to split them at lambing to see what the variation is, if any.
"Using the ear tags, I'll be less swayed by general appearance and be able to use measurements and data to figure out what will be the better sire for the replacements."
Ms McIntyre aims to breed mateable ewe lambs and will preference twin-borns when deciding what to keep as replacements.
"I'll be keeping scanning results for each year of their life so it might take a few years to know if there is a difference between the sires," she said.
The number of lambs weaned and growth rates will be important measurements in that process, with Ms McIntyre wanting lambs getting to a mateable weight by joining time and passing that onto their progeny.
Lambing productivity will be her top tier of selection when selecting replacement ewes, followed by bare breeches.
The composite ewe lambs bought last year were from a parent flock that focused on worm resistance so Ms McIntyre is hopeful selection and genetics will help her reduce chemical use and crutching.
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